I have a 'double' data type tag which has a format of 2 decimal places, which has an 'Above Setpoint' alarm enabled.
When the tag has a value of 22.68 and I set an alarm threshold of 20.5, the alarm appears in the Perspective Alarm Status table.
The tag itself shows a trigger value of 23.4 in its alarm EventValue property, however in the Perspective Alarm Status table object the 'Event Value' column for the alarm displays a value of 23.399999618530273
Is this correct behaviour for the Event Value column, or is there a way of formatting data in the Event Value column to show only 2 decimal places?
I had an idea on this. I'm not sure how practical it is for your usage case, but I was able to achieve the desired effect by moving the alarm to a derived tag or an expression tag.
Actual event value = 82.687545776
TestTag01 has the raw value and TestTag02 has the expression value
Both alarms have the same trigger value, but TestTag02 displays with only two decimal places.
Here is how that looks in a derived tag:
Very neat idea!
My tag was originally a reference tag (pointing to an MQTT Engine tag), so I changed it to a derived tag and applied the read expression exactly as shown, and now it works!
I'm a little disappointed not to get any official response from IA as to whether the alarm object display should respect the source tag formatting for displaying data, but am happy I have a neat workaround.