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How to generate two quadrature signals with phase shift?



I am using NI PCI-6229 DAQ card. I need to generate two 2kHz quadrature signals with 90 degree phase shift using PFI channels. I couldn't find any example where the phase shift is added between signals.

Any help would be appreciated.





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There are different ways you can approach it.  The best choice will depend on whether there are further requirements or constraints.


1. DO.  Either finite or continuous.  You'll need to physically wire from the DO output pins to the desired PFI pins b/c hardware-timed DO can't be routed to PFI.   If continuous, you can define a small buffer and set the task to regenerate.


2. Counter output.  Define the two pulse trains with the same high and low time but different initial delay values to set the phase shift.  You'll need to sync the two counters to accomplish the desired phase, probably with a shared trigger.  You can then programmatically generate that trigger signal to control the timing.



-Kevin P

CAUTION! New LabVIEW adopters -- it's too late for me, but you *can* save yourself. The new subscription policy for LabVIEW puts NI's hand in your wallet for the rest of your working life. Are you sure you're *that* dedicated to LabVIEW? (Summary of my reasons in this post, part of a voluminous thread of mostly complaints starting here).
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Use two channels of one port and output in a loop 




with 8kHz AO samplerate 🙂



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