Data from RT to FPGA

[zundap1970]

Hi all
I need to play a playback file (*.txt) on cRIO HW. The file contains several rows and 4 column (time, sensor 1,..., sensor 3) and its dimension could be big (also 250 MB).
So I need to trasfer data from RT to FPGA ( I suppose to move the file from PC to cRIO via ftp) and I think to use a FIFO (DMA).
Whit FIFO I can not use structured data as typedef, so I can not define a data of 4 elements and move it inside the fifo
The DMA can manage the I32 data type and it means che I need to pack the data in I32 and unpack on FPGA site.
Any suggestion to avoid this procedure?
I'd like to move the data, if not in data structure, at least in an array of 1 row and 4 columns.

Thanks

[alamanna]

Hi,

maybe these forum threads can give you some useful hints:

• RT to FPGA data transfer via DMA FIFO
• 2x (U32 x 256 arrays) from RT to FPGA, how to program?
• Data transfer from RT to FPGA using DMA FIFO
• Questions about passing array from RT to FPGA and using array in FPGA?

Regards,

Alessia

[zundap1970]

Hi,

thanks for the links.

I'm thinking to use 3 FIFO (from host to fpga) for the data. For the time  is not necessary because the sample time is Always the same and I set it into fpga loop.
What do you think of this solution?

I would to use "Read Waveforms from File" to generate the signal, but I I need to solve the error "Waveform data type file datalog type conflict." (code -1821). The input file is a file (*.txt) processed by Matlab from *.mat files. Have yuo find this error before?

Thanks

P

[alamanna · Accepted solution]

Hi,

I have never met the error message you get before, it seems to be fairly infrequent, and it should be related to an incompatibility between waveform data types. The only suggestion that comes to my mind is: instead of using the Read Waveforms from File VI, why don't you use the Read From Measurement File Express VI?

Regarding the solution you devised, I don't see why it shouldn't be OK.

Kind regards,

Alessia

P.S .: I have noticed you created a thread very similar to this one in the Italian forum. Do you mind if we continue the discussion in this thread?

[zundap1970]

Yes I've done also on Italian forum , apologize if  I have not broken the forum rules .

The error is due to the data type incoming in VI, the VI accepts only bin file and not a *.txt. The solution is to generate a wavefrom from txt, to do that I try to used "Scan form string" with %f format and seems work.

Thanks

P