Causes of tag not matching plc

Ignition
1

PLC says one number
Ignition says a different number
Tag claims it is good quality
Published date is days ago

The infeed value is updating in both PLC and Ignition
The outfeed value is not updating in ignition or hasn’t since a few days ago.
The outfeed value is updating in the PLC.

CPU reads 69%, which I think might be the culprit, but it seems odd to impact this tag and not many others.

2

What PLC brand and series?
What firmware?
What driver?
Can you show screenshots of the PLC tags with values and the Ignition tag OPC path?

1 Like
3

Rockwell RS logix 16
not sure

I setup a new tag, and set it the same
It says last published value is uncertain with a date of June 30th 2022.
Thought that was odd.

I was able to write to the tag in the plc.
I could take some limited screenshots.
Is the fact it wrote to the plc adequate though?

4

I’ve stopped using rockwell.

Does RS logix 16 mean;
Ver 16 firmware? In which case you should be using the legacy driver

or

e.g. an L16ER compactlogix?

Or other?

Is this part of a UDT? Is external access (in the PLC) enabled on one tag and not the other?

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5

Did it use to work and suddenly stopped or has never worked?

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6

Someone with access to config on the gateway webpage reset the communication to the device and that tag is working now.

Thanks for helping me Matrix.
Sorry didn’t have answers faster.