Expression tag syntax help

Ignition
1

Is it possible to assign a value to a tag based on a boolean in an expression tag?
if second_shift == 1:
{[.]P1_C_Target} = 0

2

Sounds like you should be using a tag change script instead.

1 Like
3

does ignition offer a one-shot? meaning it will only happen once when the tag changes

4

If you mean once for each change, then that's what tag change scripts do.

5

Sort of.

Tag change scripts run once per value change, timestamp change, or quality change, plus once during startup with a startup flag set (initialChange). The purpose of the startup event is for you to retrieve any state that would matter to you prior to that. The rest of the time, Ignition will give you one-shot behavior.