Network Router User Manual

8-8 EIA RS-232 Cabling
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RS-232 to DCP Conversion
This type of connection is shown for a DCP switch in Figure 8-5, Switched RS-232 to a DCP Switch Port.
• To convert an RS-232 channel to DCP mode 2, use a 7400A or 7400B Data Service Unit (DSU). In
this case, the channels can be used to originate and receive calls at speeds up to and including 19.2
Kbps.
An initialization string for the 7400A or 7400B will have to be entered on the AUDIX system :
translation : network port form.
— If a 7400A is used, make sure it is optioned for Data Communications Equipment (DCE). Lift off
the cover and check the vertical card at the front. If it reads DCE, the 7400A is okay. If not,
remove the card, turn it around, and reinstall it. If a 7400B is used, it does not require this step. It is
always optioned for DCE.
To set up the 7400A, go to the front panel and press the next/no button until the set interface options
comes up. Then press the yes button and choose INT=AT COMM.
— For a 7400B, set switch 1 to ON if there is no telephone connected to the data module. To get to
switch 1, lift the cover off the modem.
• To convert an RS-232 channel to DCP mode 1 (56 Kbps) or DCP mode 3 (64 Kbps), use a Modular
Processor Data Module, Model M1* (MPDM/M1*). In either of these cases, the channels can only be
used for incoming calls; they cannot be used for outgoing calls. All outgoing calls must use the DCP
ports. Make sure the MPDM/M1* has the option settings shown in the following table.
NOTE
If you are using an older version of the MPDM, it must be upgraded to an MPDM/M1*.
Use D-kit D-181509 and follow the instructions included with the kit.