Tag problems

I’m working on a quick screen to simulate a process I’ve written in RSLogix 5000.

As you can see, I’m using a user defined datatype called “BELT_CONTROL” for every tag used in this simulation. Using the OPC browser, I dragged and dropped the entire folder to my tag list in Ignition. That is folders “BELT1” and “BELT2.”

It appears as if some of the tags are linking to the PLC properly (all of the tags in “BELT1” folder), however a select few in the folder “BELT2” have a green question mark and are not reading values from the PLC.

Other misc. info:
I’m using the latest stable version of Ignition.
ControlLogix PLC
On the Ignition configuration page, the PLC says “Protocol: EIP,” which I have not seen before.

Thank you

Please excuse the huge image.

Does disabling and re-enabling the tags change anything? Or do they alway stay “unknown”?


I just tried that. It stayed unknown.

What version of Ignition are you using?

Try upgrading to 7.2.6-beta1. we just made some fixes that could possibly cause what you are seeing. After upgrading, be sure to click “refresh browse” for the device.

Thank you.

When can I expect 7.2.6 to be released as a stable version? I’m hesitant to upgrade to a beta version because the plant will be going live between 1 and 2 months from now.

I updated the Ignition software to 7.2.6 and I still have the same problem.

We have probably ~1000 tags at this point, and this is the only place we’re experiencing this problem.

Did you ever find a solution to this as I am having a similar problem?

Thanks beta 7 took care of the issue.

We are facing a similar problem using version 7.3.1.
Could be very usefull if you can share with us how you resolved this problem.
I attached an image with the problem… some tags are ok and others are bad, if we scan independently _Eqp_120_S_Bits2 it fix the problem for this tag and the nexts. But if we erased it, the problem continue.

This may sound weird… change the scan class on the tag, then re-open and change it back to what it was. The other thing I did was disable and then re-enable the PLC. One of them 2 seemed to fix it but do not remember which it was.

I just did both and I get the same problem.
We found a way to fix it, but we don’t want to do this on this way. We created a new tag and moved from the OPC Browser to SQL Browser only the first tag on the list with green question mark, ie, “_Eqp_120” (all the structure)… this tag is updated Ok… and the green question mark in the list dissapeared for all the next tags, from _Eqp_120 to _Eqp_125… but when we erased the _Eqp_120 tag the green questions marks appear again…

Thanks for your help!!!

We had another report of the same issue. I’m trying to reproduce the problem in-house so that we can resolve the issue. I’ll post on this thread when I have more information.

I resolved the issue and it will be included in the next maintenance release. If you are running into this problem and can’t wait for the next maintenance release, please email support@inductiveautomation.com and refer to this posting and we’ll send you an updated AB driver module.

I’ve run into this issue today myself, but I believe Ignition was installed 2+ years ago before I started working here, so I’d think that this would have been repaired by the time it was installed.

Similar to the stories above, I was working on a project that has several tags I refer to. All of a sudden today, the tags stopped updating and when I deleted and added them back, the tag came back as null even though I dragged the tag directly out of the OPC Browser. I cycled power to the laptop, deleted and reinstalled the PLC (CompactLogix L33ER) in the Gateway. The PLC is online and updating the tags, the Gateway confirms that the PLC is connected but the tags are now coming up null, is there a solution for this?

Verify the firmware on the PLC matches the selected driver for it on the gateway.
My guess would be they upgraded firmware on the PLC past version 21, so now you will need to redo the device connection with the other Logix Driver.


Thanks for the reply! I ended up adding additional tags in the PLC and had the tags that was originally in the Designer point to those which it allowed.