[USRP-users] N210 Stops Transmitting

Liwei xieliwei+usrp at gmail.com
Mon Oct 20 10:24:45 EDT 2014

Hi all,
    Sigh, should have known I'm not lucky enough to have this go away.
Couldn't get transmit to work without stopping when I checked in
today. Did the same things I did yesterday to try to replicate the
result, but no go.
    So here's the information requested.
    Unfortunately, I can't get tx_waveforms running long enough to see
it do anything on top, even with delay set to 0.5s. id hovers above
95% and us hovers below 4% or so:
        %Cpu(s):  1.0 us,  0.5 sy,  0.0 ni, 98.5 id,  0.0 wa,  0.0 hi,
 0.0 si,  0.0 st
    tx_waveforms seems to be doing nothing once transmission stops:
        PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM
        4554 xieliwei -51   0  173568  11876  10756 S   0.0  0.1
0:00.09 tx_waveforms
    Here's how running tx_waveforms look like, the "S" appears
instantly and nothing gets transmitted:
$ /usr/lib/uhd/examples/tx_waveforms --rate 200000 --freq 144300000
--gain 20 --wave-type CONST
linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.008.000-6-gbde8e9a3

Creating the usrp device with: ...
-- Opening a USRP2/N-Series device...
-- Current recv frame size: 1472 bytes
-- Current send frame size: 1472 bytes
Using Device: Single USRP:
  Device: USRP2 / N-Series Device
  Mboard 0: N210r4
  RX Channel: 0
    RX DSP: 0
    RX Dboard: A
    RX Subdev: WBXv3 RX+GDB
  TX Channel: 0
    TX DSP: 0
    TX Dboard: A
    TX Subdev: WBXv3 TX+GDB

Setting TX Rate: 0.200000 Msps...
Actual TX Rate: 0.200000 Msps...

Setting TX Freq: 144.300000 MHz...
-- Tune Request: 144.300000 MHz
--   The RF LO does not support the requested frequency:
--     Requested LO Frequency: 144.300000 MHz
--     RF LO Result: 144.299451 MHz
--   Attempted to use the DSP to reach the requested frequency:
--     Desired DSP Frequency: 0.000549 MHz
--     DSP Result: 0.000549 MHz
--   Successfully tuned to 144.300000 MHz
Actual TX Freq: 144.300000 MHz...

Setting TX Gain: 20.000000 dB...
Actual TX Gain: 20.000000 dB...

Setting device timestamp to 0...
Checking TX: LO: locked ...
Press Ctrl + C to stop streaming...

    As for NetworkManager being the cause, I have it set to manual
configuration, no go. It won't explain how receive works fine while
transmit stops too, and the problem is the same on OS X on an entirely
different laptop. Nothing in the system logs too.

    I'm starting to suspect that the N210 I have is faulty.


On 20 October 2014 02:17, Liwei <xieliwei+usrp at gmail.com> wrote:
> Hi all,
>     My mind is officially blown now. Everything suddenly works.
>     After returning the MacBook to my friend, I started collecting the
> data Marcus asked for. The first thing I did was to load new firmware
> with usrp_n2xx_simple_net_burner (since the UHD version on my laptop
> is newer than the one from macports on the MBP). Next I tried to run
> the tx_waveforms test as suggested. I was expecting the same result
> since tx_waveforms should behave similar to uhd_siggen. To my
> surprise, it actually worked without issue.
>     So I went back to uhd_siggen thinking maybe the problem lies with
> gnuradio. Again, I was surprised when it actually worked fine. Then I
> tried the test flow graph, then the flow graph I was working on, on
> fast ethernet, on the USB3 gigabit ethernet adapter, and even Wi-Fi.
> Now I have uhd_siggen running at 2.5Msps over Wi-Fi for the past 15
> minutes without issue.
>     3 weeks recompiling different UHD/GNURadio versions, power
> cycling, firmware updating, swapping network devices around, network
> capturing, and things suddenly start working without clear
> explanation.
>     So there are a few things that could have solved the problem:
>         1. Switching to the older firmware/UHD/gnuradio version from the MBP
>         2. Switching back to the new firmware/UHD/gnuradio version
> from my laptop
>         3. Running tx_waveforms (does it do anything especially
> different from uhd_siggen?)
>         4. Sentience, I did hint in my previous email of replacing
> this USRP unit with the spare ;)
>     To be sure, I just power cycled the N210 and rebooted my laptop.
> Still works. Hopefully this holds up and what I've provided so far is
> of use in figuring out what exactly was happening.
> Thanks
> Liwei
> On 20 October 2014 00:55, Liwei <xieliwei+usrp at gmail.com> wrote:
>> Whoops, attached the generated python instead of the flow graph. See attached.
>> On 20 October 2014 00:50, Liwei <xieliwei+usrp at gmail.com> wrote:
>>> Hello Marcus, Marcus,
>>>     Thanks for the reply. I'll get back to what the two of you have
>>> asked me to check in the next email. At the moment, I managed to get
>>> myself a mid-2010 MacBook Pro (running OS 10.10) from a friend. It
>>> runs on a 2.66GHz i7-620M (Arrandale) processor with a BCM5701 gigabit
>>> ethernet controller.
>> --Snip--

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