Making an alarm on a value that rises "x" amount in "x" time

Ignition
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1

Is there a way to make an alarm happen if I have a value that rises more than, lets say 10, in 5 seconds?

Example, chilled water value is 65 degrees and if it rises to 75 degrees within 5 seconds it triggers an alarm.

2

You'd need to take the derivative of that signal, then put bounds on the derivative. Taking a derivative requires doing math with prior values. Just using previousValue and currentValue on a change event is an option, but tends to be jittery for most purposes.

I tend to use the recorder() function from my Integration Toolkit to have a well-defined, not quite short, sliding sample window in memory. And use first and last entries for the math, to have less jitter.

3

Thanks, I will see what I can do. Thats a good idea.

I take it the recorder() function isnt something I have access to?

4

Install my Integration Toolkit module. It's free. Has lots of stuff that's generally useful.

5

Will do sir.

6

@pturmel , this one right?
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1 Like
7

Yeah, I changed the name from Simulation Aids after ICC this year, by popular demand.