Modbus Security and Ignition

Ignition
30

All, I would like to thank everyone for helping me with this issue. I have found the solution and will leave it here for future reference.

I found 3 issues that was stopping communication:

  1. Flakey Network Port
    I can not get consentient pings to one of the 3 network ports. (The one labeled "For ModBus TCP" infuriatingly enough) I switched to another port and will reach out to manufacture for more info.

  2. Does not like to use ModBus TCP Slave ID 1.
    For some reason this manufactures ModBus TCP stack doesn't like to talk to ignition when I use slave Id 1 so I have changed it to 255. No reason for 255, just that it is a easy number to remember.

  3. Polling Rate. The main issue (I think). Apparently the 1 second default polling rate in Ignition is not fast enough. The device is closing the connection before any ModBus commands are sent. I set one tag to be in a faster polling tag group (500 ms and set it to Polling rather than subscribed) and that was enough to keep the connection alive.