How to handle duplicate PLC tags?

We have some CompactLogix PLCs that each have similar tag structures. ie: tags with the same name

How do I handle that in Ignition?

In the SQL Tag Browser under Tags, I have created folders for each PLC. I can drag and drop the tags from each PLC into the proper folder.

This would be like:

I can use these to animate a window fine, but what do I do when it comes to a historical database?

When I try to put both in a single transaction group, it complains because the item names are the same.

What is the recommended way to handle this problem?

Is there a way to “alias” these names? Can I change the name of the tag, but leave the path to the tag the same?



Yes, you can change the name of the tag without changing the path. To do this, right-click on the item and select Edit. You can see that there is a field for ‘Name’ and a field for ‘OPC Item Path’.

I would change the name to PLC1_LastScanTime (and leave the OPC path alone). You also need to make sure the ‘Target Name’ field is different for each item or it will try to write to the same column in the database twice.