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Acquire signal with constant phase in daqmx with external source

Note: Posted the same in the Global Forum. Click Acquire signal with constant phase in daqmx with external source

 

Hello Mates,

 

I am facing a problem in acquiring the signal (known signal) with a constant phase in continuous acquiring mode.

 

For example, my source is an external arbitrary generator with signal parameters of 10kHz frequency with a 2V amplitude and 0 deg phase.

I have connected this source to my DAQ card and trying to acquire the signal with a constant phase in every iteration. 

 

Problems:

1. While trying to acquire the signal in the loop rate with respect to the number of samples to read, I acquired (Waveform Sample) the value of each iteration with a different phase that doesn't have any repeated patterns. (I used the Extract Single Tone Information.vi function to get the signal parameters)

2. I tried by using Analog Input trigger with Level and phase can be achieved for one iteration (Analog Trigger outside the loop before Start) and which is not continuing the trigger from 2nd iteration. But if I changed the trigger option with the Analog trigger, signal start, Read and stop functions inside the loop and allows to run every time results with a constant phase (with 1deg tolerance may be a problem with my source-not verified) that consumes more time than usual and felt this is not the correct way of programming. 

 

I tried syncing the reference clock of AO and AI were, I have generated the same signal from AO and measured in AI with AO reference clock to AI. I achieved the exact phase in a continuous read method every time. 

 

Please guide me if anyone has suggestions/solutions.

 

Thanks in advance.

Boopathy Raja S

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