PLC to Ignition Interactions

[pturmel]

@Xander_Dawson-Fink

advantages to using the Gateway Tag Change Event

There are pros and cons. (Numerous discussions here on those.) But it is almost always preferable to system.util.invokeAsynchronous(). Starting new threads is a performance killer, and can run wild if you aren't careful.

Discussions like these (and more, if you tweak the search terms):

https://forum.inductiveautomation.com/search?q=gateway%20tag%20change%20event%20valueChange%20thread%20pool%20order%3Alatest

If you have a particular need for valueChange scripting, but also need to not block other tag events, study this topic and all of its links:

Java concurrent queue for tag change scripts

Continuing the discussion from [SOLVED] Are tag Value Changed scripts running asynchronously?: We've got code in our standard library that I need to log a value change on a tag and then associate various data points with that value change. The value is located in a UDT, and because this is part of our "standard" library we use for our customers, the number of tags is variable and quite possibly numerous so having a gateway tag event script isn't feasible for this solution. I was reading up on …