Some applications may have limited access to ports for connecting and testing devices. Often times the most accessible is the Ethernet port. This is where the Loop-back is useful.
Note: Before testing reset the adapter to factory settings.
- Make sure your PC has an IP address in the same subnet as the serial adapter.
- Connect your adapter to the Ethernet port of your PC or a connected switch.
- Connect pins 2 and 3 (Tx and Rx) of the serial DB-9 connector together using a wire. This creates the loop-back for the data.
- Run Tera Term and open a Telnet connection to the IP address and Port of the serial adapter you are testing.
- Type in the Terminal window and press enter. The characters you type will be sent out over the Ethernet connection to the adapter.
- Note: The characters will not appear in the window as you type. The window will only show data that has been received from the other end of the connection.
- When it reaches the serial connector, the data will be looped back through the wire between pins 2 and 3 of the DB-9 and sent back through the serial adapter to the terminal window.
- If the unit is working correctly with a complete connection, you will see the characters loop all the way back to the start and appear in the window.
- If the characters do not appear,
- Make sure the connections on the loop-back have good contact with the terminals.
- Check the Ethernet cable connection.
- Verify that the IP and Port are entered correctly.
- Check power to the adapter.
- Possibly a problem with the unit.