Writing to an OPC tag from Expression Tag, or Client/Gateway Events

[pkhoshroo]

I want to be able to write to a boolean tag (an OPC tag) when the result of a boolean expression tag is true. How should I do that? I have a hard time understanding this. I went through different threads
This is my expression tag:

if ({[~]model.value}=1177, 1,:
  0
)

I tried to use the solution suggested here:

Expression Tag that Writes to OPC Address (PLC)

Also, diffSetpoint is not defined, so you’ll need to either assign a value, or hard code a value diffSetpoint = 100 if newValue.getValue() > diffSetpoint: or if newValue.getValue() > 100: Edit: just thinking through this a bit. If the tag that is triggering this event is an expression tag which results in a bool value then your script can be simplified if you only want to write to the tag on a true value: if newValue.getValue(): system.tag.writeBlocking(['[default]_Rkn031_900_/Atomiz…

if you only want to write to the tag on a true value:

if newValue.getValue():
    system.tag.writeBlocking(['[default]led.value'],[newValue.getValue()])

It did not work.

Note that:
I may have some instances that I have multiple true values in a row, so it is not going to be "true, false, true, false" instead the result of the expression tag is more of a "true, true, true, false" . not sure if I should use client tag change.