Emerson ControlWave Instruction Manual page 125

Port Loop-back
Revised Aug-2015
Option
Discrete I/O
Ethernet
WINDIAG allows you to select the communication port (1 through 4)
Test to test. Depending on the type of network (RS-232 or RS-485) and the
port in question, a special loop-back plug is required:
 Ports 1, 2, and 4 (RS-232) use a 9-pin female D-type loop-back plug
(shown in Figure 5-22).
Figure 5-22. RS-232 Loop-back Plug
Figure 5-23. RS-485 Loop-back Plug
 Port 3 (RS-485) uses an 8-pin male RJ-45 loop-back plug (shown in
Figure 5-23).
These tests verify the correct operation of the communication interface
on ports COM1 through COM4.
: You cannot test a communications port while you are using it.
Note
You can only test currently unused ports. After you complete
testing on all other communication ports (and verify their correct
functioning), you must reconnect (using a now validated port)
and test the remaining untested port.
ControlWave I/O Expansion Rack Instruction Manual
Tests
Checks DIs on Digital Input Module, DOs on
Digital Output Modules.
Checks Ethernet Ports. The loop-back tests
require the use of a loop-back plug.
Service & Troubleshooting 5-29