Calculate the Duration after Toggle switch turns on

Ignition
1

I was thinking to use Tag.Timestamp property of a Boolean memory tag "NotScheduled" as starttime and now() as current time to get the difference.
This script appears to work half way, when I set another integer type memory tag "notScheduledTime" the tag value to 100 and run this, it changes to 0, I think the else logic part appears to work. But it was not updating the tag with duration minutes.
I would appreciate your help.

image
image458×405 30.9 KB

def valueChanged(tag, tagPath, previousValue, currentValue, initialChange, missedEvents):

	import system
	# Define tag paths
	durationTag = ["[.]../Performance/notScheduledTime"]
		
	if 	currentValue.value == True:
		currentTime = system.date.now()
		startTime = currentValue.timestamp
		minutes = system.date.minutesBetween(startTime,currentTime)
		
		if minutes >=1:
			minutes += 1
		system.tag.writeBlocking(["[.]../Performance/notScheduledTime"], [minutes])
	else:
	    # when toggled to False, reset duration to zero
	    system.tag.writeBlocking(["[.]../Performance/notScheduledTime"], [0])
2
  1. Don't import system. It's built in.
  2. Don't run scripts like this on tag value changed. There is a limited pool of threads (3) and system.tag.writeBlocking can gum it up.

Always, if you can, use an expression rather than a script. Try this expression in notScheduled:

round(
	(now() - {[~]notScheduledTime.Timestamp}) / 60000,
	0
)

While you test it out set the Data Type to Float and round() to three decimal places so you don't have to wait a minute to see the change.

The expression will update at the default scan class rate. If every 5 s is good enough then change now() to now(5000), etc.

1 Like
3

Use minutesBetween in your expression.

if([~]Performance/notScheduledTime,
   minutesBetween([~]Performance/notScheduledTime.Timestamp, now()),
   0)
2 Likes
4

@Transistor Thank you for highlighting the issues with my approach and suggesting alternatives.
@JordanCClark - thank you for simplified expression.

5

writeAsync is OK though, if you don't need to wait for it to write before continuing. Actually, writeBlocking is fine here too as it's writing to a memory tag