C/X Remote with Multitech CSU/DSU


	Technical Support Drivers Firmware Upgrades FAQs Product Documentation Cabling Support Tools Legacy Products About Digi Support Knowledge Base Online Support Request FTP Site Related Links Inside Out Networks

Home > Support >kbase >

C/X Remote with Multitech CSU/DSU C/X Remote with Multitech CSU/DSU

C/X Remote with Multitech CSU/DSU The C/X and EPC/X concentrator systems can be setup for remote operation with a variety of synchronous links. The setup below is for a pair of Multitech MT56DSU2 CSU/DSUs over a DDS line. This setup has been tested and works well. This setup may also work well with the older version of the Multitech CSU/DSU, the MT56DSU, although none were available for testing at this time. If this status changes in the future, this document will be updated to reflect the current info.

Requirements:

An installed C/X Host Adapter (line set for 8W/RS232, clock speed=DDS line clocking speed) with C/CON Unit

A pair of MT56DSU2 CSU/DSU units

A pair of Digi RS232 Synchronous Modem cables

An installed DDS line (available via telco arrangement)

A back-to-back DSU cable for testing

Note: Prior to installing the C/CON or EPC/CON at a remote site, all of the components must be set up and tested at the Host Adapter location.

Set DIP switches on both MT56DSU2 units as follows for back-to-back operation:
- DIP switches 1, 2, and 3 determine the DSU clocking speed. These should be set to match the line speed of the DDS line installed by the telephone company (see label on underside of DSU for appropriate setting). This is also the same speed the driver must be set for in MPI.
- DIP switches 4 and 5 determine the source of clocking. For the back-to-back testing, set one DSU to internal clocking and the other to DDS. Internal is 4 and 5 up; DDS is 4 down, 5 up.
- DIP 6 and 7 down to force on interface signals RTS and DSR.
- DIP 8, 9, 10, 11, and 12 up for sync operation with all testing modes disabled.
- DIP 13 and 16 down, 14 and 15 up (defaults).
Connect the back-to-back DSU cable between the DSU connectors marked "Line".
Connect the RS232 sync modem cable from the C/X host adapter line to the RS232 connector of one of the DSUs. Connect the other RS232 sync modem cable from the C/CON unit host connector to the RS232 connector of the other DSU.
Turn on both MT56DSU2 units, then turn the C/CON unit on. The C/CON display should go from P1--P2--P4--AC. The link is operational when the display shows AC.
Set DIP 4 down, 5 up on both DSUs to set DDS clocking (i.e. clocking from the digital line). Now all that remains is to move the C/CON unit and MT56DSU2 with cable to the remote location and plug everything in. When you get AC on the C/CON, your work is complete.
For further help in diagnosing problems with C/X Remote installations, consult the C/X Remote Troubleshooting Guide