Random Tags Not Working


I am trying to figure out what happened to my system last night. I have a position tracking tag for positions on a conveyor. I am using a UDT so all the tags are the same as far as structure goes, some work some don’t. I can not seem to understand what would cause this and how to fix this? They are all working in the PLC so I am not sure what caused this.

If you are in client what do you see if you use Diagnostics → Log Viewer, you should see warnings or errors regarding tags.

If you are in designer, what do you see if your right click a problematic component and select “Run Diagnostics”

Just a bunch of items showing “Error_Configuration” which does not really make sense since these are same UDT and coming from the same spot in the PLC. This happened out of nowhere too. This was interesting to me though. Let me know if any of this seems like it could be root cause.

This morning I reset Gateway with Gateway Command Utility, powered off the PC running ignition, etc. Nothing seems to want to make this work.

Another interesting note is that I noticed the components not working shifted one time. As you can see in the first picture of this post, position 3, 4, and 5 are not working but sometime today 3 and 4 started working…now they are all broken again lol

Are the working and non-working tags all from the same PLC? Any chance of a network/ip change or even tag changes within the PLC by another engineer who didn’t know they were being used by your vision application?

When you look at the tags in your tag browser in Designer do you see values or are they error’d out there as well? Are you able to find the affected tag via the tag Browser to confirm it’s still there on the PLC?

Yes they are the same because they are a structure, unfortunately there is no chance of a change like that. The tags in the browser were broken too. I actually found a fix today, maybe you could explain why this works to me…One OPC connection seems like it should be able to handle all my tags, but after some experimenting I found one OPC connection, only using these tags worked up until the 76th tag. After that, I created a new OPC connection (new name but same endpoint as previous OPC mentioned), then I continued on from 77th tag to the 152nd tag (another 76 tags)…and so on. Took a total of 10 OPC connections all looking at the same endpoint to clear all errors on these tags…This does not make sense to me, maybe you or someone else on the forum can explain this to me and if there is any way around it.

Some servers out there are lame, is all. There’s no limit within Ignition.

Troubleshooting here: OPC Connection Tag Limit? - #3 by jbpingston

Missed this thread and now it feels too late to merge.

Sorry for being all over the place, I was in a rush for answers lol

I now understand this all too well