Re: [Discuss-gnuradio] Multiple USRP N210s: LEDs and Ethernet lights on after program termination

[Josh Blum]

On 05/29/2012 05:36 PM, Ryan Wolfarth wrote:
> Hi list,
> 
> We've setup 4 USRP N210 rev4s with a Dell PowerEdge R510 server to collect
> RF data for GPS related experiments.  The server works great and we seem to
> be able to write 20 Msps from each device simultaneously to a RAID array
> with no overflows.  However, after each collection program is terminated,
> the Ethernet and debugging LEDs (C, D, blinking E, and F) remain on.  We
> tested this with a single device with the same result.  Does anybody know
> the cause of this and if we should be worried?  We're running UHD 3.4.2
> (downloaded 2 days ago).  All N210s were updated with the firmware/image
> downloaded from the same version and compiled from source using GNU ZPU
> Tools and Xilinx ISE 13.1 respectively.  The server is running 64-bit
> Ubuntu 12.04.  Any help is appreciated!
> 

http://files.ettus.com/uhd_docs/manual/html/usrp2.html#front-panel-leds

I would only really be worried about C which means the device is still
sending samples out of the ethernet port. This can happen if the
streaming isnt properly shutoff like ctrl+c or destructors not being called.

Additionally, (if it is still streaming) the USRP isnt getting an ICMP
destination unreachable from the host when the socket on the host
closes. Its possible that due to your network setup that this packet
doesnt get generated and/or delivered.

If it is the deconstructor issue, sometimes its useful in gr python apps
to set the top block object to None to help python garbage collect it.

tb.stop()
tb = None

I would also see if things shutoff as expected when your run one of the
included examples such as rx_timed_samples

Hope that helps!
-josh