how to make continuous data acquisition using compactRIO NI 9237

[hema]

Hi
 
I have 2 doubts. The first is that i am measuring force using load cell connected to NI 9237 and compactRIO controller is NI 9104.
I have run the example VI which is found in the CompactRIO /module specific 9327 Getting Started project.
When i run the host VI, the VI just runs once and stops. that is it gives 4095 samples which is specified in the VI . So when i apply force, i see the 4095 values in one shot and the VI stops. I want the VI to run continuously. I should be able to see the values changing as the force is varied. how should i do this.
 
Secondly, i have to integrate this cRIO NI 9237 with NI  cRIO NI 9215 (9215 reads from LVDT) . Shoould I use just one FPGA target VI and call both module Analog inputs in the same place/sequence. or should the AI nodes be place in different places.
 
i am new to LabVIEW Real Time, so i need some info on the interrupt and synchronization part , any info links on this would help.
 
 
thank you, Hema 

[hema]

Hi Yi Ya,
Thank you. I put in while loop and am getting continuos data. I have to integrate NI 9237(measuring force) and NI 9215(measuring position) cRIO modules in my FPGA VI. I want to put both module analog node in common while loop and set update time as common. Can that be done? I also want to store the data that is read from both modules and store them in a text file with Timestamp. I want to read from the file and plot the two graphs. Do i have to use FIFOs for this? The data storing in File and plotting should not  be affecting the acquistion rate of the modules. how to do this.
thanks a lot.
Hema
 
 
 

[Meghan M]

Hi Hema,
You can integrate both your NI 9237 and your NI 9215 in one FPGA VI.  Once you add both of your modules and FPGA I/O to your project, they should both appear when editing an FPGA I/O node on your FPGA VI. 
The best way to store your data to a text file with timestamps would be to write your data to a shared variable in a high-priority acquistion task, and then read your data from the shared variable and write it to a text file in a low-priority acquisition task (See Figure 12 of the first article linked below). 
<a>FPGA Design, Development and Programming Tutorial</a>
I would also recommend that you use a DMA FIFO to transfer&nbsp;your data efficiently.&nbsp; Please read the Developer Zone article&nbsp;below for more detailed information on using DMA FIFOs, in addition to LabVIEW Help.&nbsp; Thanks!
<a>Using DMA FIFO to Develop High-Speed Data Acquistion Applications for Reconfigurable I/O Devices</a>
Meghan M.