How to send a square wave to an RIＯ board Analog Output(AO)

[George_Regan_Lee]

Hello~

I have a question about how to send a square wave to an RIO board AO.

I'm using a NI PCIe-7851R board, and I want to output a sequential square wave by an analog output in this board. Because the operating system(OS) can not produce a high enough frequency square wave, I want to write an lower compute program to generate a square wave. In the lower compute program, amplitude,period and Number of Samples are as inputs or known, the program follows those information and generate the square wave. The OS program only call the FPGA  module and send the amplitude, period and the number of samples to the lower compute program. Here is my OS program and lower compute program. But when I run the OS program, the output voltage is always 0, can you tell me the errors and reasons?Thank you!

The lower computer program:

The lower computer program(true)The lower computer program(false)Here is my OS program.The OS program

[George_Regan_Lee]

The third picture's English Translation

[Eric1977]

Can you upload your VI?

[George_Regan_Lee]

OK. There is my project. It is my labview project. And I send the lower computer program VI and OS program VI alone.

[George_Regan_Lee · Accepted solution]

The FPGA program has no problem. But in host program, there is no delay time when the FPGA run, so in the host program, the FPGA will close and FPGA will not rum completely.