PitchNancy

The communication rate with interruption probably not exeed 1 Mo / s, it's very slow... What's your data sampling rate ?

:question: Do you think it's possible to do a "scroll graph" with 3D curve ?

My graph post data only point by point (with system of point by point acquisition. one loop, one point) .

What do you mean by "artefacts"?  Could it be that your counter is overflowing?  At 1kHz, a 40MHz counter reaches 40,000 if it starts at zero, approaching the 65,535 limit.

4609[/snapback]

Thanks, I did not think of this problem !!!

After correction I do not have any more insane peaks.

But now my problem is the limitation of the band-width by using IRQ. I don't understand why it's impossible to use DMA transfer.

Hi,

I use FPGA's counter input for PWM demodulation. My base PWM frequency is 1kHz. I use the tick count VI for the pulse width and period measurement. Tick count clock is 40 MHz, and 16 bit r

Hello,

With my pxi FPGA and RT 8186 controller I obtain only 20 kHZ of loop rate.  I use IRQ  method and acquire 8 analog input. I make for the moment no processing on FPGA and RT.

Can you say me if you have similar results or better ?

4057[/snapback]

Hi,

After doing some test I have a beginning of explication. I have used the real time system manager to evaluate the CPU usage. I have acquired 8 analog Input with FPGA and transmitted them to RT by the IRQ method. I did the test for cluster, array, and 8 single channel transmission.

After 20000 Hz the RT CPU usage was superior than 100 %, and bug. I attach my VI and my results.

Download File:post-1636-1109952736.zip

Download File:post-1636-1109952738.pdf

Hello,

With my pxi FPGA and RT 8186 controller I obtain only 20 kHZ of loop rate. I use IRQ method and acquire 8 analog input. I make for the moment no processing on FPGA and RT.

Can you say me if you have similar results or better ?