Hi. I have some UDTs with ‘disable-able’ subtags.
I have an expression tag I use to check for the highest alarm priority of any of these subtags.
When an alarm tag is disabled, I can read the value of that tag and my expression value turns to ‘disabled’. However, I would like to do a comparator, for example:
but it seems to just make the expression evaluate to ‘disabled’ regardless of the outcome of the logic. Is this a 'feature" or is there a way to do this? Thanks.
isGood() expression function;
disabled is the quality code being returned, which is the “worst” quality code of any part of your expression and therefore defines the overall return value.
How did you read the value of a disabled tag? i can only read null.
i have an tag that sets off a alarm. after the set time, the tag gets disabled. i want to read if this flag value even when the tag is disabled.
how can i do this?
can you please share the code in which you are able to read the alarm tag value .
I don’t think I was able to read the value of the alarm when it was disabled. It gets to the ‘primal’ nature of the tag and makes it completely evalute to DISABLED no matter what. Perhaps you could try disabling the alarm instead of the tag?