Ignition 8.1.14 running on windows server 2019.
Just wondering what is the best way to historise a bit within an integer “status” word when the tag is defined in a UDT.
Should I just add derived/expression tags (in the UDT definition) for each of the bits I’m interested in or is there a much better way of doing it?
If the source is OPC, I’d be inclined to add the bit reference to another OPC tag. If any other type, I’d use an expression tag.
I went with the expression tag as there are 20+ bits in the dint (6 of which need to be trended).
I imagine 20 OPC tags to bits of the DINT is more costly on comms than just reading the DINT once and creating expression tags (which I guess will depend on the grunt of the server processor)
No, OPC drivers are generally smart enough satisfy those together as long as they are subscribed at the same pace. That’s why I recommended it.
Useful information to know