Indirect address component writing default value to PLC

Here's the issue:

  1. there's a numericEntry component created as a library element.
  2. in this numericEntry compnent, there's a property called "value", set as InOut type.
  3. this property has a default setting as "12.33".
  4. this numeric entry is used used multiple time on the screen for control setpoint entry.
  5. when this component is called, it's using indirect tag to assign the "value" property.

Somehow, from time to time, some part of the setpoint list will be changed to 12.33 in the PLC.

I checked with local IA tech support. I have been advised to change the default value to "null". It may prevent writing PLC with default value, as "null" is invalid.
Another suggestion is to assign the tag path as property to this component instead of actual value, then in the component to assign value to the PLC directly using the tag path, this way, the layer of InOut "Value" parameter can be removed, which could be cause of this issue.

I would like to check from the forum to see whether it also happened to you guys?
What's the root cause of this issue?

I am using perspective, Ignition V8.19.

Definitely don't pass the value of the tag and all its associated properties (eng unit, format, etc.) into the View, this is not good design. Pass the tag path into the View, then you have the freedom to read whatever properties you might need, now and in the future.


Just notice something interesting.
Current the setup has not been updated due to amount of changes across the whole project.

But here's what is happening:

  1. this forced writing to PLC action takes place only when I open the view from the designer, happened only to perspective, not to vision.
  2. only when I switched to "NO read/write" mode on the designer before opening the view, can it prevents the forced writing action. If I choose "read only" mode on the designer, it will still force the default value to PLC. It may need IA to further investigate.


This sounds like #5433:

So, upgrade to v8.1.23 and see if you still have the problem.

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