RS-232 Communications Cables
Connect the base to the host workstation or other device by plugging an RS-232 serial cable into the RS-
232 Communications Port on the rear of the base. The wiring of your cable depends on whether the other
device is set up as a Data Communications Equipment (DCE) or Data Terminal Equipment (DTE) device.
The Communication Port is configured as a DCE device. To communicate with a DCE device, use either
a null modem adapter in line with a standard RS-232 cable, or a null-modem serial cable. To communicate
with a DTE device such as a workstation, use a standard (or straight-through) RS-232 cable.
You can make your own cables by following the pin configuration in the chart below. To do so, you must
determine if your host RS-232 device is 9-pin or 25-pin, and whether it is configured as a DCE or DTE
device.
RS-232 Pin Configuration
Base /Host Port
IBM AT DB9
(DCE)
(DTE)
Pin / Input Signal
2 / (RD)
3 / (TD)
5 / (SG)
4 / (DTR)
6 / (DSR)
7 / (RTS)
8 / (CTS)
Note: This base cannot be daisy-chained.
IBM XT DB25
(DTE)
2
3
3
2
5
7
4
20
6
6
7
4
8
5
Modem DB25
(DCE)
2
3
7
6
20
5
4
11 - 9