'No Pending Request' after PLC power off

Not sure if its something wrong on my configuration or if its a potential bug. We had a AB PLC powered down on the line for some maintenance, and the logs started getting spammed with ‘No Pending Request’ messages. I went to the details page for the device, and it showed a significant load factor(I am guessing the max).

Disabling and re-enabling the device seems to have fixed the issue for now, but figured I’d post here in case there is something I can fix for next time, or if it is indeed a bug.

Seems weird, since that warning is about requests/responses between OPC UA client and server.

What version of Ignition is this? Do you have scripts doing explicit reads or a read mode scan class / tag group pointing at this device that went offline?

Version 8.0.7.

We do have a couple of gateway timer scripts that pull from a couple of tags, but they run at a much slower rate than those messages were appearing. Other than that, transaction groups are connecting to it.

Same thing happening here. Gateway gets flooded with this error whenever we power off the device (AB PLC). Any details/reason on why this happens is much appreciated.

Ignition version 8.0.16

If it’s reliably reproducible then you should call support and let them take a look. Maybe something will become clear with a Wireshark capture or some logging enabled.

Without more information I can’t see the link between these OPC UA related log messages and a device being offline. They shouldn’t be connected like that.

Which driver is being used in this case?

Thanks for the rapid response Kevin. The Allen-Bradley Logix Driver is what we’re using.