1. Place the loopback plug into the corresponding port on the Digi product. Depending on the product, a loopback plug may or may not have been shipped with it.
2. From the UNIX root prompt, type:
# cat < /dev/[port_name] &
# date > /dev/[port_name]
If you see the date display on the screen where you issued the commands, this would indicate that the port is functioning properly.
3. Stop the initial cat command that is running in the background by typing:
# kill 0
: The [port_name] will vary depending on the UNIX flavor. Please refer to your installation guide if you do not know the particular port naming convention for your system.
Aug 23, 2017