On the RS232 LoopBack tab, you can perform a loopback test on a single port using an RS232 Self LoopBack Unit.
Connect a serial loopback connector to the workstation COM port 1, 2, or 5 (COM 5 is only available on the 610). You can also connect a serial cable between two COM ports.
Select the output and input ports.
Press Test Ports.
Verify that the Tx Bytes field and the Rx Bytes field increments.