Comtrol DeviceMaster DM-2000 Series Installation And Configuration Manual page 165

f. Close the telnet (PuTTY) session that you opened from PortVision DX.
g. Re-open the telnet session by right-clicking the DeviceMaster, and select the Telnet / SSH Session
option.
h. Enter the Socket Port number and then click Ok.
i. Enter 123, single digits should appear.
14. Remove the loopback plug and type abc. No characters should display because the return path is open.
15. Re-attach the loopback plug, type abc, and the characters should appear.
16. If you want to test additional ports, simply repeat this procedure on that port or ports.
17. Remove the loopback plug from the serial port and attach your serial device.
You may need to set the serial parameters as necessary to match your attached equipment.
DeviceMaster Installation and Configuration Guide: 2000594 Rev. F
Troubleshooting and Technical Support
Troubleshooting and Technical Support - 165