Write array to FIFO and then split array array elements to multiple output channels question

[soljiang]

I'd like to send an array to FIFO using FPGA PCI7833R.

Then I'm using four output channels

Channel 1's output should be element # 0, 4, 8, 2n

Channel 2's output should be element #1, 5, 9, 2n+1

Channel 3's output should be element #2,6,10,2n+2

Channel 4's output should be element #3,7, 11,2n+3

However, after first iteration, the while loop stops and tells there's Invoke Method error.  

I attached both the vi's.  

Could someone tell me what's wrong with the program?  Thank you.

[soljiang]

In essence, my question is how to write four different waveforms to four analogue output channels with only one FIFO.  (There are only three FIFO availalbe on FPGA PCI7833R)

Thank you very much.

[Spectre_Dave]

I use a single DMA FIFO to push the data from the Host to the FPGA then I use eight Memory blocks to drive the individual Analog outputs.

Remember that You can NOT write the Analog Outputs any faster than 1MHz

[Drew_T]

soljiang,

I think that the error may be arising from the fact that you are reconfiguring the depth of the FIFO in the loop.  Is there a reason you need to do this?

Try removing the configure inside the while loop.  If it runs more than one cycle, there is your problem.  

I haven't been able to test this, but if you have a need for changing the depth mid stream, you may try starting the FIFO again once you have configured it.