Perspective binding executing two times consecutively

Ignition
1

I have a view and a custom variable which value I am updating by binding, expression with a tag value, and then script. What I notice. My tag value is updating one every 5 minutes (dataset tag) and binding on custom variable executing every time two times.
Is it a bug? Or I am doing something wrong?

Thanks!

2

Can you post a screenshot of the binding dialog? Also, what are you seeing to lead you to believe it’s evaluating the binding twice? Actually, are you claiming it’s evaluating twice each time the tag updates, or that it is only evaluating every other time the the tag changes? Is there one driving value for this property’s value, or is it dependent on changes to a binding AS WELL AS the value of a tag?

3

Thi is not the first time that I have this problem and this is not only case. I am fighting with this problem already few day. Custom variable is, for now, static, tag that I am using on event value change log message (that I am using to be sure that value isn’t changed two or more times).It’s evaluating twice each time the tag updates. In scripts below I don’t change value of the tag in expression.

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4

Your expression has two different values which drive it, so it will evaluate whenever either of them changes. I can’t see any of the script, but try these options:

  1. Verify that nothing in the script writes directly or by extension to either the tag or the custom property which are used in the expression.
  2. Instead of only logging “enter” as part of the script transform, try logging the values of the tag and the custom property. You’ll probably find that the value of one of them is changing. If the values aren’t changing, perhaps the timestamp of the tag is different? That might result in the expression evaluating because the Tag is no longer technically equal to what it was before.
  3. I’m not familiar with the view expression you are using. Is that a third-party expression? If so, you might want to contact the provider as they might be able to explain what you’re seeing.
5

That's mine. From Simulation Aids.

Note that writing the same string to this.custom.condition is still a change as far as the expression language is concerned. Don't do that if condition is unchanged.

1 Like
6

Condition will be changed. At the moment it’s static value.