Jump to content

FPGA vi ignores value of some front panel controls


elyness

Recommended Posts

I have found what seem to be very serious bugs with labVIEW FPGA. Has anyone else run into this?

I have a system that uses 4 7811R RIO I/o Boards. Each board has some similar tasks and some different tasks. I wanted to have a single program that I downloaded to each in order to save compile time. So I had front panel boolean controls to enable or disable parts of the code. The host program would configure the state of the controls before running the FPGA vi.

In emulator mode, everything was fine. But in device mode, my program produced no output whatsoever. It turned out that the boolean controls that enabled parts of the code were always false. When I hardwired a constant, everything worked except that now I had unique programs for each of the 4 RIO boards. Since it takes almost an hour to compile each one, this is a real pain.

Later I discovered another even more startling bug. One subvi was used in three of the FPGA programs. A front panel integer control defined its operation. The value for this integer orginated in the host, was set on the top level FPGA vi and passed through wires to the subvi. Again this worked fine in emulator mode. In device mode I got nothing at all. Finally I found that the value of the control on the subvi was always 0 not matter what I set on the top level VI. When I replaced it with a constant, it worked perfectly. I looked at the code extremely careful and added debugging to make sure there wasn't something I was doing wrong. But I was doing everything right and since it worked in emulator mode, I'm left with a baffling bug in labview FPGA. Oddly, other values are passed to the same subvi and tthey arrive as expected.

Anyone seen this?

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.