Rockwell Automation T7150A Regent+Plus Communications Modules RS-232, RS-422 and RS-485 - Manual (Page 6)

Communications Modules (T7150A)
6
Industrial Control Services
Application
Communications Port Connections
Each communications port has a DB-25, female connector on
the front of the module. The RS232 and RS422/485 signals
are internally connected to the DB-25 connector pins as shown
in Table 1. Refer to Figures 3 through 5 for recommended
communications cable requirements and connections.
Table 1. Communications Port Pin-out.
Pin No. RS232
Signal
RS422/485
Signal
2 TX (not used)
3 RX (not used)
7 GND GND
9 (not used) + 5 VDC
10 (not used) TX (-)
11 (not used) RX (-)
22 (not used) TX (+)
23 (not used) RX (+)
Recommended Cable Type
For multidrop and Guarded Peer-Link communications a
Belden cable type 813x (where x = number of pairs) is
recommended. The cable has the following characteristics
that are important:
120 Ohm, Characteristic Impedance
Twisted Pairs
Overall shield
Communications Configurations
The communications module supports a variety of
communications configurations which are shown in Figures 3
through 5. Figure 3 illustrates two point-to-point