how to get real -time timestamp for cRIO and FPGA VI data plot

[hema]

I am reading from cRIO NI 9215 and NI 9237 modules. i have integarted both the modules in one FPGA target VI. I have attached my program. The data from both the modules has to be plotted with timestamp.

how to do this.At the same time has to be saved to file on RT. please let me know whether my integartion of the two modules is correct. as well as how to plot two data with timestamp on x-axis.

i have a common loop rate of 20 micro secs for both modules.

Thank you.

[Erik_J]

Hi Hema,

Your integration of the two modues does look correct.  In order to plot your data with timestamps, you'll need to use the Get Timestamp VI in your RT code.  You should call this VI on the first iteration of the loop only to get the timestamp of the first sample.  This VI should be called at the same time your data is retreived from the FPGA.  You can do this using a Sequence Structure (see attached image for example).  You can then get the dt (time between each sample) using your Count variable, simply divide it by 1e6 to convert from microseconds to seconds (see attached image).  With the first timestamp (t0) and dt, you can now construct a waveform, and if you plot that waveform, it will show a timestamp for each sample (timestamp for sample n = t0 + n*dt).  Again, see attached image for an example.

In regards to saving data on the RT target, simply use any of the File I/O VIs in the File I/O palette.  These allow you to save spreadsheet, text, binary, TDMS, etc... type files to your RT target.  You can then ftp to your target to retreive those files.

Please let me know if you have any other questions, thanks!

Regards,
Erik J.
Applications Engineer
National Instruments

[Ashokan]

Hi,

I have to generate and store the jpg file in crio. The code works on my local PC. When I deploying the same in crio, it didn't work. It returns zero. Also I tried the paths like c:\test.jpg or /c/test.jpg; both didn't work. We are using Labview 2011 full professional development system.

cRIO 9025

Chasis 9113

NI 9229 

Thanks for the help.

ASAP.

Regards,

Ashokan