Re: [Discuss-gnuradio] Sensitivity of USRP to power glitches

[Don Ward]

Marcus Leech wrote:

> Something I've noticed over the years with the USRP is that it seems
> unusually sensitive to power glitches, even tiny ones. Maybe
>  ground noise?
>
> For example, removing an RF connector while the USRP is powered up can
> sometimes cause it to go into "Protocol Error -71" in and
>  endless loop, and other things that might introduce small amounts of
> ground noise.
>
> This morning, my wife started the vacuum cleaner outside my office.  The
> USRP had been running entirely fine for 24 hours, and
>  then as soon as the vacuum cleaner started (causing a small AC
> glitch), the USRP crashed with "Protocol Error -71".

I used to have problems when turning on a desk lamp or the computer 
speakers.  On Windows I was getting usb_reap_async errors.

> Is this an USRP thing, or is it that the USB is rather noise sensitive,
> and you normally don't see it because 99% of USB devices
>  are powered from the PC, rather than independently, as the USRP is.

My problem went away when I upgraded my computer.  This make me suspect that 
it is a USB problem.

-- Don W.