Quick simple question. Is it better to have multiple tags within UDT's or different tag folder structures reference the same PLC tag or is it better to have one OPC tag and the remaining tags be reference tags to the sole OPC tag? Is the driver smart enough to populate say three tags with the same value or, does the driver pack up the requested tag 3 times? I hope this makes sense and I may be over thinking this for sure. And is there any reason not to use reference tags? Thanks in advance
For pretty much all IA drivers, and my own, yes. Multiple tags pointing at the same PLC address will all be satisfied with a single PLC request. As long as all are using the same poll rate.
Reference tags break if you break the one source. OPC tags pointing at the same address will be independent of each other.