False Cleared and Acknowledged Alarm

Ignition
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1

Perspective - Ignition 8.1.18

I’ve noticed the act of creating or modifying certain alarms has caused them to trigger despite never being in alarm condition. After editing an alarm, a cleared and acknowledged state alarm will generate. The alarm was never in an active or unacknowledged state before this.

Background Information
The alarm is based on a derived tag that uses a case structure in the read expression:

case({source},1,"String1",2,"String2","String3")

The alarm uses the “On Condition” mode with a string comparison in the “Is Active” expression binding:

{value}="String1"

The alarm operates as expected after the first erroneous alarm is generated.

Is this false alarm expected behavior? Is this a known bug? Do the expression bindings somehow leave room for a momentary true command?

Thanks for any assistance!

2

The same alarm behavior has also been witnessed with simple boolean tags; it doesn't look like it's an issue with the expression logic. Root cause is still unknown...

3

I haven't noticed any issues, especially using simple boolean tags. The default alarm mode setpoint is 0, so if you didn't change to 1 and saved and the tag is low, of course you will see an alarm.

4

Here's another post about the same issue.
@Jaron_Hafso Hi! I think its just an Ignition thing. I don't believe is is actually activating.