Detecting if Modbus TCP-RTU gateway loses connection to the RTU device

Ignition
1

I'm setting up a bunch of devices which have Modbus RTU communication to talk to an Ignition gateway. I'm using a Moxa MB3170 as a transparent TCP-RTU gateway.

When I add the MB3170 to Ignition, I'll get some status tags that I can use to check whether Ignition is able to communicate with the MB3170. What I don't know is how to determine whether or not the MB3170 is communicating to the target device.

If I'm using an MB3170 in this manner, would the tags report bad quality if the MB3170 was online, but it could not reach the target RTU device?

Has anyone else done this before and found a reliable method of confirming that the serial side of the gateway is communicating properly?

2

The requests will start timing out and you'll end up with bad quality.

Or the gateway might report Modbus Exception 11 (0x0B) - "Gateway Target Device Failed to Respond", with the same result for your tags - bad quality.

3

Perfect, thanks Kevin!