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Simultaneous measurement in two channel of NI 4772 in Labview

Hi, I'd like to measure acoustic signal with PXI-4772 and acoustic sensors.

I made data acacqusition VI like the attached figure. I use 3 channel in a device.

Channel 0 is connected directly to function generator and used for analog trigger.

Channel 1 and 2 are connected to acoustic sensors and acquire the acoustic data.

Function generator is also connected to acoustic source sensor and generates source burst signal.

My problem is that all signals measured channel 0,1 and 2 arrive at a same time.

This is not physical because acoustic source stays away from two receivers .

If trigger signal's measured from 0 sec, other signals must be measured with positive time

delay. But, in waveform graph or data, all signals arrive at the same time.

What am I doing wrong? Please give me advice. Thank you.

 

Ken, 

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Check your graphs. Right click and see if you have 'Ignore Time Stamp' checked.

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Hi,

Option of 'ignore time stamp' didn't affect my result.

I attach the figure of front panel.

If it works well, there is time delay of 0.0015 sec between the trigger signal and the measured signal.

Anyway, thank you for your reply. 

 

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