[USRP-users] USRP X310 motherboard issues

T reffahcs at gmail.com
Wed Dec 10 18:33:26 EST 2014


Matt - that makes sense, the glitches are apparent on the scope attached to subdev B. No worries, this is really the first weekend I've tried to work on the X310 since I got it, so I was concerned there may have been a hardware issue with it. Do you know if the UHD 3.7.2 drivers have the same glitch? I was thinking about installing them tonight.

-Tim 

Sent from my iPad

> On Dec 10, 2014, at 14:37, Matt Ettus <matt at ettus.com> wrote:
> 
> 
> Tim,
> 
> This is actually caused by a timing problem that crept into the FPGA builds because we had an unconstrained path.  What you are seeing is signals passing between clock domains and sometimes a few bits don't make it in time so you get a glitch.  We noticed it a few days ago, and have fixed it.  We are building new images in all the variations, and the new builds will be available tomorrow.  Sorry for the inconvenience.
> 
> Thanks,
> Matt
> 
> 
>> On Wed, Dec 10, 2014 at 10:02 AM, Timothy Schaffer via USRP-users <usrp-users at lists.ettus.com> wrote:
>> I received an X310 from NI last week along with 2 x WBX-120 boards and I've noticed a difference in signal quality between the A and B subdevs of the motherboard. Overall, It seems the signals receive from the B side are generally distorted and prone to harmonics. I naturally assumed this was an issue with the WBX boards, so I swapped them and noticed the same issues. Next I swapped the cables connected to the bulkhead and still the same issue.
>> 
>> I''m currently using UHD 3.008.000-52, but have not tried other versions. I've reloaded the FPGA firmware, ran all 3 cal routines on both subdevs. I'm not sure what else to try? I'v eattached a couple of screen shots of some of the tests I performed with an HP E4432B. The tests were done back to back using the same cable from the siggen to the USRP.
>> 
>> You can see in these two screen shots, the actual distortion to the waveform in the scope.
>> <multi_tone_B.png>.<multi-tone_A.png>
>> 
>> Here is a DQPSK(24.3ksps) test signal at 303 MHz 
>> 
>> <QPSK_A.png><QPSK_B.png>
>> 
>> Any ideas on what could be wrong, or does it need to go back to NI for repair/replace?
>> 
>> -Tim
>> 
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>> USRP-users at lists.ettus.com
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>> 
> 
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