Why Do I Have an Invalid Clock for My DMA FIFO in LabVIEW?

Updated Oct 29, 2019

Reported In

Software

  • LabVIEW
  • LabVIEW FPGA Module

Issue Details

I have a FPGA VI that uses some DMA FIFOs.
When I try to compile the VI, I have this error:

What can I do to fix this error?

Solution

The issue comes from the FIFO method you use in the VI.
If you use the Get Number of Elements to Write method, you must use the FIFO.Write method after.
Otherwise, you will get the previous error.

Additional Information

The error comes from the time domain of the method. If you use theĀ Get Number of Elements to Write method without the Write method, LabVIEW does not know the time domain of the Write method so he displays this error. This error is explained in the help of the method:


By adding this method in your VI, you force LabVIEW to define the clock of the method (the same than your loop).