An error was detected in the communication between the host computer and the FPGA target

[solarsd]

Hi,

I get the following error while trying to run several FPGA VIs directly, i.e. by opening the front panel of the Target VI and clicking "Run". I've tried restarting the computer, recompiling and moving the source file to a different folder and the recompiling. Even the digital output example VI fails to run. Any ideas?

Regards,

Lukas

[Dave-C]

Hi Lukas,

You mentioned that this occurs when you try to run these VIs directly.  Does this also occur when they are called programatically?  Since this appears to be occurring at run-time, I assume this is a LabVIEW error.  Is there an error code associated with the message?  I'm not having success in finding related items from the text of the message.  Are other example programs also failing?  Is this on the same 7831R card we were talking about previously?

Sorry for the bombardment of questions.  Figured it'd be best to ask them all at once.

Regards,

-Dave C

[solarsd]

Hi Dave, When running the VI programatically no errors are reported, although I can't verify that the digital output values actually change, i.e. that the example actually works. I'll be able to do that next week. The error I am getting by running the VI directly does not contain an error code (I've attached a screenshot of the error window). At least two FPGA VIs are exhibiting this behaviour and yes, this is the same card. Regards, Lukas

[Dave-C]

Hi Lukas,

While I feel a little foolish asking, have you tried recompiling the VI or changing anything on the block diagram since first seeing this error?  If not, please try either or both of those steps.  Also, is this the error dialog you're seeing?

Regards,

-Dave C

[solarsd]

Hi Dave,

Sorry for the delay. The error box I'm getting is similar, albeit without the error code, just the message.

I've tried recompiling the VIs and sometimes it helps, but sometimes neither rearranging the block diagram (i.e. making fake "changes") nor moving files around and then recompiling helps - and to complicate matters the same VIs run OK the next day. There are several such "solutions" mentioned in some other posts relating to this error, but neither of them seems to work.

Did anyone else experienced such behavior and managed to solve this problem? Frankly, it is getting rather ridiculous.

Regards,

Lukas

[Dave-C]

Hello Lukas,

Is there anything that changes in the setup between those two days?  Once a compilation works, what is causing a need for another compile?

I'm also curious, when this does work, what is the space usage on the FPGA? I'm wondering if we're having an issue with the size of the file compared to the FPGA size.

Regards,

-Dave C

[solarsd]

Hi Dave,

I am not making any changes to the VI or the bitfile. What I am trying to say that this error seems to have an intermittent character too - sometimes it goes away even if I dont do anything at all. An example bitfile size is 540 kB, but I am not sure how to compare this with the FPGA specificiations: it has 10240 Flip-flops, 10240 4b LUTs, 40 18x18 multipliers and 720 kb embedded block RAM (Virtex-II V1000 in PCI-7831R). Well, does it fit? <:

Lukas

[Dave-C]

Hi Lukas,

Does this behavior occur with any other VI's or any examples?  I'd also be curious if this could have something to do with the PCI bus/port on the computer.  I know it's cumbersome, but have you tried switching to a different PCI port on the machine to see if the behavior persists?  As far as the size, I was curious about the FPGA percentage used, but I'm fairly certain that isn't a factor here since we would be seeing a compilation error that describes that.  So, yes, it fits since it will run at least on occasion.

Regards,

-Dave C

[solarsd]

Hi Dave,

As mentioned, this occurs, it seems, with almost any VI, example or not, simple or complicated. I think there might be something wrong with the PCI bus too, I am not 100% sure (I need to do some further testing) but it seems that power cycling the computer helps to resolve this issue. And by power cycling I mean turn off the computer, switch off the PSU (using the hard switch on the back), wait ~10s, and boot back up, simply rebooting does _not_ do the trick. I know this solution seems rather silly, but it seems to help every time this problem arises. I'll do some more testing and write down the steps properly to confirm.

As for the PCI port trick, I'll see if can shuffle the cards around - being a measurement computer it has either all slots full or some other big cards obstructing any additional ports.

Regards,

Lukas

[Dave-C]

Hi Lukas,

If that power cycling procedure works to reset the conditions, that's furthering my belief that this is related to the PCI bus or slot.  This is also being aided by the fact that this is occurring with multiple VIs and examples.  Let me know if you get a chance to try a different slot in the computer.  Could you also let me know what version of the NI-RIO driver you're using?  

Regards,

-Dave C