03-16-2018 02:54 PM
Hello
In my application I do a AC Volt Measurement with a NI-DMM 4081 to measure values of a ECU between 30 µV and 100 µV.
I use Labview 2015 and latest DMM driver.
I attached 2 Screens of the ac configuration and the measurement VI.
DMM Config:
Range: -1 (Auto)
Digits: 6,5
Min Freq: 500Hz
Max Freq: 2kHz
Problem:
The Multi Point VI needs at least 6 seconds to acquire 10 Samples. That means a sample rate smaller than 1 S/s.
If I enable AutoZero and ADC it takes 60 seconds for 10 Samples.
Actually the goal is to add a lowpass filter behind the Multi Point VI. With this sample rate it's almost impossible to use a filter VI afterwards
because the filter VIs require a samplerate bigger than the cut-off frequency (500Hz).
I found this page http://www.ni.com/tutorial/6234/en/
According to this we can only reach a sample rate of 100 S/s with 6,5 Digits.
And yes I can see that AutoZero and ADC decreases the measurement speed if enabled.
But I didn't expect such a low sample rate of under 1 S/s.
Is there any possibility to improve the measurement speed? And to add a filter afterwards.
Thanks for any advice.
Greets
03-19-2018 06:31 AM
@shavo wrote:
Is there any possibility to improve the measurement speed?
Sure. Lower your resolution.
You are stuck in what every DMM and DAQ has to fight: accuracy vs speed.