USRP and "fusb: (rd status -71) Protocol error"

[stevie.glass]

Hi

I’ve a rev 3 USRP which has the Flex2400 and TVRX daughtercards
installed.
At one time the setup worked well - altho I’ve let it lie a while. This
week I’ve swapped out a TVRX and replaced it with the DBSRX in
preparation for a new project.

When I run usrp_fft.py things are fine for a few moments but inevitably
the program crashes with:

fusb: (rd status -71) Protocol error

repeatedly written to the terminal. Similar story for usrp_oscope.py and
most other examples.

This occurs both when using the Debian packages (3.0.2-2). When using
the latest subversion build I sometimes (once in every 4 or 5 runs) get
the error during the test_usrp_standard_rx “installation” stage but
otherwise it works and produces results such as:

xfered 1.34e+08 bytes in 4.19 seconds. 3.2e+07 bytes/sec. cpu time =
0.184
noverruns = 0

What is the “Protocol error” error caused by and how can I fix it?

Kind regards,

Steve

[stevie.glass]

On Thu, May 03, 2007 at 07:27:33AM +1000, stevie.glass wrote:

fusb: (rd status -71) Protocol error

repeatedly written to the terminal. Similar story for usrp_oscope.py and
most other examples.

I have in the past seen this, but mostly when I’ve powered down a USRP
while the application was still running.

You may want to try a different USB cable. It might be flaky.

Eric

[stevie.glass]

Eric B. wrote:

the program crashes with:
You may want to try a different USB cable. It might be flaky.

Eric

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Could this be related to the (now fixed) FX2 power bug on the FPGA that
surfaced with the Ubuntu Feisty Fawn kernel?

[stevie.glass]

On Wed, May 02, 2007 at 06:35:53PM -0500, Brett L. Trotter wrote:

When I run usrp_fft.py things are fine for a few moments but inevitably

You may want to try a different USB cable. It might be flaky.

Eric

Could this be related to the (now fixed) FX2 power bug on the FPGA that
surfaced with the Ubuntu Feisty Fawn kernel?

Could be, but I don’t think so.

Eric

[stevie.glass]

Hi

fusb: (rd status -71) Protocol error

So, I removed the other USB devices, removed the cable and vacuumed the
connectors. (This PC is a fluff magnet). Reattached the cable to a
neighbouring connector (by accident but not changing it now!) and lo and
behold no more protocol errors.

Thanks to everyone for your help and suggestions.

Steve

[stevie.glass]

Eric B. wrote:

Eric
I’m totally not sure if this is the same error or not, but I’ve gotten
an error
-71 with the USRP before… but only when first plugging it in and then
it
typically would not work. Is there anything else on your USB bus? I
had a
webcam running on my bus also, that when I turned off and removed the
error went
away. I don’t know if it was a synchronization or timing issue or what.
Not
sure if this is totally related or relevant, I just remember seeing -71

• George