******************************************************************************** SUPRAFAXMODEM AND SUPRACOMCARD REFERENCE MANUAL Revised: 5/13/97 PART # 70-0087-1A SupraCOMcard and SupraFAXModem are trademarks of Supra Corporation. All other trademarks belong to their respective owners. Manual Copyright 1993 Supra Corporation. Diamond Multimedia, Communications Division 7101 Supra Drive SW, Albany, OR 97321 General: (503) 967-2400 Fax: (503) 967-2401 Sales: 6:00am - 5:00pm PST, M-F (800) 727-8772 Supra Tech Support: 5:00am - 7:00pm PST, M-F; 8:00 am - 4:00pm PST, Sat (503) 967-2450 GENERAL Supra BBS.... ....(503) 967-2444 8 lines 24 Hours v.34 v.32bis v.42bis LAPM 2-5 Supra FaxBack Service 503-967-0072 CompuServe.......Go Supra EMail.....supratech@supra.com pctech@supra.com mactech@supra.com ******************************************************************************** INTRODUCTION ******************************************************************************** Welcome to the Reference Manual. You should have already read the Getting Started manual for information on setting up your modem and using it for basic tasks. Now that you are familiar with your modem's basic operations, you are ready to learn more about its advanced capabilities. This manual provides general information on your modem's fax capabilities. It does not describe the fax commands or explain how to program the modem's fax functions, because your fax software should provide all the functions you need. Refer to your fax software manual and Chapter 1 of this manual for additional information on the modem's fax features. This manual also contains detailed information about your modem's data communications capabilities and how to use them. It includes detailed instructions on using your modem's "AT" commands to perform tasks your software can't, and explains the modem's error correction and data compression features. It also includes a troubleshooting chapter to help you if you are experiencing problems and a glossary of telecommunications terms that should help you understand this sometimes confusing technology. This manual does not explain fax or telecommunications software. Please refer to your software manuals for information on using a particular program. Your modem and software manuals should help you with any questions you have about using your modem, but if you need further assistance, please consult the resources listed in Appendix G or contact us directly. Enjoy your modem! ******************************************************************************** TABLE OF CONTENTS ******************************************************************************** INTRODUCTION 1 FAX ISSUES Group 3 CCITT Protocols and Rates Class 1, 2, & 2.0 Fax Commands Fonts Used When Faxing Software Authors 2 USING AT COMMANDS Issuing Commands Yourself (Terminal Mode) Command State & Online State Escape Code (+++) Command Line Syntax Command Line Buffer Result Codes 3 USING MNP, V.42BIS, & FLOW CONTROL Start with the Basics How Error Correction & Data Compression Work Error Correction Data Compression Connection Rates How the Modem Determines Connection Speed & Protocol After Connecting Connection Types \N1 Direct Connection \N Normal Connection \N2 & N4 Reliable Connection \N3 AutoReliable Mode Flow Control The Configurations Most People Need Using Xmodem, Ymodem, or Pre-Compressed Files MNP 5 Data Compression V.42bis Data Compression Error Correction 4 DIALING Using the Dial Command Dialing from a Telephone Storing a Telephone Number Automatic Pulse Dialing If Telephone System Does Not Support Touch Tones Disabling Call Waiting 5 ANSWERING Answering Calls Identifying The Source of an Incoming Call (Caller ID) What is Caller ID? Potential Applications Can You Use Caller ID? Software Options Caller ID AT Commands How to use Caller ID with Telecommunications Software Distinguishing Between Incoming Voice, Fax, and Data Calls (Silent Answer & Adaptive Answer) Silent Answer (Optional Feature #141) What is Silent Answer? Do You Need to Use Silent Answer? Can You Use Silent Answer? Adaptive Answer What is Adaptive Answer? Can You Use Adaptive Answer? Software Issues Software That Supports Silent Answer/Adaptive Answer Software That Does Not Support Silent Answer/Adaptive Answer 6 CONNECTING Bell & CCITT Protocols Connection Rates Connection Types 7 CREATING CUSTOM MODEM CONFIGURATIONS Do You Need to Configure Your Modem? Factory Default, Active, & Stored Configurations Creating a Custom Configuration AT Commands Used When Creating a Custom Configuration AT Commands for Changing S Registers Directly &F, &F1, &F2: The Factory Configurations 8 SOLVING PROBLEMS Part 1: Symptoms, Sources, & Solutions First, Double Check Your Equipment & Configuration Problems Encountered While Offline Problems When Trying to Connect Problems While Connected Part 2: Additional Troubleshooting Information High Speed Communication Problems Serial Port Speed Problems Faster UART Chip for PC Compatibles Used with External Modems Slow Downloads Multitasking Flow Control & Hardware Handshaking Cables on External Modems Line Noise Line Noise Problems on Fax Calls Line Noise Problems on Data Calls Where Does the Problem Originate? Line Noise Checklist Understanding the Line Noise Checklist: Rate Renegotiation Commands & S Registers Miscellaneous Troubleshooting Issues What ROM Version Do You Have? Power Supplies Compatibility With Other Modems/Older Modems A OPTIONAL FEATURES 101 Fax Class 1 104 Fax Class 2 105 Fax Class 2.0 115 CCITT V.17, 14,400 bps Fax 120 Worldwide Support 121 CCITT V.23 122 CCITT V.25 123 Blacklisting 124 Access Security Storing Passwords & Callback Numbers (*Pn) Listing Passwords & Callback Directories (*L) Requesting Secure Access Mode (*R) Enabling Secure Access & Requesting Password (*C) Exiting Secure Access (E) 140 CCITT V.32bis, 14,400 bps Data 141 Silent Answer 142 Caller ID 143 MNP 10 144 MNP Cellular 145 AutoSync 146 Enhanced Configuration Display 160 Voice Processing B AT COMMAND DESCRIPTIONS C RESULT CODES Result Code Commands Sample Result Codes Which Result Codes Should You Use? Complete List of Possible Result Codes D S REGISTER DESCRIPTIONS E RS-232C PIN ASSIGNMENTS F FCC & DOC RULES Federal Communications Commission (FCC) Canadian Department of Communications (DOC) G RESOURCES GLOSSARY ******************************************************************************** CHAPTER 1: FAX ISSUES ******************************************************************************** The most important thing you need to know about fax standards (sometimes called protocols) is that the faxmodems and machines you connect to must support the standards you use. GROUP 3 Group 3 is a standard that lets most modern fax devices (including your modem) communicate with each other. It specifies image resolution, complex data compression, and other features. The vast majority of fax devices in use today support Group 3. CCITT PROTOCOLS AND RATES The CCITT protocols (defined by the international CCITT standards committee) are standards that let fax devices (faxmodems and fax machines) communicate at specific rates. CCITT defines communication at various speeds up to a maximum of 14,400 bps communication, CCITT V.29 defines speeds up to 9600 bps, and CCITT V.27ter defines speeds up to 4800 bps. Most fax devices today communicate at 9600 bps, but because of relatively recent technological advances, 14,400 bps fax connections will become much more common in the near future. CLASS 1, 2, & 2.0 FAX COMMANDS Class 1, 2, and 2.0 are the command sets used by fax software to control a faxmodem. These fax commands are invisible to you when you use fax software. Class 1 is an officially approved standard. Class 2 is a defacto standard that has never been approved. A new, approved version of Class 2, called Class 2.0, may be available in the future. These fax command sets are optional features that are only available on select modem models. Class 1 is option #101, Class 2 is option #104, and Class 2.0 is option #105. The I10 command tells which optional features your modem supports. Do you need to specify Class 1, 2, or 2.0? The answer is usually no, but it depends on your fax software. Some fax software automatically determines which class to use. For other software, you need to select the predefined configuration that came with your modem or software. The predefined configuration will automatically set the modem to the appropriate class. If your software comes with this type of configuration, it should be fairly simple to install. If you need help, your fax software manual should be able to help you. Less frequently, some fax software does require you to select either Class 1 or Class 2. If you find that you have problems using one, you may want to try using the other. FONTS USED WHEN FAXING To ensure the best quality fax output in Macintosh and Windows environments, it is very important that you use both screen and printer fonts, and if applicable, also use Adobe Type Manager (ATM) or TrueType. A common mistake is using a font that is built into your printer for which you have a Screen font, but not a Printer font. The type will appear fine on your screen but be faxed in blocky letters because it used the Screen font to create each character. The solution is to use a font with both Printer and Screen fonts or to obtain the printer font you need. SOFTWARE AUTHORS Available fax software should provide all the fax functions you need. However, if you are an advanced programmer and want to write fax software, you can obtain information about fax commands from the following sources. (This information is provided for software authors, not novices. Most users will not find it helpful.) * The following publications, available from Global Engineering Documents, 714-261-1455, 2805 McGraw Ave., Irvine, CA 92714. Additional phone numbers: 800-624-3974 in U.S., 800-854-7179 outside U.S. - EIA/TIA-578 (Class 1) - EIA/TIA-592 (Class 2) - CCITT Volume VII, Fascicle VII.3, Recommendations T.0-T.63 * The following Macintosh-specific tool, available from STF Technologies, 816-463-2021, Junction I-70 and Highway 23, Concordia, MO 64020: The STF Developer's Kit. ******************************************************************************** CHAPTER 2: USING AT COMMANDS & RESULT CODES ******************************************************************************** When you use your telecommunications software to perform a task (such as dialing a phone number), it uses the modem's AT commands to perform the task. It is usually easier to let your telecommunications software issue the commands for you than it is to issue the AT commands yourself. When your telecommunications software can't perform a task (or you don't want it to), you'll issue the AT commands yourself. These commands can be used to perform various tasks, from hanging up to changing your modem's speaker volume. Various chapters in this manual explain how to use the AT commands to accomplish specific tasks. The rest of this chapter explains how the AT commands work, and Appendix B explains them all in more detail. ISSUING COMMANDS YOURSELF (TERMINAL MODE) To issue AT commands yourself, you must be in your software's "terminal mode" -- also called "local" mode. In this mode, the commands you type go to the modem rather than to your software or the remote computer. Some software is in terminal mode as soon as you start the program. If the modem responds with the OK result code when you type the following, you are in terminal mode and ready to issue commands ([CR] represents a carriage return): AT [CR] If you are not in terminal mode, refer to your software manual to determine how to get there. COMMAND STATE & ONLINE STATE The modem can operate in either the command state or the online state: * When you first turn your modem on, it is in command state. It must be in command state to issue AT commands. * When your modem connects to another modem, it automatically changes to the online state. Your modem must be in the online state for data to be transmitted. If you're connected to a network, Bulletin Board System, or other remote computer (i.e. you're online) you can transmit data, but you must change to command state to send AT commands. To switch from one state to the other, use the methods below. * To switch from online to command state, type the escape code (+++) as explained below. This automatically puts you in terminal mode, ready to type commands. * To switch from command state to online state, issue the O (online), A (answer), or D (dial) command (in other words, go back online, answer a call, or dial a number). The O, A, and D commands are described in Appendix B. ESCAPE CODE The escape code is a string of three ASCII plus signs (+++) preceded and followed by a "guard time" during which no other data is transmitted. It is used to leave the online state without hanging up. To use it, do the following: 1. Send a character. 2. Do not transmit any data for a period equal to the guard time. The default setting for the guard time is 1 second. 3. Type the escape code quickly. Do not follow with a carriage return. 4. Do not transmit any data for another period of time equal to the guard time. The modem responds to these steps with the OK result code. If it doesn't, either it received data during the guard time or the escape code was typed too slowly. The time between each plus sign (`+' ) in the escape code should not exceed the guard time. The plus signs in the escape code can be changed to another ASCII character by changing the value in register S2. COMMAND LINE SYNTAX The prefix AT (think "ATtention") must start each command line except A/ and be in all uppercase (AT) or all lowercase (at) characters. The modem examines the AT code to determine your computer's serial port rate, parity, word length, and number of stop bits, and then stores your current configuration in its memory. Multiple commands can appear on one command line. You can separate these with spaces to improve readability if you like (the modem ignores the spaces). Each command line (except A/) must end with a carriage return ([CR] _ ASCII 13). If you don't provide a carriage return, the modem ignores the commands. A line feed character following the carriage return is optional and is ignored by the modem. The following are examples of valid command lines: AT DT 555-5055 [CR] ATH [CR] AT &F &C1 &D2 &W [CR] A/ COMMAND LINE BUFFER The modem places each command issued into a command buffer that holds up to 40 characters. The modem does not place the AT, carriage return, or line feed characters, so the buffer's 40 spaces only hold actual command characters. If a command line contains more than 40 command characters, the modem ignores the commands and displays the ERROR result code. RESULT CODES After the modem receives a command, it returns a result code. The most common result code is OK, which means the modem understood your command. Other result codes are listed in Appendix C. Result codes can be represented by English words or with numbers. Words are preceded and followed by carriage return and line feed characters. Numbers are followed by a carriage return. Refer to the V command in Appendix C for more information. ******************************************************************************** CHAPTER 3: USING MNP, V.42BIS, & FLOW CONTROL ******************************************************************************** Your modem features error correction and data compression protocols that allow you to transmit data error-free at rates faster than the actual line connection rate. What may be a mystery now becomes clear once you have an understanding of what the modem is actually doing. Pay careful attention to this chapter to make sure you are using your modem to its fullest potential. START WITH THE BASICS To understand this technology, you need to know these basic ideas: * Your modem supports V.42 (LAPM and MNP 2-4) error correction, and MNP 5 and V.42bis (BTLZ) data compression. * MNP 2, 3, and 4 are the MNP error correction protocols. MNP stands for "Microcom Networking Protocol (MNP)" after the company that developed these protocols. MNP 4 is often the highest level connection you can get on many of the commercial services like CompuServe. * MNP 5 is an MNP data compression protocol. It offers a compression rate of up to 2:1 ("throughput" to 19,200 (V.32) or 28,800 bps (V.32bis)). MNP 5 connections also use MNP error correction. * LAPM is an error correction protocol used in V.42. * BTLZ is the data compression protocol used in V.42bis. It offers compression of up to 4:1 (throughput to 38,400 (V.32) or 57,600 bps (V.32bis)). BTLZ connections require LAPM error correction. * V.42 is the CCITT error correction protocol. (CCITT is an international standards setting committee.) V.42 uses LAPM as the preferred protocol and MNP 4, 3, or 2 if LAPM is not available. MNP 10 is not part of V.42. * V.42bis adds BTLZ data compression to the V.42 protocol. MNP 5 is not part of V.42bis. * Your modem may also support MNP 10, for cellular communication, providing an extreme level of error correction on adverse connections. MNP 10 is optional feature #143, which is only available on select modem models. The I10 command tells which optional features your modem supports. * Both your modem and the remote modem must support the same data compression/error correction protocols. If the other modem does not support the same protocols that your modem supports, you can connect and communicate, but you will not be able to use all the protocols your modem supports. * "Remote Modem" is the modem your modem connects to. * "Throughput" is the effective transfer rate. In general, on a 9600 bps connection, data will transfer at a maximum of 9600 bps, meaning maximum throughput is 960 characters per second. But on a 9600 bps MNP 5 connection, where MNP 5 can compress the data to half its original size, throughput can be double that of the 9600 bps connection without MNP 5, or 19,200 bps. The .connection rate and actual transmission speed are still only 9600 bps. * "Connection Rate" is the rate at which your modem and the remote modem connect, such as 9600 bps or 14,400 bps. This rate is determined by the modems when they connect. Synonyms: Line Speed, Modem-to-Modem Speed, DCE Speed#. * "Computer Rate" is the rate at which your modem and computer communicate. You change this rate in your software. With your modem, this rate should usually be higher than the connection rate. Synonyms: Serial Port Speed, .Modem-to-Computer Speed, DTE Speed. HOW ERROR CORRECTION & DATA COMPRESSION WORK Error Correction For error correction, the modem breaks your transmission down into blocks of data (frames) and calculates a checksum (the sum of all data bytes in the block). The block and its checksum are then transmitted. The receiving modem then calculates a checksum on the received data block and compares it with the received checksum. If these numbers are different, the data block was not transmitted properly, and the modem resends the data. Error correction is useful for communications that occasionally experience a little telephone line noise or some other "glitch." However, error correction will not perform miracles on extremely noisy lines. If you have lots of errors, you may need to have your telephone circuits checked or change long distance carriers. Data Compression Data compression is accomplished by the sending modem analyzing the outgoing data for often repeated patterns of data (such as the letters "A" and "E" in English text). It then assigns a shorter data code that will transmit faster than the original data. The more often the same data codes occurs in the transmission, the better compression the modem can achieve. Certain file types like text files and graphics screens are very good candidates for optimal compression. Files that have already been compressed with a program like Stuffit, PKZIP, or ARC may only gain 10-15% additional compression with V.42bis and could even show a slight performance decrease with Microcom Networking Protocol (MNP). The compression rates of 2:1 for MNP 5 and 4:1 for V.42bis were determined as typical using a standard non-compressed test document. Additional information is provided later in this chapter. CONNECTION RATES How the Modem Determines Connection Speed & Protocol Your modem first tries to connect to the remote modem at the highest rate your modem supports (14,400 bps or 9600 bps). If the remote modem can't connect at your modem's highest rate, your modem then tries to connect at the next highest rate (12,000 bps or 4800 bps, depending on your modem. If that doesn't work, it continues trying the remaining speeds the modem supports, one at a time in descending order. (This process is called "fall back.") If error correction and data compression are enabled (they are when shipped), the modem next tries to "negotiate" error correction and data compression protocols with the other modem. With your modem the order in which the protocols are tried is error correction, then data compression, and then a connection with no error correction or data compression. The protocols that will be used are the most powerful protocols that both modems support. Because your modem supports so many rates and protocols, this process can take several seconds to complete. If it seems to take an extremely long time, you may be having line noise problems; refer to Chapter 8. After Connecting Once connected, your modem sends your computer a result code that tells it the connection rate (for example, CONNECT 9600). Depending on how your software handles the result code, you either see the result code on your screen, or you see your software's interpretation of it. If .nonsense characters appear on your screen after this, the computer and connection rates are different. With modems that don't support error correction or data compression, and with "Direct" connections (explained in the next section), if the computer and connection rates are different you must use your software to change your computer rate to match the connection rate. (Otherwise, you'll only see nonsense characters.) Some software automatically does this after looking at the CONNECT XXXX message. Once your computer rate and connection rate match, you can start communicating directly with the remote computer. On your modem, the computer rate and connection rate do not have to match because of "flow control" (described later in this chapter). This lets your computer talk to your modem at a higher speed (say 38,400 bps) than your modem is talking to the remote modem (say 9600 bps). This is useful because data rates vary when using data compression, but it causes problems with software that automatically adjusts the computer rate to match the connection rate. For example, let`s say you set your computer rate to 38,400 bps (in your software) and then make a 9600 bps connection. Your modem could normally handle this, but when your software sees the CONNECT 9600 message, it decides it has to change the computer rate down to 9600 bps to match it -_ disabling your ability to take advantage of the higher throughput of data compression. The modem has a way around this, however. In its default settings (&F1 or &F2), the modem returns a CONNECT XXXX message to the computer telling it the computer rate (DTE) and not the connection rate. In the previous example with the computer at 38,400 bps and the connection at 9600 bps, it will return CONNECT 38400 and your software will stay at 38,400 bps. For more information, refer to the Wn command description in Appendix B. CONNECTION TYPES The following commands tell your modem what type of connection you want it to try. Do not use them during an active connection. \N1 Direct Connection If you use \N1, the modem will act just like a regular modem that doesn't support error correction or data compression. Your computer rate and connection rate must match. \N Normal Connection If you use \N, the modem will still act just like a regular modem, except that you won't have to change your computer rate to match the connection rate, because you'll be using "flow control" (Flow control is explained later in this chapter.) \N2 & N4 Reliable Connection If you use \N2, the modem will try to make an MNP connection (MNP 5, 4, 3, or 2). If it can't, the modem will hang up. If you use \N4, the modem will try to make a V.42bis, V.42, or MNP connection, and if it can't, it will hang up. Reliable connections also feature flow control. \N3 AutoReliable Mode If you use \N3, the modem will try to make the best connection possible. If it can make a V.42bis connection, it will. If not, it will "fall back" through V.42 and MNP, trying each one until it is able to connect. (It will not attempt a V.42bis connection if you've issued the %M0 command, or an MNP 5 connection if you've issued the %C0 command.) The connection the modem actually makes can be Reliable or Normal. In most situations, you'll want to use \N3. Flow Control Normal and Reliable connections use a technique called "flow control" that lets your computer rate (computer-to-modem rate) be different than your connection rate. Flow control is useful with data compression because your throughput is higher than the connection rate and because the throughput changes depending on the compressibility of the data being sent. Flow control lets your modem and computer tell each other when they can accept more data for transmission and when to wait. This "handshaking" prevents data from being lost because the computer or modem was busy. Your modem supports both "hardware" (RTS/CTS) and "software" (XON/XOFF) flow control. Hardware flow control (also called hardware handshaking) uses two of the modem's RS-232 lines for signaling. Software flow control uses special XON and XOFF characters to communicate between your computer and the modem. Hardware flow control is the preferable (and default) method because of its speed and reliability. To use hardware handshaking flow control, you must have: * Hardware handshaking cable (if your modem is external) such as the one that may have been provided with the modem. * Hardware (RTS/CTS) flow control enabled in your telecom software. If your modem came with telecom software, the software should have flow control enabled. * Flow control enabled by the &K3 command (RTS/CTS hardware flow control). &K3 is the factory default with &F1 and &F2. * DTR disabled (&D0) if you are using a Macintosh. &D0 is the factory default with &F1 (Mac). THE CONFIGURATIONS MOST PEOPLE NEED Simply issue &F1 (if you have a Macintosh) or &F2 (if you have any other type of computer). Then issue &W to store the configuration so it loads automatically when you turn on the modem. This tells your modem to use AutoReliable mode, hardware handshaking, and CONNECT XXXX messages that reflect the computer's rate. Chapter 7 provides more information. USING XMODEM, YMODEM, OR PRE-COMPRESSED FILES MNP 5 Data Compression We recommend disabling MNP 5 data compression (%C) when using an MNP Reliable connection and transferring files that are already compressed by compression software such as ARC, .ZIP, or StuffIt. When files compressed by these programs are transferred using MNP 5, the files sometimes actually take longer to transfer than files transferred using a Reliable connection without data compression. V.42bis Data Compression V.42bis is more sophisticated. When it recognizes that there is no benefit to compressing software-compressed data further, it does not attempt to use V.42bis compression. To receive this and other benefits, use V.42bis rather than MNP 5 whenever possible. Error Correction Unlike data compression, it is usually advantageous to use MNP 2-4 or LAPM error correction for any file transfer, regardless of compression or software-based error correction protocols such as Xmodem, Ymodem, etc. The error correction protocol strips start and stop bits from each character (improving throughput) and performs error correction on smaller chunks of data than do software-based error correction protocols (so if an error does occur, less data has to be retransmitted, taking less time) ******************************************************************************** CHAPTER 4: DIALING ******************************************************************************** Most of the time you'll use your telecommunications software to dial numbers, and you'll be able to mostly ignore this chapter. But at some point you may need to tell your software something it does not inherently know, or you may need to set your modem in some way that your software can't do for you. This chapter tells you what you need to know in situations like these. Refer to your software manual for instructions on using your software to dial numbers and answer calls. USING THE DIAL COMMAND Your modem dials phone numbers when you give it the dial command (D) and a phone number, either alone or with dial modifiers. The phone number must be an ASCII string containing the characters 0 through 9 (for pulse dial lines) or those numbers and A, B, C, D, #, and * (for touch-tone dial lines). The number cannot exceed the size of the command buffer (40 characters excluding the AT prefix, spaces, the carriage return control character, and the line feed control character). The modem uses the dial command modifiers (listed below) in the order it encounters them on the command line, from left to right. L dial last string dialed P pulse dial R reverse mode from originate to answer mode (R must be last character in the command line) Sx dial number stored in memory location x (x=0, 1, 2, or 3) T touch-tone dial W wait for dial tone before processing the next character in the dial string (useful for PBX phone systems) @ wait for quiet answer , pause before processing the next character in dial string ! hook flash (go on-hook for 700 ms.) ^ turn on calling tone if originating call (enabled on a call-by-call basis only) ; return to command state after dialing (must be last character in the command line) To aid readability, spaces, hyphens, and parentheses can be added to the dial command line without affecting its function. In the following example, your modem goes off-hook, waits for a dial tone, and then touch-tone dials the number 1 (405) 555-9624. AT DT 1 (405) 555-9624 [CR] If your modem does not receive a valid carrier from the remote modem within 30 seconds (the default value of register S7), your modem hangs up and sends the NO CARRIER result code. If the modem does receive a valid carrier within the time allowed, it will send a CONNECT XXXX message indicating the connection rate. DIALING FROM A TELEPHONE You can also dial a number yourself on a telephone and give the modem a command that tells it you want to connect to another modem. The modem offers two ways to do this. The first method lets you call a remote modem that is set to auto answer. It is to be used in situations where you will not talk to a person before the modems connect. When you have a choice, we recommend simply using the modem to dial the number, instead of using this method. If you need to use this method, follow these steps: 1. Type the following but do not press the .carriage return: AT X3 D 2. Dial the number yourself on the telephone. 3. When you hear a carrier, press the carriage return [CR]. Your modem will try to connect with the remote modem. The second method lets you talk to someone on the phone and then connect modems without hanging up. To do this, follow these steps: 1. Talk to each other using .telephones plugged into the PHONE jacks on the backs of your modems. 2. When you're done talking and you're ready to start using the modems, DO NOT hang up your telephone receivers. 3. One of you: Type ATA [CR]. The other one of you: Type AT X3 D [CR]. You'll both hear a high- pitched squeal from your modem speakers (if they're turned on). Then you should both see a .CONNECT result code appear on your screens. 4. Hang up your phone receiver, and you are online. When you're done, hang up the modems through your software or by issuing the escape code (+++), followed by the AT H command. STORING A TELEPHONE NUMBER You can store up to 4 frequently called phone numbers in your modem's memory by using the &Zx=n command, where x is the modem's memory location and n is the number to store (which cannot exceed 36 characters). The value in x can be 0, 1, 2, or 3, with x=0 the default. For example, this saves tone-dialed number T555-9624 in location 1: AT &Z1=T555-9624 [CR] DIALING A STORED NUMBER To dial a stored number, use D with the Sx modifier. This command dials the number stored in memory location x. For example, the following command dials the number in memory location 1: AT DS1 [CR] AUTOMATIC PULSE DIALING IF TELEPHONE SYSTEM DOES NOT SUPPORT TOUCH TONES If your local telephone system does not support touch-tone dialing, the way your modem acts depends on how it is configured. If your dial string includes the P dial command modifier OR you have previously issued the P command, the modem will pulse dial. If your dial string includes the T dial command modifier OR you have previously issued the T command, the modem will tone dial. If your dial string does not include a P or T dial command modifier AND you have previously issued the T command, the modem will do the following: 1. Listen for dial tone. (Note that changing the X command from its default can affect this step.) 2. Tone dial the first digit in the dial string. 3. Wait up to 3 seconds for the dial tone to end. 4. If the dial tone ends, the modem continues dialing. If the dial tone does not end, the modem knows your phone system can only handle pulse dialing (because the phone system did not process the tone-dialed first digit). So it switches to pulse mode, pulse dials the first digit, and then pulse dials the rest of the number. Note that this feature can cause problems with PBX systems -_ for example, systems where a 9 is dialed to get a dial tone outside a company's in-house phone system. Such systems deliver a second dial tone after receiving the first digit. DISABLING CALL WAITING If you have "call waiting," we recommend that you disable it before using your modem. If you don't disable it and a call comes in while you are online, you will either lose data or be disconnected. Please refer to your local telephone book or phone company for directions on how to do this. In many locations, you can disable call waiting by placing *71 or *70 in the dial string, either just before or after the number you are dialing. For example, you might use: AT DT *71 555-0000 [CR] Call waiting usually resumes immediately after you hang up, so you will have to do this on each call. If your software has a built-in dialing prefix (or macro) you can probably include this code so it is used on every call ******************************************************************************** CHAPTER 5: ANSWERING ******************************************************************************** Your modem can answer telephone calls and (with help from your telecom munications or fax software) manage those calls appropriately. Under certain conditions, the modem can also tell you who is calling, before the call is answered. Your fax and telecom software should be able to handle most answering tasks. However, because some of the modem's capabilities are relatively new, a thorough understanding of the answering process will help you set up your software and modem for optimal performance. This chapter is designed to give you that understanding as well as to explain the basic techniques for answering incoming telephone calls. (For more information on your software, refer to your software manuals.) ANSWERING CALLS Your modem provides three ways to answer calls: * You issue the A command when you detect an incoming call. This makes the modem answer the call immediately. The modem will go online when it detects a carrier. * You talk on a phone and then connect modems. This is described in Chapter 4, "Dialing From a Telephone." * You set your modem to "auto answer." In this case, your modem automatically answers all incoming calls. The rest of this section explains how to use auto answer. Your modem answers calls automatically (auto answer) if you set register S0 to a value from 1 to 255. This value is the number of rings the modem will wait before it answers the call. The following example sets the modem to answer calls after the second ring: AT S0=2 [CR] If you set the modem to auto answer and your modem shares a line with a telephone, the modem may answer calls before you can intercept it. Be careful with auto answer unless you have a dedicated modem phone line. By default, auto answer is disabled. On some modem models, if you set the modem to auto answer, the modem displays the AA message unless the modem detects a ring signal. Then when the modem does detect a ring, the RI message is displayed for 2 seconds. If you plan to connect your modem directly to a mainframe or minicomputer where it will be .dedicated to auto answer operation, you might need to change the modem's configuration from its defaults. Because every situation is different, it's hard to say what you'll need to change. First try the Q1 command. If Q1 doesn't solve the problem, also try .&D, and if there's still a problem, also try &C. Please call Technical Support if you need assistance. If you plan to use your modem to run a Bulletin Board System (BBS), the BBS software should automatically configure it for auto answer operation. If you think that you need to change it, refer to your BBS software manual or contact the BBS software publisher for details on how your modem should be set. IDENTIFYING THE SOURCE OF AN INCOMING CALL (CALLER ID) Caller ID is a way for you to find out who is calling before you answer a telephone call. In between the first and the second ring of an incoming call, the phone company sends information such as: * the date and time of the call * the phone number from which the call originated * possibly a name associated with that phone number The information displayed will vary depending on your phone company and your software. Caller ID (optional feature #141) is not available on all modem models. The I10 command reports which optional features your modem supports. Potential Applications Caller ID can be used by many computer applications for improved security, efficiency, and convenience. Here are a few of the potential applications: * Bulletin Board Systems (BBSs). A BBS can positively identify callers without the normal tedious logon sequences, and prevent unauthorized entry due to lost or stolen accounts and passwords. * Screening Calls. Your computer can display the number and possibly name of who is calling, so you can decide if you want to answer or not. * Professional billing. Your computer can match incoming calls to your client list and automatically create a charge to the client's account for your phone time. * Database Lookup. Your customer's record or account can be displayed on your computer screen before you answer the call. Your ability to take advantage of these applications (and others) depends on your software. Can You Use Caller ID? To use the modem's Caller ID feature: * Your local telephone company must provide Caller ID, and it must be enabled for your telephone line. At present, Caller ID is only available in some areas of the country. If your phone company does not offer Caller ID, you cannot use your modem's Caller ID feature. To find out if Caller ID is available in your area, contact your local telephone company. * You must have software that allows you to use Caller ID. The "Software Options" section explains software requirements. * Your modem's Caller ID feature must be turned on. The "Caller ID AT Commands" section in this chapter provides more information. Software Options The degree to which you can take advantage of Caller ID depends on your software: * Incoming Data Calls At present, most people use telecommunications software to take advantage of Caller ID. If configured to do so, when the modem receives an incoming call, it displays the call information in the telecom software's terminal mode screen. After reading the information displayed in your telecom software, you can either let your modem answer the call or you can answer the call yourself using a telephone handset. The "How to Use Caller ID with Telecommunications Software" section in this chapter provides more information. * Incoming Fax Calls To use the Caller ID feature with incoming fax calls, your fax software must support Caller ID. If your fax software does, refer to your fax software manual to learn how to use this feature. * Additional Applications Many widely used BBS programs now support Caller ID. Caller ID AT Commands The following AT commands enable and disable Caller ID: #CID=0 Disables Caller ID. #CID=1 Enables Caller ID in formatted format. #CID=2 Enables Caller ID in unformatted format (ASCII printable hex numbers). How to use Caller ID with Telecommunications Software As with any AT data commands, you can issue the Caller ID commands from your telecommunications software terminal mode, or include them in your telecom software's initialization string. Other software that supports Caller ID will probably issue these commands automatically. The following steps explain how to use telecommunications software to take advantage of Caller ID. 1. Read the "Can You Use Caller ID?" section earlier in this chapter. 2. Start your telecommunications software and make sure it is in terminal mode. 3. Configure your modem for Caller ID by typing the following commands in your software's terminal mode. As an alternative, you can include the commands in your telecom software's init string. [CR] represents a carriage return. a. Enable the modem's Caller ID feature. AT #CID=1 [CR] b. Make sure no other devices (such as your modem, answering machine, or fax machine) answer before the second ring. For example, you can set your modem to answer on the third or later ring, as shown below. (The phone company sends the Caller ID information between the first and second ring of an incoming call.) AT S0=3 [CR] c. If you want to skip step 3 in the future, issue the following command to save the above commands in your modem's nonvolatile memory. AT &W0 [CR] 4. Now the modem is ready to receive an incoming call. When a call comes in, the telecom software's terminal mode screen will reflect the modem's activity. It will look something like this: RING DATE = 0321 TIME = 1405 NMBR = 5039672400 NAME = ANYCOMPANY RING Here is an explanation of this display: * The first RING result code appears when the modem receives the first ring signal (equivalent to a telephone ringing once). * The next four lines represent the Caller ID information, which the phone company sends in between the first and second ring of an incoming call. * The actual information displayed will vary depending on your phone company. For example, the date and time may be displayed in different locations, and the "name" might not be included. Also, some extraneous characters might be included. For example, several customers have told us that in parts of Canada, in place of single spaces the number "30" is displayed. * The second RING result code represents the second ring signal the modem receives. 5. If you recognize the phone number or name displayed in step 4, you may be able to determine if the call is voice or data. 6. Now do one of the following: * If the call is from a person (a "voice call"), pick up the telephone handset and answer the call yourself. * If the call is from another modem (a "data call"), let your modem answer the call automatically. If the modem answers the call, you will then see a CONNECT result code (or whatever message your software displays upon receiving a CONNECT result code). DISTINGUISHING BETWEEN INCOMING VOICE, FAX, AND DATA CALLS (SILENT ANSWER AND ADAPTIVE ANSWER) Your modem can determine if an incoming call is fax or data, or if an incoming call is fax or voice (if your modem supports Silent Answer). At this time, it cannot distinguish between incoming fax, voice, and data calls. When a call comes in, your modem knows if the call is a fax because it detects fax tones from the sending fax machine. But if the modem does not detect fax tones, it can only do one of the following: * assume the call is a voice call (Silent Answer) and allow you or your answering machine to take the call * assume the call is a data call (Adaptive Answer), send a data carrier, and wait for the remote modem to try to connect If the remote modem does not detect fax tones, it knows the incoming call is either voice or data. But there is no way to determine which it is (voice or data). To understand why, think for a minute about when you make a data call to a remote modem. Your modem dials and then waits for a "data carrier" to be sent from the remote modem (the answering modem). Data carriers are generated only by an answering modem. So when your modem answers an incoming call and tries to determine whether it is voice or data, it "hears" nothing it recognizes _- since the modem originating a data call does not generate a carrier. So it must assume either that the call is a data call (and send a data carrier) or a voice call (and remain silent). By choosing either Silent Answer or Adaptive Answer, you tell the modem whether to treat non-fax calls as voice calls or data calls. It is possible to switch back and forth between Silent Answer and Adaptive Answer, but they cannot both function at the same time. SILENT ANSWER Silent Answer (optional feature #141) is not available on all modem models. The I10 command reports which optional features your modem supports. What is Silent Answer? With Silent Answer, when a call comes in, the modem lets another device _- an answering machine, or a person using a telephone -_ answer the incoming call. As soon as an answering machine or person answers the call, the modem silently "listens" to the sound coming over the line. Then: * If the modem detects fax "CNG" tones, it attempts a fax connection. * If the modem does not detect fax tones, it does nothing, allowing you or your answering machine to continue handling the call. The following is what happens when Silent Answer is enabled and the modem receives an incoming call. 1. An incoming call causes a ring signal to come across the telephone line. 2. The answering machine (or a person) answers the call. This assumes your answering machine is set to answer an incoming call on fewer rings than the modem. (For example, the answering machine is set to answer on the third ring, and the modem is set to answer on the fourth ring.) It is preferable for the answering machine to answer on the third ring and the modem to answer on the fourth (or fifth if you are having difficulty receiving) ring. 3. If the modem detects fax "CNG" tones, the modem, fax software, and computer handle the fax call. 4. If the incoming call is NOT a fax call (incoming call is a voice or data call): a. Silent Answer does not detect fax "CNG" tones, so it knows the call is not a fax call. b. Silent Answer does not detect data carrier tones, even if the call is a data call. This is because when data connections are attempted, the data carrier tones are generated by the answering modem, not the originating modem. c. Because Silent Answer does not detect data carrier tones, Silent Answer assumes the call is not a data call. d. Because Silent Answer thinks the call is neither fax nor data (incoming call is a voice call), the modem does not go off hook. e. Answering machine handles the call. The implementation of Silent Answer depends on your software. Silent Answer is a proprietary feature and is not available on all varieties of modems. Do You Need to Use Silent Answer? The primary benefit of Silent Answer is that it lets your modem distinguish between incoming fax and voice calls when both the faxmodem and an answering machine (or telephone) are connected to the same telephone line. This eliminates the need for dedicated fax and voice lines. Can You Use Silent Answer? To use Silent Answer: * Your modem must support Silent Answer * Your fax software must support Silent Answer. * Your modem and answering machine must NOT be "daisy-chained." In other words, do not plug the answering machine into the back of the modem, and do not plug the modem into the back of the answering machine. Instead: - Plug the answering machine and modem into different wall jacks (e.g., jacks in different rooms). - If both devices are to be connected to one telephone wall jack, use a "Y jack" at the outlet, and plug each device into the Y jack. * Your answering machine tape must be "blank" for the first 3 seconds before the message. This allows the fax CNG tones to get through. * If you have an older answering machine that does NOT automatically turn itself off when it detects that a person or the modem has answered the call, you need a $7.95 adapter from Radio Shack, part #43-107. This adapter disconnects the answering machine from the phone line when the call is answered. It goes between the answering machine and the wall jack. Make sure the modem is not connected after the adapter. ADAPTIVE ANSWER What is Adaptive Answer? Adaptive Answer lets your modem determine if an incoming call is fax or data and handle the call appropriately. With Adaptive Answer ENABLED, and Silent Answer disabled, the following is what happens when the modem receives an incoming call. 1. An incoming call causes a ring signal to come across the telephone line. 2. The modem answers the call. 3. If the modem detects fax "CNG" tones, the modem, fax software, and computer handle the fax call. 4. If the modem does not detect fax tones, it assumes the call is a data call. It sends a data carrier and waits for the remote modem to try to connect. 5. If a remote modem responds, the modems try to connect. 6. If no remote modem responds, the modem hangs up. The implementation of Adaptive Answer depends on your software. If Silent Answer and Adaptive Answer are both ENABLED, Silent Answer takes precedence. Can You Use Adaptive Answer? To use Adaptive Answer, your fax software must support it. Please consult your fax software manual booklet to determine if your software supports Adaptive Answer. If your fax software does not support Adaptive Answer, please refer to the section below, "Software That Does Not Support Silent Answer/Adaptive Answer." SOFTWARE ISSUES Software That Supports Silent Answer/Adaptive Answer If your fax software DOES support Silent Answer or Adaptive Answer, please refer to the fax software manuals for specific instructions on using it. Software That Does Not Support Silent Answer/Adaptive Answer If your fax software does not support Silent Answer or Adaptive Answer, please contact the software company to obtain a version of your software that does support these features. Software vendors are being encouraged to add support for Silent Answer and Adaptive Answer to their software. If your fax software does not support Silent Answer or Adaptive Answer, you might be able to modify your fax software initialization string, or in some other way modify your fax software, to use these features. ******************************************************************************** CHAPTER 6: CONNECTING ******************************************************************************** A connection begins after one modem answers a call from another modem, and ends when either modem disconnects. Because of "negotiation," the process of making a connection might take several seconds after dialing. Chapter 3 explains negotiation. BELL & CCITT PROTOCOLS Your modem supports the following communications protocols: Bell 103, Bell 212A, .CCITT V.21, CCITT V.22, CCITT V.22bis, CCITT V.32, and CCITT V.32bis (optional feature #140). These protocols define the basic communications link between the two modems _- that is, the frequency of the tones they use and how they modulate the data. These protocols are completely separate from the error correction and data compression protocols. The exact protocols that you will use are determined by the type of modem you are connecting to. For 300 bps and 1200 bps connections, there is one set of protocols used in the U.S. and Canada and another used in most of the rest of the world. The U.S. protocols are Bell 103 (300 bps) and Bell 212A (1200 bps) -_ named after the AT&T Bell Labs that developed them. For Europe, and much of the rest of the world, the protocols adopted by the CCITT (an international standards committee) are used: V.21 (300 bps), and V.22 (1200 bps). You will probably only use one set of these protocols, unless you make international calls. At 2400 bps and faster connections, CCITT protocols are used everywhere: V.22bis (2400 bps), V.32 (4800/9600 bps), and V.32bis (7200/9600/12,000/14,400 bps) CONNECTION RATES Chapter 3 explains how error correction and data compression affect connection rates. CONNECTION TYPES The following connections are possible between two modems like yours. Chapter 3 provides more information: ORIGINATING MODEM CALLS AT: --------------------------------------------------------- | NORMAL \N | DIRECT \N | RELIABLE | AUTO- | RELIABLE | | | \N2 | RELIABLE | \N4 | | | | \N3 | ------------|-----------|-----------|----------|-----------|--------- ANSWERING | NORMAL \N | Normal | Direct | hangs up | Normal | Hangs up MODEM SET | | | or Normal | | | TO: |-----------|-----------|-----------|----------|-----------|--------- | DIRECT \N | Normal | Direct | hangs up | Normal | hangs up | | or Direct | | | or Direct | |-----------|-----------|-----------|----------|-----------|--------- | RELIABLE | hangs up | hangs up | MNP | MNP | MNP | \N2 | | | | | |-----------|-----------|-----------|----------|-----------|--------- | AUTO-\N3 | Normal | Direct | MNP | LAPM or | LAPM or | RELIABLE | | or Normal | | MNP | MNP |-----------|-----------|-----------|----------|-----------|--------- | RELIABLE | hangs up | hangs up | MNP | LAPM or | LAPM or | \N4 | | | | MNP | MNP --------------------------------------------------------------------- All Normal and Reliable connections also take advantage of flow control, which allows your computer and modem rates to be different. With Direct connections, these rates must be the same. You can only use data compression if you have made an error correcting (MNP or LAPM) connection with another modem that supports data compression. MNP 5 is only used with MNP error correction, and BTLZ is only used with LAPM error correction. If a data compression connection cannot be made, or if %C0 or %M0 have been used to disable data compression, only error correction will be attempted. ******************************************************************************** CHAPTER 7: CREATING CUSTOM MODEM CONFIGURATIONS ******************************************************************************** DO YOU NEED TO CONFIGURE YOUR MODEM? Before your modem left the factory, it was set up to act a certain way; for example, it returns full-word result codes and waits for a dial tone before dialing. These settings will work for most situations, but in some circumstances, you may need to change your modem's default configuration _- like if you want to change the speaker volume setting. This chapter tells how to do that. FACTORY DEFAULT, ACTIVE, & STORED CONFIGURATIONS There are three types of modem configurations: * The "factory default configuration" is stored in the modem's permanent memory (called firmware ROM). There are 3 different factory configurations, depending on what kind of computer you are using and if you need error correction and data compression. * The "active configuration" is the configuration you're using when you have your modem turned on. It is stored in the modem's temporary memory (called temporary RAM). * If you save the active configuration, it becomes a "stored configuration" that resides in the modem's nonvolatile RAM ("novram"). Whenever you turn on your modem, it loads a stored configuration from nonvolatile memory into the active configuration area. If you don't save your active configuration, it will be lost when you turn the modem off. CREATING A CUSTOM CONFIGURATION You can create a custom configuration by changing the settings that comprise the active configuration. The modem's AT commands let you change most of these settings by issuing single commands. Occasionally, you may need to change a setting by issuing the Sr=n command, which changes low-level S registers. AT Commands Used When Creating a Custom Configuration You can use a number of different AT commands to change settings, including the following commands, which are particularly useful. Be sure you understand Chapter 2 before using AT commands. Appendix B explains AT commands in detail. * &F0, &F,1 and &F2, which reset the active configuration to preset factory default configurations. * &V, or \S (optional feature #146), which display configurations. The I10 command reports which optional features your modem supports. * &Wn (where n is profile 0 or 1), which saves your active configuration in the modem's nonvolatile RAM. * Zn (where n is profile 0 or 1), which resets the modem and loads the stored configuration from profile 0 or 1. * &Y1, which causes the stored configuration from profile 1 to be loaded into the active configuration area when you turn on or reset your modem. If you do not issue &Y1, the configuration from profile 0 is loaded instead. AT Commands for Changing S Registers Directly Sr? displays the value in register r. For example, ATS0? reads S register 0 and displays three digits -_ 005 if the value is 5. Appendix D describes your modem's S registers. Sr=n sets the value in S register r to n. The n must be a decimal integer from 0 to 255. For example, the command ATS0=4 [CR] sets register S0 to 4, which causes the modem to automatically answer all incoming calls after the fourth ring. The modem replies with OK. Note: If you have a choice, it is usually easier to use the AT commands to change S registers indirectly, instead of using Sr=n. &F, &F1, &F2: THE FACTORY CONFIGURATIONS The following commands load the factory default configurations: &F Load basic 9600 or 14,400 bps configuration, with error correction and data compression disabled. This command includes these settings: \N1 &K0 &Q0 &D2. Use this configuration if your telecom software or modem cable does not support hardware handshaking (regardless of your computer type). In this case, you will not be able to use data compression or error correction. &F1 Load Macintosh error correction/data compression configuration. This command includes these settings: \N3 &K3 &Q5 &D0. This is the configuration needed by most Macintosh computers, except those using either telecom software that does not support hardware handshaking or a modem cable that does not support hardware handshaking. &F2 Load IBM (and others) error correction/data compression configuration. This command includes these settings: \N3 &K3 &Q5 &D2. This is the configuration needed by most computers, except Macintosh computers and any computer using either software or cable that does not support hardware handshaking. The settings included with &F1 and &F2 do the following: \N3 AutoReliable connection. Makes the fastest possible connection and uses the best possible error correction and data compression. &K3 RTS/CTS hardware flow control. Allows you to use data compression and error correction. &Q5 Asynchronous error correction mode. &D0, &D2 Selects correct DTR settings so hardware handshaking flow control will work. ******************************************************************************** CHAPTER 8: SOLVING PROBLEMS ******************************************************************************** The first half of this chapter -_ "Part 1: Symptoms, Sources, & Solutions" -_ should help you solve most telecommunications problems. For numerous problems, Part 1 provides: * symptoms exhibited * possible sources of the problem * potential solutions The second half of this chapter -_ "Part 2: Additional Troubleshooting Information" -_ provides more detailed information in three categories: High Speed Communication, Line Noise, and Miscellaneous. PART 1: SYMPTOMS, SOURCES, & SOLUTIONS To use Part 1: 1. Try the suggestions in "First, Double Check Your Equipment & Configuration." 2. Scan the headings and bullets (*) in the rest of this section until you find the bullet that lists the symptoms of the problem you are having. The potential problems are divided into three sections: * problems encountered while offline * problems when trying to connect * problems while connected 3. Note the potential sources. 4. Try the solutions that seem most appropriate. If you're not sure, try each suggestion in order. First, Double Check Your Equipment & Configuration Before doing anything else, try completely disconnecting and then reconnecting the modem as explained in the Getting Started manual. (For your modem and many other electronic products, this solves common problems that are caused by incomplete connections.) Also try using &F0, &F1, and &F2 to return the modem to one of the factory default configurations (as explained in Chapter 7). This may fix problems caused while trying to re-configure the modem. If you continue to have problems, try using the potential solutions given in the rest of this chapter. Problems Encountered While Offline The Getting Started manual provides additional information. * If you have an external modem and the modem appears not to have power, make sure you are using the power adapter that came with your modem (9 VAC) and that the modem is plugged into a working power outlet. If this is OK, press the ON/OFF button once or twice. If the modem still does not have power, disconnect it from your computer and press the ON/OFF button once or twice again. If the modem turns on, the problem is with your computer's serial port or your RS-232C cable; contact your computer dealer for assistance. If the modem does not turn on, the problem is with the modem or power supply; call Technical Support for assistance. * If your computer is not sending data to your modem, as determined with the SD light on some modem models, one of the following is probably the reason. - The modem and computer are not connected properly. Check the connections, and make sure the RS-232C cable is plugged into the correct computer port. Also make sure that the data is going to the correct serial port. Your computer may have other serial ports for your printer, mouse, etc.; some software requires that you tell it which serial port you're using. - The RS-232C cable is damaged or the wrong type for your computer. Get a working cable from your dealer. - Your computer's serial port is not working properly. Contact your local computer dealer for assistance. - Your software is not working properly. Refer to your software manual for assistance. - Your modem is not working properly. Contact Technical Support for assistance. * If you have an .IBM PC or compatible and your software does not recognize the modem, one of the following is probably the problem: - You have more than one piece of hardware assigned to the same COM port. Make sure only one device is assigned to each COM port. - The COM port selected in your software is different than the COM port selected on the modem board (internal modems only). Make sure the COM port selected in your software is the same as the COM port selected on the modem board. The Getting Started manual provides more information. * If what you type does not appear on the screen, enable command echo by issuing the E1 command; then issue the &W command. Alternatively, you may be able to turn on Local Echo in your software. * If two letters appear on the screen for every one you type while in the command state, disable command echo by issuing the E command. You can also solve this problem by using your telecommunications software to change your computer setting to full duplex operation. * If you type AT .followed by a carriage return and the modem does not acknowledge it with the OK result code, one of the following may be the problem. - You are not in the command state. Enter the .escape code (+++) to switch from online state to command state. - Your computer is set to a rate other than 300, 1200, 2400, 4800, 9600, 19,200, 38,400, or 57,600. Use your software to change your computer rate to one of these rates. - Result codes may be disabled. Issue the Q or &F command, and then issue the .&W command. - Your computer's .serial port is not working properly. Contact your local computer dealer for assistance. * If you type AT .followed by a carriage return and the modem returns a 0, your modem is set to use numeric result codes instead of verbose result codes. Issue &F, &F1, or &F2, or issue V1 and then &W. Problems When Trying to Connect Chapters 4, 5, and 6 provide additional information on dialing, answering, and connecting, respectively. * If you cannot get your modem to dial, you probably have the telephone line plugged into the wrong jack. Make sure that your telephone line is plugged into LINE and your (optional) telephone is plugged into PHONE. As an alternative, you may also want to try unplugging any other phone devices connected to your phone line. * If you are having trouble connecting and you suspect the remote modem might be causing the problem, read the section called "Compatibility With Other Modems/Older Modems" later in this chapter. * If you can get a dial tone but can't connect, you may not have the correct power supply. See the "Power Supplies" section later in this chapter. * If you can send AT commands to your modem (you'll see the OK result code after typing AT [CR]) but you can't get a dial tone, you may not have the correct power supply. See the "Power Supplies" section later in this chapter. * If you can only connect when the modem volume is low, you may not have the correct power supply. See the "Power Supplies" section later in this chapter. * If you are having trouble making a Reliable connection, one of the following may be the problem: - Your modem is not set to make a Reliable connection. Issue &F1 (Mac) or &F2 (IBM), or issue \N2, \N3, or \N4. Chapter 7 provides more information on these commands. - The remote modem does not support MNP or V.42. A Reliable connection is not possible in this case. - The remote modem supports MNP or V.42, but it is not in Reliable mode. Have the remote modem operator change to Reliable mode. - The remote modem supports MNP or .V.42 and either gets confused by the length of time your modem takes to "negotiate" the connection or confuses negotiation characters with the remote computer's log-in sequence. In this case, try using \N (Normal) to disable error correction and data compression and then try it again. - The telephone line is so poor and noisy that it interferes with the negotiation process. A variety of factors can cause line noise. Refer to the "Line Noise" section later in this chapter to determine the source of the problem. You can also try to make a Normal connection instead. * If your modem is not recognizing busy signals, or if your modem is interpreting other signals from the remote location as busy signals, please contact Technical Support for assistance. * If you cannot connect and none of the other issues listed here seem to be the problem, refer to the "Line Noise" section later in this chapter. Problems While Connected Chapter 6 provides additional information on modem connections. * If you have connected to a remote modem but your computer has frozen up or all you see on your screen are garbage characters, one of the following may be the problem: - If you are using a .Macintosh and flow control, you may have the wrong cable. Refer to Chapter 3. - Line noise could be causing the problem. Refer to the "Line Noise" section later in this chapter. - You have made a Direct connection, and your computer and modem are using different rates because the modem connected at a different rate than it was originally set to. Use your software to change the computer rate so it matches the connection rate given in the CONNECT result code. - Your computer and the remote modem are set to different data bits (word length), parity, and number of stop bits. The most common are 8 data bits (8-bit word length), no parity, and 1 stop bit (8, none, 1). Change these settings in your software. - You have selected hardware or software flow control on the modem (using &K1, &K2, &K3, &F1, or &F2), but not in your software. Both your hardware and software must be set to use the same type of flow control. If your software does not let you turn flow control on and off, it either handles flow control automatically, or it does not support flow control. If your software does not support flow control, you probably cannot use Reliable or Normal connections. In this case, either obtain software that supports flow control, or disable flow control by issuing the &K0 command. - Your modem cable is not working properly or does not support hardware handshaking. Refer to the "Flow Control & Hardware Handshaking Cables on External Modems" section later in this chapter. - Your computer's serial port is not working properly. Contact your local computer dealer for assistance. - Your modem is not working properly. Contact Technical Support for assistance. - You are using the Bell 103 (300 bps) protocol to make a 300 bps connection with one or both of the modems set to 1200 or 2400 bps. See Chapter 6 for information on how to do this. * If your online communication is very slow and you are using error correction (and the TE or RE message is displayed on modems that support these messages), it may be that you are getting lots of transmission errors on a very noisy phone line (with lots of static, like you can hear on a voice phone sometimes). In this case, the modem has to continually resend data, slowing your actual throughput. To solve this problem, try hanging up and reconnecting. Refer to the "High Speed Communication Problems" section later in this chapter. * If you can connect but then can't communicate with the remote modem, line noise could be causing the problem. Refer to the "Line Noise" section later in this chapter. * If you can connect but then the modems disconnect for no apparent reason, line noise could be causing the problem. Refer to the "Line Noise" section later in this chapter. * If you can connect but then the modem speed drops unexpectedly, line noise could be causing the problem. Refer to the "Line Noise" section later in this chapter. * If you are using a Macintosh and, when transferring data, the modem suddenly disconnects from the remote computer and displays the OK result code, issue AT&F1 [CR] and then get back online and try your transfer again. If you still have trouble, one of the following could be causing the problem: - Line noise. Refer to the "Line Noise" section later in this chapter. - Wrong modem cable, especially on a Macintosh. Refer to the "Flow Control & Hardware Handshaking Cables on External Modems" section later in this chapter. * If your transfer rate when downloading seems slow, try the following: - If your software protocol (Ymodem, Kermit, etc.) shows many blocks being resent and the Receive Error (RE) message is never displayed (on modems that support this message), you are probably losing data between the modem and computer -_ not the phone lines. Since the files you are transferring are probably pre-compressed, it will be best to set your computer rate close to the connection rate. We recommend 19,200 bps for most 9600 and 14,400 bps connections. The section "Slow Downloads" later in this chapter provides more information. - If you are losing data when using Zmodem for file transfers, it is probably because data comes to the computer too fast for the computer's serial port to keep up with. To solve this problem, use your software to reduce your computer rate (as described in the previous paragraph), use a different transfer protocol, or use software flow control. The section "Flow Control & Hardware Handshaking Cables on External Modems" later in this chapter and the following steps explain how to use flow control: 1. Use your software to turn ON hardware (RTS/CTS) flow control. This should automatically turn OFF software (XON/XOFF) flow control, but you may need to use your software to manually turn off software (XON/XOFF) flow control. 2. Issue the &K4 command to turn ON software flow control in the modem. 3. Issue the &W command to save the setting. * If your software locks up during a file transfer or large data transfer, and you are using hardware .flow control (&K3), one of the following may be the problem (also see the section "Flow Control & Hardware Handshaking Cables on External Modems" later in this chapter): - Flow control is turned off in your software. Use your software to turn flow control (or hardware handshaking) on. - Your modem cable does not support flow control. Use the cable that may have been provided with your modem and/or refer to Chapter 3. - Data is coming into the computer faster than it can accept it. For more information, refer to Chapter 3 and the "Serial Port Speed Problems" section later in this chapter. * If your software locks up during a file transfer or large data transfer, and you are using XON/XOFF software flow control (&K4), you may be trying to transfer binary data. Some data may include the special XON and XOFF characters _- thereby confusing the modem. Disable XON/XOFF flow control. The descriptions of the &K command in Appendix B provide information on your options. * If you are losing characters or data due to the buffer overflowing, the section "Faster UART Chip for PC Compatibles used with External Modems" later in this chapter explains some causes and solutions. * If you enter the escape code (+++) but the modem does not acknowledge it by sending the OK result code, one of the following may be the problem.. - You issued the plus signs (+) too quickly. Wait two seconds after sending any characters before sending the escape code, then send the escape code, and then wait two more seconds. - Your computer rate is different than the connection rate with a Direct connection. Use your software to change your computer rate. - The escape code character has been changed in register S2 from a plus sign (+) to something else. Change the escape code character back to a `+' or use the character in S2. * If you cannot get your software to hang up, issue the escape code (+++) followed by the H command. (If this doesn't work, you can turn the modem off to make it hang up, but this isn't a good long-term solution.) After your software hangs up, so that it won't happen in the future, check your software to see if it uses DTR or +++ to hang up. (If you use a Macintosh, your software probably uses +++) Then do one of the following: - If your software uses DTR to hang up, issue &D2 followed by &W. - If your software uses +++ to hang up, increase the length of time between the +++. and the ATH in your software. Most software uses tildes (~) to lengthen time; if yours does, add two or three more tildes to increase the timing. - If these suggestions don't solve the problem, read your software manual to learn what your software needs to hang up properly. * If you have changed your modem configuration and can't get your modem to work properly, try resetting it to the factory settings &F1 or &F2 and reread Chapter 7. PART 2: ADDITIONAL TROUBLESHOOTING INFORMATION The rest of this chapter provides more detailed information in three categories: High Speed Communication, Line Noise, and Miscellaneous. HIGH SPEED COMMUNICATION PROBLEMS Serial Port Speed Problems Many computers have not been designed for the high-speed performance requirements of your modem. The main problem encountered will be data coming into the computer faster than it can accept it, resulting in lost data. Hardware handshaking takes care of some of this, but sometimes the computer is so tied up with another process that it can't even do handshaking. With data coming in at speeds up to 57,600 bps, the computer must be very attentive to the serial port. The rest of this section describes some things to watch for and some possible fixes. For more information on computer rate, connection rate, error correction, and data compression, including definitions of these terms, refer to Chapter 3. Faster UART Chip for PC Compatibles Used with External Modems Most older and some newer PCs use the 16450 UART chip for serial communications. This chip was not designed for today's high speeds and has a limited memory capacity which simply cannot keep up with faster PCs and transmission speeds. If your existing chip is socketed, you can replace this chip with the 16550 UART (which has a 16-byte buffer more suitable for high-speed transfer). In some cases, it may be easier for you to add a new serial card with a UART to your system. This may solve most lost character situations. If a 16550 UART is not an option for you and your computer is too slow (indicated by lost data due to the buffer overflowing), use your software to set your computer to a slower rate (such as 19,200 or 9600). For instance, some laptops do not have a 16550 UART, and may require the computer rate to be set slower than the connection rate. Slow Downloads If you download files from a BBS or online service, you should expect CPS (character per second) rate about 1/10th of your connection rate; i.e. 9600 bps = 960 cps, 14,400 bps = 1440 cps. This is because it takes 10 bits to transmit each character. If you turn on V.42bis compression and download an uncompressed file, the speed may be 2-4 times as fast. However, most files will be already compressed and you will not see this improvement. But even on pre-compressed files, with V.42bis you should always see about an 18% improvement due to efficiencies in the protocol. Now a 9600 bps connection yields about 1000 cps and a 14,400 bps connection yields about 1600 cps. However, this is in an ideal situation. In the real world you will find that there are many factors that can slow transfer speeds. Your computer or software may not keep up. Slow disk drives on either end can slow it down. The remote system may have many users on it, slowing it down. (You may find that your best download speeds on many services are late at night when few users are on the service.) And some services are notorious for slow downloads in general. A download of 600 - 800 cps on a CompuServe 9600 bps line is a very normal occurrence. For more information on this topic, refer to Chapter 3. Multitasking Multitasking computers allow you to do many different things while other operations take place in the background. Although you don't see them in progress, background operations can be complex and can sometimes demand too much of your computer's attention to allow high-speed communications. High-speed transmissions are more reliable in a single-user situation with as few applications as possible in use. This section lists some specifics which can interfere with high-speed communications, depending on your platform. Amiga Amiga Workbench 2.x allows transmission rates about 100% faster than Workbench 1.3, which limits you to 9600 bps reliably. Background tasks, graphics modes, SCSI interfaces and hard drives all can have an impact on the actual transmission rate. With WB 2.x, you should be able to achieve reliable serial port speeds between 9600 and 19,200 bps _ depending on CPU model and speed. Using an accelerator also helps alleviate this problem. Macintosh AppleTalk/AppleShare activity (including printing) can lower the transmission rate because this activity has a higher priority than other serial communications. Some inits may also cause problems. PCs & Compatibles Please see the "Faster UART Chip" section earlier in this chapter. 'TSR (terminate stay-resident) programs' can also slow the transmission rate. For throughput over 19,200 bps, your computer should have a 386 or faster processor. Multitasking performance varies: * Windows 3.0 will often have problems at serial port speeds (computer rates) higher than 9600 bps. * Windows 3.1 correctly supports up to 38,400 bps with a 16550 UART. * Windows NT and OS/2 should have no problems with multitasking. All Platforms - Displays If you are downloading text that is displayed on your screen as it is received, your computer's display may have problems keeping up with the speed of the incoming data. One way to get better performance is to change your display to a lower number of colors, or monochrome, so it is more efficient. All Platforms - Processor Speed Another general rule is the faster processor that your machine has, the better it will be for high-speed transfers. A 68030 or 386/486 machine will probably do better than a 68000 or 80286. Flow Control & Hardware Handshaking Cables on External Modems Hardware Handshaking Cables are ESSENTIAL To communicate at high speeds, it is CRITICAL that you use a cable with "RTS/CTS Hardware Handshaking." With error correction and data compression, the modem can often send information to the computer faster than it can accept it. When this happens, the computer tells the modem to slow down. Similarly, if data is not sent correctly to the modem and needs to be resent, the modem needs to be able to tell the computer to wait. This is called "flow control" or "handshaking" and helps to prevent data from being lost because the computer or modem was busy. Do You Have a Flow Control/Hardware Handshaking Problem? One clue to a flow control-related problem is if you are able to make a connection but nothing else happens, or if you cannot start the download/upload process. If this happens, your modem is probably configured for flow control but your cable or software does not support it. If you suspect your cable may be causing problems, use your software to set your computer rate to 2400 bps, and use the &F0 command to disable error correction and data compression. (Be sure to issue the &F0 and dial using the AT D command from your telecom software's terminal mode. If your software dials automatically, it may reinitialize the modem without your knowledge, causing problems.) If the 2400 bps/&F0 configuration solves the problem, your cable is probably at fault. If you are using a Macintosh computer and not using the cable that came with your modem, it is even more likely that your cable doesn't support hardware handshaking. The most common symptom is the modem connects, but nothing else happens. Hardware handshaking cables are wired differently for different computers. If you think you have a hardware handshaking cable but you still have cable-related problems, your cable may not be wired properly. If you need assistance, please contact your local computer dealer. Chapter 3 provides more information. Should You Use Hardware or Software Flow Control? We recommend that you enable hardware (RTS/CTS) flow control rather than software (XON/XOFF) flow control because the results are generally faster and more reliable. If you are using the Xmodem or Ymodem file transfer protocols, you must use hardware flow control. To enable hardware flow control: 1. Use a hardware handshaking cable. 2. Use your software to turn ON hardware (RTS/CTS) flow control. This should automatically turn OFF software (XON/XOFF) flow control, but you may need to use your software to manually turn off software (XON/XOFF) flow control. 3. Issue the &K3 command to turn ON hardware flow control in the modem. (This is the default.) 4. Issue the &W command to save the setting. How to Get a Hardware Handshaking Cable Your local dealer should be able to provide you with a hardware handshaking cable. When you request a new cable, be careful to specify that it needs to support hardware handshaking. If your modem came with a cable, that cable supports hardware handshaking. LINE NOISE Line noise is not a common cause of problems during fax calls. If line noise is causing problems during a fax call, one of the following will happen: * Your modem will be able to connect, but fax transmissions will be flawed (unreadable faxes, missing sections). * Your modem will connect but then disconnect unexpectedly. If you think you are having fax line noise problems, try getting a clearer connection by redialing. If that doesn't help, wait a while and try redialing again. This should solve the problem, but if necessary, and if your fax software allows it, you can also try using your fax software to set your fax transmission rate lower. Line Noise Problems on Data Calls With data calls, line noise can cause numerous problems. In general, the faster you communicate, the better your phone lines need to be. When you get up to 9600 and 14,400 bps, it is critical that you have clear lines from end to end. Line noise can cause the following problems when trying to make 9600 or 14,400 bps data connections: * No connection. * Connection, but only "garbage" characters appear on screen. * Connection, but no communication. * Connection, then disconnection for no apparent reason. * Connection, but modem speed drops. Any of these problems can occur occasionally with any speed modem. But if you are having these problems frequently, you should consider the information on line noise presented over the next few pages. Where Does the Problem Originate? Noise can be introduced at the remote site, by the phone lines, or at your local site. Before making any changes, try calling a few different remote modems, to see if you have the same line noise problems in each instance. * If you only have problems when calling one location, it is probably a problem on the remote end. * If you have problems occasionally when calling the same location it is probably a long distance connection problem. You may want to call at a different time or try a different long distance company (for example, you could try dialing the 10288 prefix to get an AT&T line). * If you have the same problems with every attempt, the cause is probably on your end. Use the following "Line Noise Checklist" to try to solve the problem. Line Noise Checklist # ACTION EXPLANATION/COMMENTS -------------------------------------------------------------------------------- 1 Determine if line noise is likely causing the | problems you're having, by reading the earlier | section, "Line Noise Problems on Data Calls." | -------------------------------------------------------------------------------- 2 Determine where the source of the line noise | problem is, as described in the earlier section,| "Where Does the Problem Originate?" | -------------------------------------------------------------------------------- 3 Make sure your modem is configured properly: | Your telecom software a. Use your telecom software to set your | manual provides more computer rate (serial rate) to 19,200 bps. | information on steps a, b, b. Use your software to turn ON hardware flow | and c. control and turn OFF software flow control. | c. Put your software in terminal mode. | d. From terminal mode, type | AT &F1 [CR] (for Macintosh) OR | [CR] represents a carriage AT &F2 [CR] (for any other computer). | return. -------------------------------------------------------------------------------- 4 Dial a number to find out if you can connect: | If you use your software to a. From your software's terminal mode, type the| dial the number, it could following. In place of number, type a | change the configuration, phone number with which you have had line | causing problems. noise problems. | AT D number [CR] | DO NOT USE YOUR SOFTWARE to DIAL the number.| -------------------------------------------------------------------------------- 5 Decide if you need to continue: | a. If step 4 solved the problem, make sure your| software configuration matches the settings | you made in step 3. | b. If you still have problems, proceed to | step 6. | -------------------------------------------------------------------------------- 6 Try to use V.32bis to connect at a low speed | and then shift up: | S110=3 causes your modem to a. Type AT S110=3 [CR]. | do several things. First, b. Repeat Step 4. | it connects at 4800 bps and c. If step 6a solved the problem, use these | negotiates error correction settings for this number. | /data compression protocols d. If not, proceed to step 7. | at 4800 bps. Then if line | quality is good, your modem | tries each successively | higher connection rate | (7200, 9600, 12,000, | 14,400), stopping at the | best possible rate for the | present line conditions. -------------------------------------------------------------------------------- 7 There is enough line noise with this number that| V.32bis cannot be used reliably. Try to connect| using V.32 instead: | S110=0 disables V.32bis a. Type AT S110=0 [CR]. | (14,400 bps), causing the b. Repeat Step 4. | modem to use the V.32 c. If step 7a solved the problem, proceed to | (9600 bps) protocol step 9. | instead. d. If not, proceed to step 8. | -------------------------------------------------------------------------------- 8 Find out if you can connect using V.32 with | S110=0 disables V.32bis, Retrain and Rate Renegotiation disabled: | enables V.32. %E0 disables a. Type AT S110=0 %E0 %G0 [CR]. | Retrain. %G0 disables Rate b. Repeat Step 4. | Renegotiation. c. If step 8a solved the problem, proceed to | step 9. | d. If not, proceed to step 10. | -------------------------------------------------------------------------------- 9 Find out if you can connect using V.32bis with | &F1 and &F2 load the Retrain and Rate Renegotiation disabled: | modem's defaults. %E0 a. Type: | disables Retrain. %G0 AT &F1 %E0 %G0 [CR] (for Mac) OR | disables Rate AT .&F2 %E0 %G0 [CR] (for other computer) | Renegotiation. b. Repeat Step 4. | c. If step 9a solved the problem, use these | settings for this number. | d. If not, proceed to step 10. | -------------------------------------------------------------------------------- 10 Disconnect other devices from the phone line: | a. Unplug all other phone devices connected to | the phone line on which you are trying to | use the modem. Make sure there are no | telephones, answering machines, modems, etc.| connected to any phone jacks on the | telephone line. | b. Repeat Step 4. | c. If step 10a solved the problem, try to | determine which device is causing the | problem. Then unplug that device and work | through this checklist again, starting at | step 3. | d. If not, proceed to step 11. | -------------------------------------------------------------------------------- 11 Try using the modem at a different location. | a. If this corrects the problem, go back to | where you have been using the modem and | having problems and proceed to the next | step. | b. Repeat Step 4. | c. If step 11a solved the problem, go to | step 12. | d. If not, the problem may be your modem. | Please contact Technical Support. | -------------------------------------------------------------------------------- 12 Briefly consider these rare causes: premise | wiring, or the need for a second telephone | line. | -------------------------------------------------------------------------------- 13 Contact Technical Support | -------------------------------------------------------------------------------- Understanding the Line Noise Checklist: Rate Renegotiation Commands & S Registers Initiating Rate Renegotiation (%G) The V.32bis (14,400 bps) specifications state that: * Your modem must be able to shift down or up in speeds (called Rate Renegotiation) when the remote modem initiates the rate change. * Optionally, your modem can initiate a rate change. Because initiating a rate change is optional, some V.32bis modems cannot initiate a rate change. Your modem CAN initiate a rate change upon changing line conditions. The %G command controls this feature. Basically, %G0 causes your modem NOT to initiate Rate Renegotiation, and %G1 DOES cause your modem to initiate Rate Renegotiation upon changing line conditions. The %G1 command is somewhat complex, and it works slightly differently on V.32 and V.32bis connections. On V.32bis connections, as line conditions change your modem will automatically initiate Rate Renegotiation. On V.32 connections, as line conditions change your modem will automatically initiate Rate Renegotiation during a Retrain. (You can also request an immediate Retrain by issuing the escape code (+++) to enter command mode, and then issuing the AT O1 command.) A Retrain lasts approximately 30 seconds and, on some models, causes the modem's RT message to be displayed. A Retrain causes your modem to: 1. Change the connection rate to 4800 bps. 2. Analyze the quality of the phone lines and optimize the connection if possible. 3. "Tell" each other which rates they support ("negotiate"). 4. If %G1 (or the other modem's equivalent) has been issued, and line conditions warrant, switch to the next possible rate both modems support, as defined by S109. By comparison, at V.32bis, %G1 causes both modems to perform only step 4, which is a much quicker way to do essentially the same thing. %G0 On V.32bis connections, as line conditions change, your modem will NOT automatically initiate a rate change (Rate Renegotiation). With &F0, %G0 is the default. %G1 On V.32bis connections, as line conditions change, your modem WILL automatically initiate Rate Renegotiation. On V.32 connections, as line conditions change your modem WILL automatically initiate a Retrain AND Rate Renegotiation, regardless of the %E0 setting (because V.32 connections require a Retrain to change rates). With &F1 and &F2, %G1 is the default. Requesting a Retrain (%E) The %E command is most useful if you want your modem to Retrain (%E1) without Rate Renegotiation (%G0) when line conditions are bad. %E0 Do not request a Retrain. Default with &F0, &F1, and &F2. %E1 Monitor line quality and automatically request a Retrain if line conditions are bad. Setting the Rate at Which Negotiations Occur (S109 & S110) Negotiation is the process where your modem and the remote modem determine what type of connection to make. The V.32bis standard negotiates the connection rate at 4800 baud, and then goes to the agreed connection rate to negotiate error correction/data compression. On noisy lines this can cause various connection problems. The solution is to set S register 110 to 3. This causes the modems to connect at the slowest possible connection rate (which is specified in S109). Then the modems can negotiate the error correction/data compression protocols without problems from noisy lines. With S110=3, as long as the line is clean enough, the modems will then upshift to the next possible connection rate. Some modems can only upshift a few times during one connection, and then they will lose the connection. The solution to this problem is to change S109 so that the modem does not need to upshift as many times if S110=3. S109 defines a range of speeds that are available on your modem. It is used when negotiating the available speeds for a connection, both when a connection is first established, and during a Retrain. Most brands of modems have S109 or a comparable register. S109 can contain the following bit values: 1 reserved 2 4800 bps 4 7200 bps 8 9600 bps 16 12000 bps 32 14400 bps 64 reserved 128 reserved S110 allows you to select V.32 or V.32bis (if your model supports V.32bis) on the modem: 0 Connect at V.32 only. 1 Enable V.32bis, disable Rate Renegotiation. 2 Enable V.32bis, enable Rate Renegotiation. Default. Same as %G1. 3 Connect at the slowest possible speed (as defined in S109), and then upshift if line quality is good. This setting only works if the modem is originating (not answering) a call. For more information on S registers, refer to Chapter 7 and Appendix D. MISCELLANEOUS TROUBLESHOOTING ISSUES What ROM Version Do You Have? Your modem's "ROM" is a set of computer chips that contain the low-level computer instructions that make the modem function. These ROM chips include standard modem capabilities provided by the ROM manufacturer. The ROM chips for some models of modems also include various enhancements that have been added to the modem, enhancements that are not available on other manufacturer's modems using the same basic ROM chips. If you need to know what ROM version you have, open your telecommunications software to terminal mode, and type one of the following commands. [CR] represents a carriage return. AT I3 [CR] This command is the letter "I" followed by the number "3." It is NOT the number "13." The modem will respond by displaying the ROM version number and related information. For example, if your modem has 1.200-H ROMs, when you issue the I3 command you will see something like this: V1.200-H TR14-Jxxx-001 053 For more information on issuing commands, refer to Chapter 2. Power Supplies It is very important that you have the proper power supply for your local AC power. The modem requires a very exact voltage and current. Using AC converters or adapters that don't meet your modem's specification can result in the modem not functioning, overheating, or ultimately failing. Simply using a converter with the U.S. 110V supply will not work adequately in most cases. The adapter that came with your modem is approved. Others may be included by your local dealer or importer and may, or may not, function correctly. Compatibility With Other Modems/Older Modems Your modem has been tested with most major brands of modems, and all of these modems work properly with the protocols your modem supports. If you cannot make a connection and you suspect the remote modem might be the source of the problem, consider the following: * The remote modem might use a proprietary protocol that we do not support. Some modems with proprietary protocols are US Robotics HST, CompuCom, Telebit, and Hayes V Series. You should be able to communicate with most of these at least at 2400 bps. Some of these modems feature "dual-standard" operation, meaning they support their proprietary standard as well as V.32 or V.32bis. However, if the remote modem's dual-standard feature has not been configured properly, you may not be able to connect at V.32 or V.32bis. * The remote modem might need a firmware upgrade if it was purchased some time ago. Several pioneers in the high-speed modem business have released upgrades to fix compatibility problems with early units. * If the remote modem is a 2400 bps modem that does not support error correction/data compression, it may not allow enough time for the "negotiation" process. Try turning off correction/compression by issuing the \N0 command. For more information about \N0 and negotiation, refer to Chapter 3. ******************************************************************************** APPENDIX A: OPTIONAL FEATURES ******************************************************************************** This appendix describes optional features supported by various modem models. To learn which optional features your modem supports, issue the I10 command from your telecom software terminal mode. This will display a list of option numbers. Optional features are listed by number below with a brief description of functionality. In many cases there is also an indication of where to look in the manual for more detailed information. 101 FAX CLASS 1 Support for Class 1 fax standard (software control of page framing protocols). See Chapter 1 for more information on fax standards. 104 FAX CLASS 2 Support for Class 2 fax standard (modem control of page framing protocols). This is a standard that was adopted by the industry prior to the official acceptance of the Class 2 standard. This standard is also commonly known by it's "proposal number" TR29.2. See Chapter 1 for more information on fax standards. 105 FAX CLASS 2.0 Support for Class 2.0 fax standard. This is the standard for modem- control of page framing as officially accepted by the CCITT. See Chapter 1 for more information on fax standards. 115 CCITT V.17, 14,400 BPS FAX Modems that include option 115 use the CCITT V.17 standard for 14,400 bps fax speeds. Faxes can be both sent and received at 14,400 bps. 120 WORLDWIDE SUPPORT This option is available for modems that are designed for international use. It enables the following three commands. %T PTT Certification Test Signals Facilitates PTT testing. *NC? Display Country Configurations Displays all country codes and configurations stored in ROM. *NCn Change Country Configuration Changes the modem's configuration for the country specified in location n. Additional Worldwide Support features are listed elsewhere in this appendix. Their feature numbers begin with "12." 121 CCITT V.23 The CCITT V.23 protocol is used for 75 bps/1200 bps communication where available. %F Data Echo Options %F1 Select 75Tx/1200Rx when &V is selected. %F2 Select 1200Rx/75Tx when &V is selected. %F3 Select V.23 half-duplex. CCITT V.23 Result Codes Your modem supports the following result codes for use with CCITT V.23. NUMERIC FORM WORD FORM 22 CONNECT 1200TX/75RX 23 CONNECT 75TX/1200RX 44 CARRIER 1200/75 45 CARRIER 75/1200 122 CCITT V.25 The CCITT V.25 protocol is an alternative option to the Hayes "AT" command set. It is used primarily in Europe. If you plan to use the V.25 commands, refer to your software manual or other source for a description of their functions. 123 BACKLISTING Enables the following commands which are used in countries that require the blacklisting standard. *B Display Blacklisted Numbers Returns a list of the blacklisted phone numbers on your modem. *D Display Delayed Numbers Returns a list of the delayed phone numbers on your modem. Blacklisting Result Codes Your modem supports the following result codes for use with blacklisting. NUMBERIC FORM WORD FORM 24 DELAYED 32 BLACKLISTED 124 ACCESS SECURITY Modems supporting Optional Feature 124 provide two methods of access security. These features prevent unauthorized users from connecting with your modem. Level 1 Access, or Password Protection, prompts for a password verification before connecting with the remote modem. Level 2 Access, or Callback Security, includes Password Protection, but does not establish a connection until it has disconnected and called back the remote modem. Both of these methods require an error-corrected transmission. Up to 20 passwords can be stored in a designated secure directory in the nonvolatile RAM, and can be added, edited and reviewed with the *Pn and *L commands. Secure access must be requested, accepted, and enabled to take effect. If enabled, secure access will stay enabled until you disable it or until the end of the transmission. The *R, *C, and *E commands perform those functions. Storing Passwords & Callback Numbers (*Pn) The *Pn command stores or deletes a password and (optional) callback number in location n. *Pn:password:callback# Location n may be any number from 0 to 19. Passwords must be alphanumeric, and be at least 6 characters and no longer than 12 characters long. The callback number may be up to 40 characters long. If a callback number is to be associated with the password, it must follow the password and colon (:) separator. If the callback number and colon separator are omitted, a password verification will occur, but the modem will not institute a callback. Entering *Pn: without a password will delete any existing password at location n. For example, this command sets the password "word1" and callback number "15035555555" at location 1: AT *P1:word1:15035555555 Listing Passwords & Callback Directories (*L) The *L command displays all secure access passwords and callback numbers stored with *Pn command. Requesting Secure Access Mode (*R) The *R command requests that your modem place in secure access mode the remote modem attempting to connect with it. This command will only be accepted if the local modem is in an online command state during an error- corrected connection. Enabling Secure Access & Requesting Password (*C) Once secure access has been accepted, the *C command enables secure access and instructs the local modem to request a password from remote modems attempting to connect with it. If the password entered by the remote modem matches any on the list of passwords in *L, the local modem will initiate the callback (if a callback number is attached to the password), or will attempt to connect with the remote modem (if no callback number is attached). This command works with error-corrected connections only. If no passwords have been stored with *P, the modem will respond to the default password, QWERTY. Exiting Secure Access (*E) The *E command exits remote configuration mode and transmits the OK result code. 140 CCITT V.32BIS, 14,400 BPS DATA Modems that include option 140 use the CCITT V.32bis standard for 14,400 bps data speeds. 141 SILENT ANSWER Support for the Silent Answer feature which directs the handling of incoming fax and voice calls. See Chapter 5 for more information. 142 CALLER ID Includes support for the Caller ID function. You must also have Caller ID support from your telecommunications provider and your software. See Chapter 5 for more information. 143 MNP 10 Support for the MNP command set which is briefly described below. -B Forced Fallback to 1200 bps Fall back to 1200 bps at -10 dBm. -C Enable/Disable MNP 2, 3, and 10 Enable/disable MNP 2, 3, and 10. -C MNP 10 enabled, synchronous mode. -C1 MNP 10 enabled, asynchronous mode. -C2 MNP 2 enabled. -C3 MNP 3 enabled. -K LAPM-to-MNP Conversion -K Do not convert a LAPM connection to an MNP connection (default). -K1 Convert a LAPM connection to an MNP 10 connection if -K1 is used on both modems. -Q Fallback to V.22/V.22bis -Q0 Enabled. -Q1 Disabled. -U Forced Transmit Level Change During Fall Forward Forces the transmit level to change to a predetermined level during a fall forward. This command has no effect if the line speed is already 2400 bps. -U Allows automatic attenuation to -10 dBm. -U1 Allows automatic attenuation to as low as -18 dBm. -U2 Allows automatic attenuation to as low as -22 dBm. -U3 Allows automatic attenuation to as low as -25 dBm. -U4 Forces 2400 bps transmit level to -10 dBm. -U5 Forces 2400 bps transmit level to -18 dBm. -U6 Forces 2400 bps transmit level to -22 dBm. -U7 Forces 2400 bps transmit level to -25 dBm. )M Transmit Level Adjustment for Cellular Connection )M Automatically adjust transmit level if remote modem is set to )M1 otherwise, transmit level is fixed at -10 dBm. )M1 When your modem is trying to connect to another MNP 10 modem and either or both modems are set to )M1, both modems will try to reduce the power level to less than -10 dBm. *H Link Negotiation Rate *H Negotiate link at the highest supported speed. *H1 Negotiate link at 1200 bps (useful with poor telephone lines). If this command is used and the modems make a LAPM connection, the connection rate will be fixed at 1200 bps. *H2 Negotiate link at 4800 bps. 144 MNP CELLULAR Supports the standards for data transfer from a cellular telephone connection. 145 AUTOSYNC A standard protocol for emulating synchronous communications. 146 ENHANCED CONFIGURATION DISPLAY Utilizes the \S Command for enhanced configuration display. See Chapter 7 and Appendix B for more information. 160 VOICE PROCESSING If your modem supports voice processing capabilities, these capabilities are explained in separate documentation included with your modem. ******************************************************************************** APPENDIX B: AT COMMAND DESCRIPTIONS ******************************************************************************** This appendix describes data mode commands your modem supports. +++ Escape Code _- See Chapter 2 A Answer Phone Line _- See Chapter 5 A/ Re-execute Last Command _- See Chapter 2 AT "ATtention" Command Line Prefix -_ See Chapter 2 B BELL/CCITT Protocol Compatibility _- See Chapter 6 Dn Dial Telephone Number -_ See Chapter 4 E Command Echo Controls the echo of characters sent to your modem from your computer when the modem is in the command state. E Inhibit command. If you see two characters for every one you type (i.e. AT looks like AATT), issue E. E1 Enable command echo (default). If your computer does not display the characters you type, issue E1. H Hook Control H On-hook (hang up). H1 Off-hook (pick up phone line). I Report Identification & Diagnostic Information I Report product code I.D. I1 Perform a checksum computed on the firmware ROM, and returns three ASCII numeric characters followed by a carriage return and line feed character. I2 Perform a checksum on the firmware ROM, and returns OK or ERROR. I3 Report ROM code revision number. I4 Report supported protocols, in encrypted format. I5 Report firmware copyright information. I10 Report optional features supported by your modem. Appendix A provides more information. L Speaker Volume L=low, L2=medium (default), L3=high. M Speaker Control M Always off. M1 On until carrier is received (default). M2 Always on. M3 Off while dialing and after carrier is received; on when answering. N Connection Rate _- See Chapter 6 N Connect only at rate specified in S37, or, if S37=0, connect at the rate at which the last AT command was issued. Only attempts connection protocols specified by the B command. N1 Connect at the highest rate supported by both modems. The B command setting is ignored, and the modem attempts best possible connection (default). O Going Online O Go online. O1 Go online; initiate retrain sequence if connected at or above 2400 bps. P Pulse Dialing Use pulse dialing for all subsequent dial commands. Q Enable/Disable Result Codes _- See Appendix A Q0 Result codes enabled (default). Q1 Result codes disabled. Sr? Read S Registers -_ See Chapter 7 Return the value in S register r. Sr=n Write to S Registers -_ See Chapter 7 Write value n to S register r. T Tone Dialing Use tone dialing for all subsequent dial commands. V Verbose / Numeric Result Codes -_ See Appendix C V Numeric result codes. V1 Verbose result codes (default). W Error Correction Result Codes -_ See Appendix C W Result codes not reported and CONNECT XXXX reports computer (DTE) rate (default). W1 Result codes reported. W2 Result codes not reported and CONNECT XXXX reports connection (DCE) speed. X Dialing Type and CONNECT Result Codes X Blind dial (ignore dial tone and busy signal) and send CONNECT when connected. X1 Blind dial; send CONNECT XXXX result codes when connected. X2 Wait for dial tone before dialing; send CONNECT XXXX result codes; do not detect busy signal. X3 Ignore dial tone; send CONNECT XXXX result codes; send BUSY if busy signal detected. X4 Wait for dial tone before dialing; send CONNECT XXXX result codes when connected; send NO DIALTONE code if dialtone is not received in 5 seconds; send BUSY if busy signal detected (default). Zn Reset and Load Stored Configuration -_ See Chapter 7 Reset modem and load configuration stored in n (n=0 (default) or 1). &C Select Behavior of Data-Carrier-Detect (DCD) Determines DCD behavior. Default depends on &F setting. &C DCD signal always on. &C1 DCD indicates when carrier from remote modem is present. &D Select Modem Reaction to DTR Sets how your modem reacts to an on-to-off transition of DTR. This command acts differently depending on the &Q command setting. Default depends on &F setting. | &D0 | &D1 | &D2 | &D3 | --------------------|--------|-------|-------|-------| &Q0, &Q5, &Q8, &Q9 | none | 2 | 3 | 4 | --------------------|--------|-------|-------|-------| &Q1 | 1 | 2 | 3 | 4 | --------------------|--------|-------|-------|-------| &Q2 | 3 | 3 | 3 | 3 | --------------------|--------|-------|-------|-------| &Q3 | 3 | 3 | 3 | 3 | --------------------|--------|-------|-------|-------| &Q4 | 1 | 2 | 3 | 4 | --------------------|--------|-------|-------|-------| 1. Disconnect and send OK result code. 2. Switch to asynchronous command state. 3. Disconnect and return to command state. Auto answer mode disabled while DTR is off. 4. Perform soft reset (similar to ATZ command). Note: When the modem is online, it ignores a change of DTR that persists for less time than the value in S25 (default = .05 seconds). &F Load Factory Default Configuration -_ See Chapter 7 &F Direct mode operation (without error correction, data compression, or Rate Renegotiation). &F1 Preferred error correction and data compression operation for Macintosh. &F2 Preferred error correction and data compression operation for IBM (and others). &K Serial Port Flow Control -_ See Chapter 3 The default depends on the &Fn command used. &K Disable flow control. &K3 Enable bidirectional hardware (RTS/CTS) flow control. &K4 Enable software (XON/XOFF) flow control. &K5 Enable transparent software flow control. &M Asynchronous/Synchronous Mode Selection Same as &Q &P Select Make/Break Ratio for Pulse Dial Sets pulse dialing make (off-hook) to break (on-hook) ratio and pulse rates. &P Select 39%/61% make/break ratio and 10 PPS (USA/Canada -_ default). &P1 Select 33%/67% make/break ratio and 10 PPS (UK/Hong Kong). &P2 Select 33%/67% make/break ratio and 20 PPS (Japan). &Q Asynchronous/Synchronous Mode Selection Same as &M. Default depends on&F &Q Asynchronous Direct mode. &Q1 Synchronous mode 1. Synchronous mode 1 is used with terminals that support both synchronous and asynchronous. After the call is placed in asynchronous mode, the modem switches to synchronous. If DTR goes from on to off, the modem returns to asynchronous. &Q2 Synchronous mode 2. In synchronous mode 2, a stored number is dialed on an off-to-on transition of DTR. This number must be stored in location 0 with an asynchronous terminal using &Zx=n. The modem returns to asynchronous mode on an on-to-off transition of DTR. &Q3 Synchronous mode 3. Synchronous mode 3 is for manual dialing. With DTR off, dial the number. Then turn DTR on and hang up the voice phone. The off-to-on transition of DTR must be recognized by the modem before the phone hangs up or the connection will be lost. &Q4 Reserved. &Q5 Asynchronous Reliable mode (default). &Q6 Asynchronous Normal mode. &Q7 Reserved. &Q8 Causes modem to act as though S48=128 (fall back to MNP). If S36 holds an odd value, the modem acts as though S36=7; otherwise, it acts like S36=5. &Q9 Causes modem to act like &Q5 with S48=7 and S46=138. The modem will attempt V.42bis, fall back to V.42, and then fall back to Normal mode. &V Show Configuration Profiles Display active and stored configurations. Also see \S. &Wn Write Active Configuration to Memory -_ See Chapter 7 Write active configuration to nonvolatile memory location 0 or 1. Do not place the &W command in your software initialization string, an often-used script, or anything else that will cause it to be executed frequently. The modem's nonvolatile RAM can be written to (by &W) approximately 100,000 times before it dies. The RAM should easily last for as long as you use your modem. But if your software issues the &W command repeatedly when it is not necessary (e.g., from the init string), your nonvolatile RAM may die prematurely. Instead, when you need to execute &W, do so from your software's terminal mode. For more information on &W, nonvolatile RAM, and terminal mode, refer to Chapters 2 and 7. &Yn Load Configuration Profile at Power-Up -- See Chapter 7 Load stored configuration 0 or 1 at power-up. &Zx=n Store Telephone Number _- See Chapter 4 \N Operating Mode _- See Chapter 3 \N Normal Mode. \N1 Direct Mode. \N2 MNP Reliable Mode. \N3 AutoReliable Mode (default). \N4 LAPM/MNP Reliable Mode. \S Report Active Configuration (Optional Feature #146) _- See Chapter 7 Provides a detailed listing of all current settings in your modem's active configuration. This feature is only available on select modem models. The I10 command tells which optional features your modem supports. Also see &V. %C Enable/Disable MNP 5 %C Disabled. %C1 Enabled (default). %E Auto Retrain _- See Chapter 8 %G Initiation of Rate Renegotiation _- See Chapter 8 %L Report Received Signal Level Returns a value representing the received signal level in -dBm. The value 009 represents -9 dBm (or more), 010 is -10 dBm, 011 is -11 dBm, etc. The value 043 represents -43 dBm or less. Generally, the smaller the number is, the better the connection is. %Q Report Line Signal Quality Report line signal quality. Full range of %Q is 0 to 128. The lower the number, the better the line quality. This is an instantaneous reading; for increased accuracy, the %Q command should be repeated several times. ******************************************************************************** APPENDIX C: RESULT CODES ******************************************************************************** The following commands control result codes. Q Enables result codes (default). Q1 Disables result codes. V Displays result codes as numbers. V1 Displays result codes as words (default). W Reports computer (DTE) rate only as CONNECT XXXX (default). W1 Reports computer rate as CONNECT XXXX, error correction used as PROTOCOL: XXXX, and connection rate as CARRIER XXXX. W2 Reports connection rate only as CONNECT XXXX. S95=32 Enables COMPRESSION XXXX result codes. S95=0 Disables COMPRESSION XXXX result codes. SAMPLE RESULT CODES The following result code is returned when your computer rate is set to 38,400 bps in your telecommunications software; your modem connects to a 9600 bps modem that supports V.42; and result codes are enabled (Q0); set to be returned as words (V1); and set to report throughput, error correction, and connection rate (W1). CARRIER 9600 PROTOCOL: LAPM CONNECT 38400 These results codes indicate a 9600 bps connection rate, LAPM (V.42) error correction, and 38,400 bps maximum throughput. With the same example, W0 would return only CONNECT 38400 (computer rate) and W2 would return only CONNECT 9600 (connection rate). WHICH RESULT CODES SHOULD YOU USE? The result code commands you need depend on your software. It is nice to have all of the codes turned on, but some software only expects a CONNECT XXXX result code and may get confused with the extra information provided by a command such as W1. The factory default settings ensure compatibility with most software. COMPLETE LIST OF POSSIBLE RESULT CODES The following result codes are available on your modem. NUMBERIC FORM WORD FORM 0 OK 1 CONNECT 2 RING 3 NO CARRIER 4 ERROR 5 CONNECT 1200 6 NO DIALTONE 7 BUSY 8 NO ANSWER 9 CONNECT 0600 10 CONNECT 2400 11 CONNECT 4800 12 CONNECT 9600 14 CONNECT 19200 16 CONNECT 19200 17 CONNECT 38400 18 CONNECT 57600 40 CARRIER 300 46 CARRIER 1200 47 CARRIER 2400 49 CARRIER 7200 50 CARRIER 9600 51 CARRIER 12000 52 CARRIER 14400 66 COMPRESSION CLASS 5 67 COMPRESSION V.42BIS 69 COMPRESSION NONE 70 PROTOCOL: NONE 77 PROTOCOL: LAPM 80 PROTOCOL: ALT (MNP) ******************************************************************************** APPENDIX D: S REGISTER DESCRIPTIONS ******************************************************************************** S0 Number of Rings to Auto Answer (range = 0-255; 0 = disabled; default = 0) The number of rings the modem waits for before it auto answers. S1 Ring Counter (range = 0-255; default = 0) The number of telephone rings. This register is reset to 0 if it detects no rings for eight seconds. S2 Escape Code (range = 0-255; default = 43 "+") The ASCII value of the escape code. Values greater than 127 cause the escape code to be disabled. S3 Carriage Return (range = 0-127; default = 13) The ASCII value of the carriage return control character, which serves as command line terminator and result code terminator. S4 Line Feed (range = 0-127; default = 10) The ASCII value of the line feed control character. S5 Backspace (range = 0-32; default = 8) The ASCII value of the backspace control character. S6 Time to Wait to Blind Dial (range = 2-255; default = 2; units = seconds) The maximum time to wait for a dial tone after going off-hook before dialing a number. The W dial command modifier overrides S6. S6 does not apply when X2 or X4 is in effect. S7 Time to Wait for Carrier (range = 1-255; default = 50; units = seconds) The maximum time the originating modem waits for a carrier from the remote modem before hanging up, or the time the modem waits when the W dial command modifier is used. S8 Pause Time for Comma Dial Command Modifier (range = 0-255; default = 2; units = seconds) The length of the pause caused by a comma in a dial command (D). S9 Time to Wait Before Recognizing Carrier (range = 1-255; default = 6; units = 1/10 seconds) The length of time after a carrier first appears that the modem waits to recognize carrier and turn on DCD. This delay lets your modem ignore spurious signals that are the same frequency as the carrier. Higher S9 values reduce the chance of a false carrier being detected. S10 Delay from Lost Carrier to Hang Up (range = 1-255; default = 14; units = 1/10 second) The time your modem waits for a carrier to return before disconnecting. A long enough time allows the remote modem's signal to momentarily disappear without making your modem disconnect. The actual time your modem waits for a lost carrier after it disappears is the difference between S9 and S10. S10=255 causes your modem to act as though a carrier is present, whether one is or not. S11 DTMF Tone Duration/Spacing (range = 50-255; default = 95; units = 1/1000 second) The spacing between and duration of DTMF (dial) tones during tone calling. The spacing between tones is equal to the duration of each tone. S12 Escape Code Guard Time (range = 0-255; 0 disables timer; default = 50; units = 1/50 second) The delay required before and after entering the escape code. S25 Delay to DTR (range = 0-255; default = 5; units = 1/100 second) The shortest length of a DTR change the modem recognizes. If &D2, the modem will not hang up if the transition is less than S25. S36 Negotiation Failure Treatment (range = 0-7; default = 7) Fallback options initiated when S48=128 or an attempted error correction link fails. 0 Disconnect. 1 Establish a Direct connection. 3 Establish a Normal connection. 4 Establish an MNP connection if possible. Otherwise, disconnect. 5 Establish an MNP connection if possible. Otherwise, establish a Direct connection. 7 Establish an MNP connection if possible. Otherwise, establish a Normal connection. S37 Desired Line Speed (range = 0-7; default = 0) The highest rate at which your modem attempts to connect with a remote modem: 0 Rate of the last AT command issued, or 14,400 (9600) bps if last command speed was greater than 14,400 (9600) bps (default). 1 300 bps. 5 1200 bps. 6 2400 bps. 8 4800 bps. 9 9600 bps. 10 12,000 bps. 11 14,400 bps. 12 7200 bps. S38 Delay Before Forced Disconnect (range = 0-255; default = 20; units = seconds) The delay between your modem receiving the H command (or an on-to-off transition of DTR if your modem is set to follow DTR) and disconnecting. If S38 is between 0 and 254, your modem waits for the time in S38 for the remote modem to acknowledge all data in the modem buffer before disconnecting. NO CARRIER indicates time expired before all data was sent, and data has been lost. OK indicates all data was transmitted. If S38 is 255, the modem attempts to deliver data in the buffer until the connection is lost or the data is delivered. S46 Protocol Selection (range = 136, 138; default = 138) Compression is disabled if S46=136, enabled if S46=138. S48 V.42 Negotiation (range = 0, 7, 128; default = 7) V.42 negotiation determines the capabilities of the remote modem. When these capabilities are known, negotiation can be bypassed. 0 Disable negotiation; proceed with LAPM. 7 Enable negotiation. 128 Disable negotiation; follow fallback action specified in S36. S85 Connection Failure Cause Code (range = 0, 4, 5, 9, 12-14; default = 0) S86 records the first event that contributes to a NO CARRIER message. 0 Normal disconnect; no error. 4 Loss of carrier. 5 V.42 negotiation failed. 9 Modems could not find common protocol. 12 Normal disconnect initiated by remote modem. 13 Remote modem did not respond after 10 retransmissions of same message. 14 Protocol violation. S95 Extended Result Codes A bit set to 1 in S95 enables the corresponding result code regardless of the W command setting. 0 CONNECT XXXX result code indicates DCE speed instead of DTE speed. 1 Append /ARQ to verbose CONNECT result code if protocol is not NONE. 2 Enable CARRIER XXXX result code. 3 Enable PROTOCOL XXXX result code. 4 Reserved. 5 Enable COMPRESSION result code. 6, 7 Reserved. S109 Range of Available Modem Speeds _- See Chapter 8 (range=0-255; default=62) S110 V.32bis Options _- See Chapter 8 (range=0-3; default=2) ******************************************************************************** APPENDIX E: RS-232C PIN ASSIGNMENTS ******************************************************************************** The following table summarizes the modem's RS-232C pins. ------------------------------------------------------------------- PIN | EIA | ABBREV. | SOURCE | DESCRIPTION ----|-----|---------|--------|------------------------------------- 1 | AA | shield | n/a | protective ground ----|-----|---------|--------|------------------------------------- 2 | BA | TXD | DTE | transmit data ----|-----|---------|--------|------------------------------------- 3 | BB | RXD | DCE | receive data ----|-----|---------|--------|------------------------------------- 4 | CA | RTS | DTE | request to send ----|-----|---------|--------|------------------------------------- 5 | CB | CTS | DCE | clear to send ----|-----|---------|--------|------------------------------------- 6 | CC | DSR | DCE | data set ready ----|-----|---------|--------|------------------------------------- 7 | AB | GND | n/a | signal ground ----|-----|---------|--------|------------------------------------- 8 | CF | DCD | DCE | data carrier detect ----|-----|---------|--------|------------------------------------- 12 | CI | SI | DCE | data speed indicator ----|-----|---------|--------|------------------------------------- 15 | DB | TCLK | DCE | transmit clock (sync. only) ----|-----|---------|--------|------------------------------------- 17 | DD | RCLK | DCE | receive clock (sync. only) ----|-----|---------|--------|------------------------------------- 20 | CD | DTR | DTE | data terminal ready ----|-----|---------|--------|------------------------------------- 22 | CE | RI | DCE | ring indicator ----|-----|---------|--------|------------------------------------- 23 | CI | SI | DCE | data signal rate selector ----|-----|---------|--------|------------------------------------- 24 | DA | XTCLK | DTE | external transmit clock (sync. only) ------------------------------------------------------------------- ******************************************************************************** APPENDIX F: FCC & DOC RULES ******************************************************************************** FEDERAL COMMUNICATIONS COMMISSION (FCC) Your modem has been tested and found to comply with limits for a Class B computing device according to the specifications in FCC rules Part 15 and Part 68. As an owner and/or operator of a registered modem like this modem, you must comply with these rules: * Before installing your modem, you must notify your telephone company that you are going to install an FCC registered device. When you contact them, you must provide the FCC registration number and ringer equivalence number (REN) for your modem; these numbers are on your modem. * You cannot connect the modem to a party line or to a coin telephone line. * You must only connect your modem to a standard modular telephone jack, type RJ-11. * You must use a shielded RS-232C cable to connect your external modem to your terminal. This equipment, like other electronic equipment, generates and uses radio frequency energy. If not installed and used according to the instructions in this manual, this equipment may cause interference with your radio and television reception. If you believe that this equipment is causing interference with your radio or television reception, try turning the equipment off and on. If the interference problems stop when the equipment is switched off, then the equipment is probably causing the interference. You may be able to correct the problem by doing one or more of the following: * Adjust the position of the radio or TV antenna. * Move the modem away from the radio or TV. * Plug the modem into a different outlet than the radio or TV uses. If necessary, consult your dealer or an experienced radio or television technician. You may find this booklet helpful: "How to Identify and Resolve Radio and TV Interference Problems" (Stock No. 004-000-00345-4), prepared by the FCC and available from the U.S. Government Printing Office, Washington, DC 20402. See individual modems for FCC ID and registration numbers. CANADIAN DEPARTMENT OF COMMUNICATIONS (DOC) The DOC label identifies certified equipment. Certification means that the equipment meets certain telecommunications network protective, operational and safety requirements. The DOC does not guarantee the equipment will operate to the user's satisfaction. Before installing this equipment, ensure that it is permissible to be connected to the facilities of the local telecommunications company. Install the equipment using an acceptable method of connection. Service may be extended by means of a certified connector assembly (telephone extension cord). Compliance with the above conditions may not prevent degradation of service in some situations. Repairs to certified equipment should be made by an authorized Canadian maintenance facility designated by the supplier. Any repairs or alterations made by the user to this equipment, or equipment malfunctions, may give the telecommunications company cause to request the user to disconnect the equipment. For your own protection, ensure the electrical ground connections of the power utility, telephone lines and internal metallic water pipe system, if present, are connected together. This precaution may be particularly important in rural areas. CAUTION _- Do not attempt to make such connections yourself. Contact the electric inspection authority, or electrician, as appropriate. The Load Number (LN) assigned to each terminal device denotes the percentage of the total load to be connected to a telephone loop which is used by the device, to prevent overloading. The termination on a loop may consist of any combination of devices subject only to the requirement that the total of the Load Numbers of all the devices does not exceed 100. Load Numbers can be found on a sticker on the modem. ******************************************************************************** APPENDIX G: RESOURCES ******************************************************************************** The following resources provide a wide range of helpful information on telecommunications. * Getting Started manual In addition to helping you get your modem and software installed, this manual will help you get online as soon as possible. * Software manuals Provide detailed information on the software you will use to perform telecommunications tasks. * Chapter 8 in this manual Explains the most common problems encountered when using a modem. * Telecommunications books You will find telecommunications books especially helpful if you are very new to telecommunications, or if you are at the other extreme _- a "techie." You may be able to find these books at computer stores, general bookstores, college bookstores, and libraries. Some of the more popular books include: - Dvorak's Guide to PC Telecommunications, John C. Dvorak and Nick Anis, Osborn McGraw-Hill, Inc., 1992, ISBN #0-07-881551-7 - The Modem Reference, Third Edition, Michael A. Banks, Brady Publishing, 1992, ISBN#1-56686-027-X - The BMUG Guide to Bulletin Boards and Beyond, Bernard Aboba, BMUG Inc., 1992, ISBN #1-879791-03-X (Macintosh only) ******************************************************************************** GLOSSARY ******************************************************************************** AutoReliable Mode The mode in which the modem makes the best possible connection, either Reliable or Normal. CCITT V.42 The international standard protocols for error correction (MNP 2-4 and LAPM). CCITT V.42bis The international standard protocols for error correction (MNP 2-4 and LAPM) and 4:1 data compression (BTLZ). Connection Rate The rate at which modems communicate over a phone line. Synonyms: Transmission Speed, Line Speed, Modem-Modem Speed, DCE-DCE Rate. Command State When your modem will accept AT commands. Synonym: Escape State. See also Online State. Computer Rate The rate at which a modem (DCE) and a computer (DTE) communicate. This is what changes when you set rate in your telecom software. Synonyms: Serial Port Rate, Modem-Computer Speed, DTE-DCE Rate,Communications Rate. Data Compression The process of reducing the size of data parcels to transmit more data in less time. See also Error Correction/Data Compression Protocols. DCE Data Communications Equipment. Your modem. See also DTE. Direct Connection Any standard modem connection, without error correction, data compression, or flow control. Computer rate must equal connection rate. DTE Data Terminal Equipment. Your computer or terminal. In this manual, the term computer rate is used to mean DTE. See also DCE. Error Correction The process of verifying the accuracy of transmitted data and retransmitting data that did not transfer successfully. Error Correction/Data Protocols that increase the amount of data that can be Compression Protocols transferred (data compression) and/or improve the accuracy of transmissions (error correction). Some are MNP 2-5, V.42, V.42bis. Fax Protocols Protocols (defined by the international CCITT standards committee) that serve as standards to let fax devices (faxmodems and fax machines) communicate at specific rates. Some are CCITT V.17, CCITT V.29, and CCITT V.27ter. Flow Control A buffering system that optimizes throughput by allowing your computer and connection rates to be different. Local Modem Your modem. MNP Microcom Networking Protocol. Protocols providing error correction (MNP 2-4, MNP 10) and 2:1 data compression (MNP 5). Negotiation The process where your modem and the remote modem determine what type of connection to make. Synonyms: Detection, Detection Phase. Normal Connection Same as a Direct connection, but with the addition of flow control, which allows the computer and connection rates to be different. A Normal connection does not support error correction or data compression. Online State When you can communicate with the remote computer. See also Command State. Physical Protocols Descriptions of actual electronic signals used to communicate over phone lines. For example, Bell 103/212A, CCITT V.21/V.22/V.22bis/V.32/ V.32bis. Synonym: Transmission Protocols. Reliable Connection A connection that uses one of the error correction or data compression protocols available. Remote Modem The modem to which you connect. Throughput Effective transfer rate. Generally speaking, on a 9600 bps connection, data will transfer at a maximum of 9600 bps, so maximum throughput is 9600 bps. But on a 9600 bps MNP 5 connection, where MNP 5 compresses the data to half its size, throughput can be double that of the non- MNP 9600 bps connection, or 19,200 bps ******************************************************************************** IF YOU NEED HELP ******************************************************************************** CONTACTING SUPRA TECHNICAL SUPPORT Before calling: Please type the I3 command (if possible), as explained in Chapter 8. When calling, have the modem's response to this command handy. RESOURCE NUMBER HOURS DOS & Windows Technical Support (503) 967-2450 5am-7pm PST, M-F; 8am-4pm PST, Sat SupraSupport BBS (503) 967-2444 24 Hours Technical Support Fax line (503) 967-2401 24 Hours Caution: Do not return any equipment to Supra for service without first contacting us and obtaining a Return Materials Authorization (RMA) number. We need this for proper tracking of your repair. ******************************************************************************** SupraCOMcard and SupraFAXModem are trademarks of Supra Corporation. All other trademarks belong to their respective owners. Manual Copyright 1993 Supra Corporation. ********************************************************************************