ECOMLT not servicing Modbus requests

[Controls Guy]

I have an application being commissioned where I was going to use the internal port for remote programming access (and HMI if used in future), and a Modbus/TCP client at the site is transmitting requests to an ECOM on a separate subnet (buying EX's now but this is a leftover LT).

The client and I could both ping the LT, but it wouldn't respond to Modbus queries.   I swapped the IP addresses between the internal and POM ports and the internal one works fine for Modbus.   Modbus/TCP is enabled/checked, 10 sessions, port 502.   The POM works fine for DM protocol for programming.

I've done this config many many times with no issue, and don't remember ever having to configure anything to make it work.   Is this POM semi-faulty or what?   Very weird.

[BobO]

I have an application being commissioned where I was going to use the internal port for remote programming access (and HMI if used in future), and a Modbus/TCP client at the site is transmitting requests to an ECOM on a separate subnet (buying EX's now but this is a leftover LT).

The client and I could both ping the LT, but it wouldn't respond to Modbus queries.   I swapped the IP addresses between the internal and POM ports and the internal one works fine for Modbus.   Modbus/TCP is enabled/checked, 10 sessions, port 502.   The POM works fine for DM protocol for programming.

I've done this config many many times with no issue, and don't remember ever having to configure anything to make it work.   Is this POM semi-faulty or what?   Very weird.

POM firmware?

[Controls Guy]

Ooh, good question!   I'd forgotten that Modbus server wasn't initially in the POM, AND this unit came out of my desk drawer and had been used as a programming tool, AND the project was sold, put together and shipped literally in a half day.   Plus I'm trying to move any LT's I have left to make way for the EX's.

Now that you mention it I'm almost sure that's the issue.  My partner is still onsite till tomorrow, I'll check the FW Rev on the POM.

Thanks BobO