Limitation of compactrio,Problems of slow sample rate

[Zion]

I am using CompactRio 9004 which have Real Time module and FPGA. FPGA can run as fast as 40MHz.  Now I have a control programme which has to be run at least high than 500Hz. I compiled the whole programme in FPGA module and it worked quite well. But the problem is it takes me 1hr to compile the programme in FPGA and the programme needs to be modified frequently under development. So it is impossible for me to take 1 hr everytime I made subtle changes in the programme.

Then I have tried to run the programme in my computer (2 GB ram) which is connected to the CompactRio with an ethernet cable and takes 6 Input/Output from CompactRio (4 digital output and 2 analogue input). So the signal comes from the  Input/Output of the CompactRio  to a FPGA programme then go to my computer for my control programme. It takes about 6-7 ms for a loop in my programme in my computer which is about 130Hz. Therefore it is not fast enough.

One more thing is I find that the more the I/O used from FPGA to my computer, the more time it takes to run the programme. It take 1ms for one I/O and 6-7 ms for six I/Os.

I have tried to use Timed Loop to force it to my programme to at 2ms but the my computer cannot go that fast.

I have also tried to run it in Real time module in the CompactRio but the loop time takes even longer than that in my computer.

So is there any solution for this problem?

[xseadog]

Hi Zion,

I would hazard a guess that the problem lies in your actual computer set up !

What are the specs of your computer?

Is it a dual processor ?

Are you attenpting to multi thread ( ie have more than one programme open at the same time)?

What version of Labview are you running, 8.2.1?

Usually I find that it takes ~20 minutes to compile

Hope that helps


xseadog