11-18-2012 09:52 PM
Hi there.
My company recently purchased some NI CompactRIO devices.
I have a product that output analog signals for voltage and current.
When the product is programmed to a specific voltage and current, I would like to record how long it takes for the voltage and current to stabilize.
The startup time should usually ranges between 800ms and 1100ms.
Right now I am using DAQmx to trigger data acquisition on a digital edge and then graph it. That works just fine.
My question is how can I start a timer when data acquisiton starts and then stop the timer after the voltage has stabilized (i.e. after 500 stable sample points).
My code is based off one of the NI examples so it very basic. I have attached my VI.
I know there are counter/timers available but I'm not sure how to implement this. And I dont know how I would display on the x-axis of my graph the startup time in milliseconds.
Any advice or tips would be greatly appreciated! Thank you!
What I have:
cDAQ-9174 CompactDAQ chassis (4 slot USB)
NI9205 32-Channel Analog Input Module
NI9264 16-Channel Analog Output Module
NI9401 8-Channel Digital IO Module
11-19-2012 03:19 PM - edited 11-19-2012 03:19 PM
Hello, take a look at the attach VI from this community example. Make your stabilized voltage/current level the stop condition for the loop to obtain the elapsed time. I hope this works for you
11-20-2012 11:10 AM
thanks for the information, it does help. I was wondering if I could the same with DAQmx VI's and compactRIO?
11-20-2012 12:07 PM
Unfortunately DAQmx and CompactRIO don't mix, however, the idea for the bechmarking remains the same indifferent to the programming.
11-20-2012 08:25 PM
ok.thanks. How would I tie in the time into my graph?Is there a way?