cRIO saving question

[charmand79]

Hi all,

I have a cRIO 9074 sampling and saving lots of data.. I have manage saving all my data (in binary format) with no problems at all. However, my problem is that because the amount of data being saved is very large, an experiment running for approx. one hour would completely fill the hard drive of the cRIO (around 300 MB). I therefore thought of chopping the data by downloading the data files to the local host PC every 10 minutes while simultaneously deleting each file from the cRIO hard drive. All this occurs while the RT process is running. It seems that the system cannot cope with this strategy as in some cases during download the RIO VI freezes and all control is being lost.

Apart from adding a larger hard drive (assuming that I can actually do that), is there any other, software based, way of coping with this situation?

Thanks a lot for your time,

Harry

[viScience]

If you have LV2010 then I would recommend Network Streams.

Otherwise you will need to create your own tcpip background task that is continuously streaming data from your rt target. 

[charmand79]

Sachsm,

thanks a lot for the reply. I have LV2009 therefore I cant make use of your first suggestion. Just as a guidance wrt to the TCPIP task, because my networking knowledge is generally very basic, I assume I would have to use the TCP open connection function. How will I actually transfer the files via the TCP connection, could you please point me to the correct function? Finally, is this going to be any quicker than the standard FTP?

Thanks a lot

[JK1 · Accepted solution]

Hi,

Transferring the data through TCP/IP will be more faster than transferring through FTP.  The basic difference lies in the fact that using TCP/IP you should transfer the data directly (like 2d array of acquired data, waveforms, strings etc.,) and not as a file like FTP.

So you have two options while using TCP/IP:

1.Transfer the data stored in the file (in cRIO) periodically

2. Transfer the live data to host with or without storing in cRIO. 

The Host would contain the logic to receive the data and store it into the file.

Take a look into the example vi: "C:\Program Files\National Instruments\LabVIEW 2009\examples\comm\TCP.llb\Data Server.vi and Data Client.vi" that gives good idea about TCP/IP communication.

Post back if any queries.

[charmand79]

JK1,

thanks a lot for the suggestion, that was pretty much what I was looking for.

Harry