When I have a tag with alarm setting and tag value is in alarm state, changing the tag quality from good to bad and return to good again( by disconnecting and comnecting OPC UA) cause tag regenerate alarm even though user ack it before.
This very annoying for remote station with unstable radio link which cause to regenerate 100 of alarm each time link reconnect again.
Is there any workaround to disable this behavior?
What version are you on?
In 8.1 the OPC tags preserve their values and move to uncertain quality when the server goes offline. When it comes back online the quality goes back to good but the value remains the same unless it changed in the meantime. So unless you are using a quality or any change alarm it won’t trigger a new alarm.
In test this in 8.1.1. what I need is ignition doesn’t generate active unack alarm again after come back to good quality.
Please test this:
1 - create a boolean memory tag
2 - define an alarm on it
3 - change tag value to alarm state
4 - ack it and don’t change value to keep tag in active state
5 - change tag to opc to make it bad quality
6 - change tag to memory again
Now I will see another acitve Unack alarm generated which is annoying in some situations.
I need some option to disable in in alarm config.
Your steps where you actually change the tag type aren’t representative of the real world.
I have set up this scenario but instead restart the remote OPC UA server and there is no additional alarm event.
edit: There is some room for variation depending on how the particular OPC UA server behaves. In this case it does not send any kind of empty/initial value before sending the good quality value when the subscription is made.
Thanks, you are right it seems this problem is for 8.0.xx and fix in 8.1.1. I test by kepware and it works.
By the way this is also happened for historian. What I mean if the tag quality change to bad and come back to good the historian make a record of it. So each time the connection lost and back I see repeated record in history. The history detect quality good is a change to record tag value which is not desire.
Is there any way to prevent this?
Note: I set my tag to OnChange mode for history.
Most people want this behavior. The quality changing is a significant event.
It doesn’t seem like there’s any way to change this behavior right now, but making a feature request for it on the ideas portal seems reasonable.
This is specially needed with unstable radio connection which connect and disconnect time to time.