Alert on Any Change Question

Hey guys,

I am trying to figure out how the Alert on any change option in the alarm configuration works. From what I’m reading in the manual it will only send an alert on any change if the changed value is in the alarm range, is that true? If so that’s not how it seems to be working.

I have an alarm for a injection percentage calculation value tag. This tag changes maybe once every 5 to 10 minutes (when production does a test). I set up an alarm for anything over 112.5 and set alert on any change to true. Now it sends an e-mail when it changes from a good lower value to anything above 112.5 but then it will also send an e-mail when it changes from an alarm value to a good value (anything lower than 112.5) Does that sound correct? I would think if the new value is less than the alarm threshold then it should not send out a new e-mail. Or maybe I have it configured incorrectly?

Actually, I would guess it’s just sending a Clear message. Unfortunately, the same message gets used for active and clear, so if you don’t reference the “Alarm_Type” property, you won’t be able to tell the difference.

If you don’t want to send a clear message, you can turn it off. You probably didn’t know this, because I just realized… the header for that setting is getting truncated and its meaning lost! That’s right, “Alert Send” actually is short for “Alert Send Clear” (I don’t know why it’s not just “Send Clear”… we’ll have to modify that). So, if you change that to “false”, it won’t send clear messages for that alert. Try it and see if it helps your problem.


Alrighty, I’ll give that a shot. That’s set to true for all of my other alarms too but they don’t send a clear so I didn’t think it was that.

Does that option still work if you have the send clear option turned off in the Gateway configuration? That’s the other reason why I thought it was not working correctly, because I have the global send clear option turned off in the Gateway settings so I thought it shouldn’t send any clear messages.


Eh, I was taking a shot off the cuff. Now that I’ve looked into it, I think you’re right in your observation of how it works. Basically, the logic is really “any change in that range… including changing out of the range”. Whether or not this is correct is up for debate.

Ok, it’s probably not much of a debate. Is there any reason a message should be generated with an active flag when it’s not actually inside the range? Perhaps just a clear message would be appropriate. The way it is now, any time a message gets generated, if “any change” mode is selected, the active and cleared flags are always both set.

So, it looks like for now there’s probably nothing you can do. I suppose we should change it soon.