I have a Driven scan class setup for Configuration tags that rarely need to be scanned for changes. (Anyone familiar with the AB PlantPAX AOI’s knows there are a lot of cfg tags that don’t need to be scanned all the time.)
It has a driving tag set to any change that will execute the scan.
I have tried this with 2 different scripts. Both work fantastically when tied to a button.
system.tag.scan("Scada", "ConfigChange")
PushTag = system.tag.read("PushConfigChngs").value
if PushTag:
system.tag.write("PushConfigChngs",0)
else:
system.tag.write("PushConfigChngs",1)
I’ve tried them both in the gateway startup script and neither one will cause the scan class to scan when the Gateway is started. The strange thing is, when using the second script, I can see that my driving tag did toggle states, but it just didn’t fire the scan. and my associated tags are all “null”
Is there some timing reason this will not work in the gateway startup script? Is there another way to scan this class once when the gateway is first started up?
Thanks