800xA 5.1 - Dynamic alarm message text or condition text in Alarm Expressions
Seems like the "Condition", "Subcondition" and "Message" fields in the Alarm Expression aspect are static. This is really unfortunate because I'm now forced to create a very large number of expressions for a single signal type (an integer), just to get the correct alarm message and condition for each state of my integer variable.
So is it a bad idea to have 50-60 expressions for each signal type? Eventually I'll have like 100 instances of these signal types, so I guess that implies that the soft alarm service will have to check 500-600 expressions all the time.
Bad idea? Alternatives? I cannot generate these alarms in a PLC unfortunately.
Voted best answer
500 alarm conditions delivered via the SoftAlarm Service and Alarm Expressions should be not be a problem.
Expressions are much less reliable than controller generic OPC AE alarms. OPC Data Quality is key factor as ”no data or bad quality = no alarm”. Timestamps will be no better than what the OPC DA server offer.