How long has my machine been stopped?

Ignition
1

I should be able to figure this out but my head is a little muzzy today.

  • I have the machine status logged on-change in the default historian.
  • I want my Perspective view to display how long the machine has been stopped (when stopped and blank when running).
  • The tag’s history setting has its Max Time Between Samples set to 1 hour so there could be multiple stop records and we would need to retrieve the first to know how long the machine is stopped.

How can I retrieve this t_stamp value efficiently? I could create a tag binding and run a script transform to figure it out but I’d have to retrieve quite a lot of records to be sure that I got the first stop event. That doesn’t sound smart.
I can disable the visibility if the machine is running so that part is OK.

2

I prefer using a dedicated table for events, not tag history. Multiple sources can share the table using a source device column. Then use a conventional query the “TOP 1” or “LIMIT 1” record from the given source device using “ORDER BY t_stamp DESC”. The primary key should be t_stamp+source.

1 Like
3

If all you want to do is display the time the equipment has currently been down for, I would create a binding to the tags TimeStamp, then use an expression binding like
secondsBetween(now(), {view.custom.tagTimeStamp}).
I use this script in a project library and a transform to display the time values as a string

def convertSecondsToDisplayTime(seconds):
	minutes, seconds = divmod(seconds, 60)
	hours, minutes = divmod(minutes, 60)
	days, hours  = divmod(hours, 24)

	if days > 0 and hours > 1:
		display = '%d Day%s, %d Hr%s' %(days, 's' if days>1 else '', hours, 's' if hours>1 else '')
	elif days > 0:
		display = '%d Day%s' %(days, 's' if days>1 else '')
	elif hours > 0:
		display = '%d:%02d Hr%s' %(hours, minutes,'s' if hours > 1 else '')
	elif minutes > 0:
		display = '%d:%02d Min%s' %(minutes, seconds, 's' if minutes > 1 else '')
	else:
		display = '%d Sec' %seconds
	return display
4

That will do! I forgot that the timestamp doesn't get updated if the value hasn't changed.

Time since run-stop
Time since run-stop1000×195 18.8 KB

Now I'm just giving the time since the run status last changed state. Set the text color to CSS variable --success for elapsed run-time and --error for elapsed stop-time. Nice!

Thank you.

5

I modified your code as follows:

def format_seconds_to_hhmmss(seconds):
	minutes, seconds = divmod(seconds, 60)
	hours, minutes = divmod(minutes, 60)

	if hours:
		return "%1i:%02i:%02i" % (hours, minutes, seconds)
	elif minutes:
		return "%02i:%02i" % (minutes, seconds)
	else:
		return "%02i" % (seconds)

This results in the following:

                      27 s -->        27
                      95 s -->     01:35
                     120 s -->     02:00
                    3700 s -->   1:01:40
170 * 3600 + 2 * 60 + 13 s --> 170:02:13

So it handles more that 24 hours nicely.

Thanks for the inspiration.