Digi One IAP 2 Wire 485

We are attempting to use a Digi One IAP as a convertor from Modbus on RS485 to Modbus TCP.

I have on here locally and it works exactly as I would expect. I can wire up the Terminal block using pins 3,4,5 or 5,6,7 and in both cases it works perfectly.

Or QA (located in another country) has a Digi One IAP, and I attempted to help them set it up exactly the same way. Same configuration, wiring and DipSwitch positions.

Ultimately we isolated the issue to that their Digi One, when in RS485 Half Duplex 2Wire mode is not joining Pins 3&6 and 4&7 internally.
We were able to get them running by manually joining the pins externally.

My Digi One is a few years (~5 I think) older and the one down there is fairly new.

Has something changed on the hardware?
What else could we be missing?

I am not aware of any changes to the RS485 HD circuity in the Digi One IAP. I have worked with customers using this mode recently, and they have not reported any issues.

I would use the CLI to confirm that the switches are set correctly. The command is “display switches” this will display how the serial port is set.

You do need to power cycle the device once you change the dip switches.

If you have verified the above. I would recommend open a support case @ tech.support@digi.com.