Help on Lantronix UDS-1100 IAP - Modbus Gateway

Old thread: https://www.plctalk.net/qanda/showthread.php?t=114187

I have configured many other gateway before but I can't figure this out. It seems they are missing some documentation.

Have the device on hand, already updated the firmware to the "modbus" version and now am lost on what to do next. Typically, there's a database cross-ref function but I can't see it anywhere.

Background: Old: 4 modbus slave devices on RS485, connected to PC with 485/232 converter. Application side is Kepware - Modbus RTU. This setup works.

New: same slaves going to Kepware but via Modbus TCP. Trying to use UDS-1100 as the gateway.

Reading between the lines, I figured out that the Lantronix works a bit different than other gateway. It doesn't have a cross-ref table but rather just pass things on and use the modbus device ID on the TCP side.

Still figuring out the rest though. Can't get a response yet and I haven't found a way to troubleshoot the TCP independently from the serial side, unlike other gateway I dealt with in the past. Any suggestions?

Also, this is UDS-1100-IAP with the Modbus firmware.

It sounds like that it converts serial to serial over TCP. It is different than Modbus TCP.


On kepware you still need configure serial modbus driver and then select ethernet encapsulation.

I think that only applies if it's using the standard firmware, instead of the "modbus firmware". However, it's easy to try so I'll report back.