SIL_ANSR.TXT rev 2.1 (11/17/94phm) from Supra BBS (503)967-2444


What is Silent Answer?

Silent Answer is a feature available on most SupraFAXModems.  It allows you
to receive incoming voice and fax calls on a single phone line unattended.
The modem will listen in on calls to determine if it is a fax and will either
ignore the call or attempt to receive a fax.  Some setup of your software and
telephone cabling is required.  Silent Answer is not enabled when you
purchase the modem and install the software.
 

Can I use Silent Answer?

        In order to use Silent Answer you will need the following:

        - A SupraFAXModem V.32bis, SupraFAXModem 144LC, SupraFAXModem 144i,
          SupraFAXModem 144PB, SupraFAXModem V.32, SupraFAXModem 288,
          SupraFAXModem 288i or SupraFAXModem 288PB.

        - SupraFAXModem rom(s) supporting Silent Answer.  All SupraFAXModem
          288 modems support Silent Answer.  If you have one of the other
          modems listed above you need one of the following rom versions to
          be able to use Silent Answer: 1.4x, 1.5x, 1.7x, 1.8x.  Rom versions
          1.200-H, 1.200-J and 1.200-L also support Silent Answer if you are
          using WinFax or FaxTalk on your PC.

        To find out what your rom version is issue the command ATi3 in your
        terminal communications software (MicroPhone, COMit, ZTerm, ProComm,
        White Knight, Telix, etc. on a Macintosh or COMit!, ProComm, Window's
        "Terminal", etc if on a PC).  Alternatively, on newer units you can
        issue the command ATi10 to see if you have the optional feature code
        141 listed.  If 141 is listed, your modem supports Silent Answer.

        - PC users need WinFax 2.0 or later, WinFax Lite, FaxTalk for DOS
          version 1.65C or later, FaxTalk for Windows, ProComm Plus for
          Windows v2.0, EclipseFax or Fax Works for OS/2.

        - Macintosh users need FAXcilitate 1.6 or later, FAXstf 2.2.3 or
          later or Delrina Fax Pro 1.5.1.

         (As of the date of this document, no other fax software is known
          to support the SupraFAXModem Silent Answer feature.)


How does Silent Answer work?

Silent Answer uses the ring signal to initiate the process.  Once the phone
has rung once the modem will go part way off hook to listen in on the call.
If the call has not been answered yet by you or your answering machine then
the modem will go back on hook (hang up) until another ring it detected.
This process will continue until the call has been answered by you or your
answering machine.  Once the call has been answered the modem will again go
part way off hook and listen ("snoop") on the line for CNG tones.  CNG tones
are an 1100Hz beeping sound that happen in 4-5 second intervals -- beep.....
beep.....beep....  If the modem detects a CNG tone is assumes the call is a
fax.  If it does not hear a CNG tone then it assumes the call is a voice
call.  Music played on an answering machine or the beep your answering
machine makes when its outgoing message is finished playing can trigger the
modem to think the call is a fax call.  If the modem does not detect a CNG
tone during the first 3 seconds it is snooping (after the call has been
answered by you or your answering machine) it will go back on hook for a
couple of seconds then snoop again, listening for the CNG tone for 6 seconds.
If no CNG tone is detected at that point the modem will stop snooping and
assume the call is not a fax.  If the modem does detect a CNG tone it will
send up to 9 fake ring signals to the software.  When the appropriate number
of rings are registered the software will issue the command for the modem to
go fully off hook and start sending out its signals to establish a fax
connection.  If you answered the call with your telephone you can then hang
up.  Do not hang up prior to hearing your modem respond to the CNG tones with
its own tones.  If your answering machine answered the call it should
automatically hang up once the modem goes fully off hook.  If it does not you
will need to purchase a device, generally called a Teleprotector, that will
cut off the answering machine.


How do I setup Silent Answer?

For information on setting up Silent Answer please download the appropriate
file for the fax software you are using or call our Faxback system and
request that the file be faxed to you (complete with helpful screen shots).
The phone number to call is 503-967-0072.  You will want file #1202 and one
of the following depending on your software:

   FAXcilitate 1.6 or later  #1222
   WinFax Lite, WinFax 2.0, WinFax Pro 3.0  #1211
   WinFax Pro v4.0  #1223
   FaxTalk for Windows  #1216
   FaxTalk for DOS  #1215
   FAXstf 2.2.3 or 2.6.1  #1212
   ProComm Plus for Windows v2.0  #1218
   FAXstf 3.0    #1221

 You need to use a touch-tone phone when calling into the FaxBack system.