dear sirs, excuse my English, it is not my native language but I cannot get help from the forum in my tongue. I have folllowed 2 LABVIEW courses but have not been taught on DAQmx acquisition. I am using LABVIEW2011, a NI 6229 PCI card/CB68LP connector and I want to acquire an analog signal that should be considered as non periodic. A motor is spindling at 20Hz nominal with an uncertainty of 20%. 2 sensors ara attached to this motor and send digital signals : S1 -> 1 signal per rotation, reliable (f1~20Hz) S2 -> 1024 teeth in 1 one revolution (f2~1024*20Hz) but must consider missing teeth possibility The analog signal must be acquired during 20 or 40 periods (counter on S1) on each falling edges of S2 and I want to store each value with the corresponding time (relatively to the start of the acquisition) in microseconds and the counter index on S1. Is it possible to do so without switching to LABVIEW RT? I have succeeded in acquiring an analog signal from a function generator but am unable to go further. Any help would be welcome on DAQmx assistant configuration regarding those points : - should Dev1/ai0 analog be triggered by S1 or S2 PFI inputs, reference trigger? advanced timings parameters? - counter input/edge count on S1? - digital/line input for S2? Thanks in advance for your help, Pierre

The basic configuration (up to starting the task) would look like this: Task 2 and 3 are indeed very similar, one uses a PFI line for the source while the other uses the 80 MHz timebase (or whatever internal timebase you prefer). Best Regards,

Multifunction DAQ

aperiodic acquisition analog signal

Solved!

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dear John,

I have finally got in touch with NI engineers (PP) and here is the VI that seems to perform he required tasks. I hope it will help other people with needs similar to mine.

Best regards

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Multifunction DAQ

aperiodic acquisition analog signal

Re: aperiodic acquisition analog signal