I have been told that there was an issue with large UDTs with several scan classes when interfacing with a Rockwell controller. Where the PLC has a single UDT, and Ignition tries to pull the tags at different scan classes.
So if my PLC UDT has 100 tags in it; and my Ignition UDT scans 20 of the tags in a 1 second scan class, 20 of the tags in a 10 second scan class, and doesn’t scan the remaining 60 tags from the PLC UDT.
How will ignition scan this?
When it scans the 20 1 second tags, will it pull just the 20 tags? or will it pull the whole ignition UDT (40 tags), or will it pull the whole PLC UDT of 100 tags?
This could be an issue with the PLC, but I would like to know if anyone knows of a similar issue, or could confirm the above issue.