5122 digitizer continuous p2p streaming to FPGA FIFO

[gemballa]

Is it possible to continuously send samples from 5122 digitizer to FPGA FIFO trough P2P stream, until I stop it ? I saw niScope EX P2P Interleaved Data example and I used it as reference for my problem. My problem is that after some period 5122 stops writing to peer to peer FIFO which is on FlexRIO 7965R FPGA, so I got empty FIFO. I'm using software trigger.

Regards.

[stockson]

Dear Gemballa,

PXIe-5122 supports P2P streaming. Do you get any errors from the 5122?

You used this example - http://zone.ni.com/devzone/cda/epd/p/id/6370?

Best regards,

[gemballa]

Hi Mateusz, thank you for your answer. 

Yes, I used this example. I didn't get any error from 5122, it just stops writing to FIFO on FlexRIO. I think that triggering is problem. I would like to start acquisition and to write samples to FIFO on FlexRIO continuously, using P2P. How to set up 5122 for continuous sending samples to FIFO, until I stop it?

Regards.

[stockson]

Hi Gemballa,

the example you are using is not meant for continuous acquisition. I would suggest you to have a look at the continuous streaming examples that can be found in the Example Finder and redesign the code.

It is hard for me to say something more, since I don't know what exactly you did.

BR,

[Nathan-P]

Gemballa,

There isn't a triggering problem with the example code, its just designed to acquire 1 record from the digitizer and send the data across the P2P stream.  The reference trigger is what tells the digitizer to stop acquiring (once a trigger is recieved, acquire the post trigger samples and end).  To achieve what you want, you will need to setup your digitizer to stream continuously (not acquire one record), and setup the P2P stream.  

A good starting point would be the "niScope EX Fetch Forever.vi" example, which is found in the NI Example Finder. (Help >> Find Examples).  The following links are also really good articles discussing how P2P works:

http://www.ni.com/white-paper/10801/en

http://zone.ni.com/reference/en-XX/help/372831A-01/p2pstreamhelp/p2p_theory_of_operation/

There is also a TON of helpful information in the NI-Scope Help file, installed on your computer.  There are several sections on Peer-to-Peer so I would reccomend looking into those:

http://zone.ni.com/reference/en-XX/help/372831C-01/

I hope this helps!