Tag change scripts firing when tag properties edited

Ignition
1

How can I prevent gateway tag change scripts from executing when the tag properties are edited? Conditioning with not initialChange and previousValue.value != currentValue.value is not effective. Thanks.

Ignition 7.9.8

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I created a tag ( Memory Tag ), used it as trigger for a tag change script ( inside Gateway Events Scripts ).
Inside my page I have a button that changes a property of this tag ( EngHigh ), but when I click it, no script is fired.
I tried all the combination for “Change Triggers” ( the options Value, Quality, Timestamp ) but still nothing.

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In case it’s not clear, try using Gateway Tag Change Event Scripts, not Tag Events. { There are many other good reasons, too. }

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Thanks, this is good information. This may be the case for scripted changes, but right-clicking on a tag to enter the tag editor and clicking OK (whether or not any changes have been made) will fire the tag change script.

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Thanks Phil. I have not noticed a difference and in fact in this case I am using a gateway event script triggered by a tag change (I should note that I have only selected ‘Value’ as the change trigger). Maybe this is not too big of an issue. It was only a problem for me after creating and re-assigning some scan classes which ultimately created a fair amount of bad data needing to be cleaned up. If there is a method to prevent this I would add it to my common script header.

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This is because the Tag gets refreshed. It’s something like its value goes from something (your value) to NULL to something (your value). This is seen as a value change so the scripting event will fire.

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This is a good point. Ok, so I achieved the result I wanted by adding the condition previousValue.value is not None and currentValue.value is not None. This prevents the tag change script from running when the tag editor is saved and closed.

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