Timer Function in Perspective

Ignition
1

When a tag value changes, I need an image component to become visible. After five seconds, I need it to turn off. Please help!

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2

In the view custom properties of the view containing that image component, create a custom prop for the tag value (with binding to the tag), and another for the most recent change timestamp. In a change script attached to the custom prop for the tag value, make this assignment:

self.view.custom.tagChangedTS = system.date.now()

On the image component, bind to props.visible with this expression:

now(500) < addSeconds({view.custom.tagChangedTS}, 5)

If you are using my Integration Toolkit, and want the expression to use no CPU time when inactive, use this variation:

transform(
	asList(
		now(0),
		addSeconds({view.custom.tagChangedTS}, 5)
	),
	transform(
		value()[0] < value()[1],
		asList(
			value(), // The real return boolean value
			now(if(value(), 250, 0)) // Trick to make the expression poll when true
		)[0]
	)
)

( I hate leaving polling functions running uselessly, but I want them to run quickly when needed. )

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