3Com CS/2500 manual Changing Port Configuration

Changing Port Configuration 4-15

presence of an active pin 25 and automatically switches to RS-422 operation. This option affects all ports.

This setting acts as a toggle. To disable it, type 4 again.

Automatic RS-422 selection requires a different configuration for the RS-422 connector, in which pin 22 acts as a loopback for pin 25. For more information, refer to Appendix A, “Pin Assignments.”

5 To exit the System Default Configuration Menu, press the Escape key.