Ignition Creating Communication Issues

Hi Guys,

I am busy migrating from our legacy SCADA system to Ignition and one of our machines (Automation Direct D2-260 CPU, H2-ECOM100 ethernet module talking with 2 local C-more HMIs (poll time of 500ms) and our automation network) is doing strange things that repeatably go away whenever we disable the device in the Ignition gateway.

After I add the device (Modbus TPC) to the gateway, as soon as I add a tag from the PLC into the Ignition tag browser under the ‘Default’ tag group, the C-more panels show a ‘PLC communication Timeout’ and the controls from them become incredibly unreliable making the machine unusable - even if the tag is deleted from the tag browser. Each time we disable the device in the gateway, the problem goes away.

I have no issues with any of the other PLCs I am doing the same thing with…

  • We replaced the Ethernet module - no change.
  • We upgraded the firmware on the C-more panels - no change.
  • I noticed that if I add a new device to the gateway and drag the [diagnostics] from the OPC browser I have no issues. But as soon as I add one tag the Requests/Average Duration goes from 0 to ~500 and the issues start again - other connected PLCs don’t often go much higher than 50…
  • I had added a few tags from this PLC on the 5th of this month - no issue. We upgraded from V7.9.9 to V8.0.2 on the 8th of this month and then upgraded to V8.0.3 on the 13th. This machine runs daily and the issues only started on the 16th…
  • I am going to replace the CPU tomorrow morning.

Anyone seen something like this or has ideas - would be much appreciated.

Is it possible these devices don’t allow more than one or two connections at a time? Or otherwise don’t function correctly when you’ve exceeded the connection limit?

I don’t believe so…

Well, empirical evidence is suggesting otherwise…

Can you get a Wireshark capture of comms between Ignition and the device? Start the capture with no tags subscribed, then add a single tag and wait until you observe the comms get weird on the other HMIs, then delete the tag, then disable the device.

We can at least try to verify nothing strange is going on.

This morning I updated the Ethernet module’s firmware, re-enabled the device that had several tags in the tag browser. The Diagnostics/Requests/Average Duration is now similar to other similar devices and I have not yet seen the ‘PLC Communication Timeout’ on either local C-more HMIs. Will update and try what you have suggested if anything changes but looks like we are back in business.


Great, thanks for the update.