store data rate in CompactRio

[manyanez]

Hi:

    My name is Manuel and I'm from Chile. Well I wrote this message, because i have some problem whit my CompactRio 9012. In particular I have to save some data, whish are sampling at 50 KSamples/second. The problem is I have 2 loop, one for read from the FIFO FPGA, and the other to save the data in a binary file. The first work exellent, but the second, when i decide to save the data, work too slow, so the FIFO RT, who transfer the data from loop 1 to loop 2, is colapsed. I make some test, and I think the problem is in the data rate used for transfer the data between de Vi and the hard disk. Well I will be attentive to your answer.

Manuel Yáñez Molina

[preston_johnson]

Are you using DMA to transfer data from FPGA to RT?  The DMA read is blocking, so you need to put a wait in your RT read DMA loop.

[Christian_L]

Manuel,

To help you further we will need some additional information about your application and current code.

How many channels are you acquiring at 50 kHz? Are you scaling and calibrating the data in the RT controller before wiritng it to disk? What functions or VIs are you using to write the data to disk? Binary, ASCII?

If you can include a copy of your code that you use to read data from the FPGA to RT and to write it to disk, it would allow us to help you further.

[manyanez]

Hi Christian:

                 First too all, thanks for your help. Well, in this moment, I am icquiring 8 channels. I try to scale and calibrate the data  but the process make too slow the VI, so I save the data in a binary format. I  can´t let you a copy of my proyect, because it have too many subVi, and I try to put into a winrar file, but the discussion forum, doesn´t support this format. If you can send me a mail, it would wonderfall. Thanks for all.

Manuel Yáñez Molina
manyanez333@gmail.com

[Christian_L]

You can attach multiple files in a ZIP file, or you can attach just the main RT VI which communicates with the FPGA and stores the data to file. How are you passing data from the FPGA to RT?

[manyanez]

Christian:

               Sorry for the late, but I was too busy in my job. I let you the program in ZIP file. Thanks for all.