RT FIFO Array of Waveforms possible?

[ehrlich]

Hello,

I just started developing for a Real-Time PXI Controller. Currently, I just read out multiple analog inputs using DAQmx with "N Channels, N Samples". This gives me an array of waveforms as output.

Is there a way to pass this output into an RT FIFO to futher process the data in a non-deterministic loop? My problem right now is how to create the RT FIFO with the correct type. How would this type definition have to look like? Just creating an array of the required size with an empty waveform by default didn't do the trick.

Or is this just not possible since RT FIFOs only support 1D arrays? What would be a smart way then to get all the channel data out of the deterministic loop?

Thanks!

[Duffy2007]

Hello ehrlich,

it is not possible to use waveform with RT FIFO. You can transfer the values from the

deterministic loop to the not deterministic loop and then build the waveform.

To get the right timestamt you have to calculate it.

You can use the actual timestamp - aquired samples to get the right starting point.

I hope this helps, if not please let me know.

[ThiCop]

Hello Duffy,

As far as I know you can use Waveforms with RT FIFOs.

This also confirmed by the note in the Help:
http://zone.ni.com/reference/en-XX/help/370622K-01/lvrtvihelp/rtfifocreate/

The question however still remains if you should use them.

[ehrlich]

Actually, it is true, one can use waveforms in RT FIFOs but unfortunately not arrays of waveforms.

For future searches: The way I now solved my problem is by sending each waveform in my array through the RT FIFO individually and reconstructing the array on the receiver side.