Re: [Discuss-gnuradio] UHD Announcement - July 6th 2010

[Zohair]

Dear Josh,

I have sorted out the PPS signal problem. It was the splitter that has the
problem and now I am able to output 5v signal from it. 

I tried to use an array of 2 and 3 usrp2 and it worked fine. However, the
block still doesn't work for my 4 USRP2. I see this error when I use them
all:
*****************************************
Set time with unknown pps edge:
    1) set times next pps (race condition)
    2) catch seconds rollover at pps edge
    3) set times next pps (synchronously)
 Times set to 0 successfully!      <<== note: these are printed if there's
no time deviation
 Times set to 0 successfully!
 Times set to 0 successfully!
gr_block_executor: source <gr_block uhd mimo source (1)> produced no output. 
We're marking it DONE.
***************************************

Any help, please?

Thanks again,

Zohair



Josh Blum-2 wrote:
> 
> The errors below confirm my suspicion that the sync at next pps is not 
> activated. The "Set time with unknown pps edge" routine will write time 
> zero into your devices. However, the times all read 102.xxx seconds 
> after the sync. I assume your powered them up at nearly the same time 
> (on a power switch) approximately 102 seconds prior to running the code 
> below. :-)
> 
> 1.5 volts is too low for the pps. You need 5v cmos ideally. It may be 
> possible that the load on the pps is too high. What is the pps level 
> before the splitter? I recommend an active splitter that gives you 5v 
> cmos out.
> 
> Since we have narrowed the problem down you can test this with a single 
> usrp2.To debug this, take one usrp2, attach pps and ref with no 
> splitter, modify the examples/rx_timed_example to set the clock config, 
> and set the time at next pps, sleep(1). Readback the time and see if it 
> is expected.
> 
> Thank you,
> -Josh
> 
> On 07/21/2010 04:54 AM, Zohair wrote:
>>
>> Dear Josh,
>> I have used another set of 4 USRP2's to test my program. Unlike the error
>> I
>> see when using my old set I receive this output.
>>
>> Current recv sock buff size: 50000000 bytes
>> Current send sock buff size: 50000000 bytes
>> Current recv sock buff size: 50000000 bytes
>> Current send sock buff size: 50000000 bytes
>> Current recv sock buff size: 50000000 bytes
>> Current send sock buff size: 50000000 bytes
>> Current recv sock buff size: 50000000 bytes
>> Current send sock buff size: 50000000 bytes
>> Using: Flex 2400 MIMO B RX (0x0027)
>> Using: Flex 2400 MIMO B TX (0x002b)
>> Using: Flex 2400 MIMO B RX (0x0027)
>> Using: Flex 2400 MIMO B TX (0x002b)
>> Using: Flex 2400 MIMO B RX (0x0027)
>> Using: Flex 2400 MIMO B TX (0x002b)
>> Using: Flex 2400 MIMO B RX (0x0027)
>> Using: Flex 2400 MIMO B TX (0x002b)
>> RX samples per packet: 362
>> TX samples per packet: 363
>> Recv pirate num frames: 33967
>> Set time with unknown pps edge:
>>      1) set times next pps (race condition)
>>      2) catch seconds rollover at pps edge
>>      3) set times next pps (synchronously)
>> Error: time deviation between board 1 and board 0.
>>      Board 0 time is 102.881714 seconds.
>>      Board 1 time is 102.838705 seconds.
>>
>> Error: time deviation between board 2 and board 0.
>>      Board 0 time is 102.883991 seconds.
>>      Board 2 time is 102.798313 seconds.
>>
>> Error: time deviation between board 3 and board 0.
>>      Board 0 time is 102.889212 seconds.
>>      Board 3 time is 102.832728 seconds.
>>
>>
>>>>> Done
>>
>> The differnce here is that the program keeps running and I dont receive
>> the
>> "gr_block_executor: source<gr_block uhd mimo source (6)>  produced no
>> output.  We're marking it DONE."
>>
>> Also, attached are the photos of the clock and the pps signal at the
>> output
>> of the splitters at the input of the USRPs.
>>
>> Any help with this please? I also want to know if my old set of USRPs has
>> a
>> problem.
>>
>> Best regards,
>>
>> Zohair
>>
>> Josh Blum-2 wrote:
>>>
>>> I pushed some changes to the uhd master that will check the deviation on
>>> the times between boards. This should help you to debug your setup. If
>>> you see an error message like the following, then you may have an issue
>>> with the configuration. In the following example, I disconnected the PPS
>>> on one of the boards. This is the result:
>>>
>>> Set time with unknown pps edge:
>>>       1) set times next pps (race condition)
>>>       2) catch seconds rollover at pps edge
>>>       3) set times next pps (synchronously)
>>> Error: time deviation between board 1 and board 0.
>>>       Board 0 time is 0.008782 seconds.
>>>       Board 1 time is 65.009945 seconds.
>>>
>>> gr_block_executor: source<gr_block uhd mimo source (3)>  produced no
>>> output.  We're marking it DONE.
>>>
>>> -Josh
>>>
>>> On 07/12/2010 07:14 AM, Zohair M. Abu Shaban wrote:
>>>>
>>>>
>>>> Dear Josh,
>>>>
>>>> Thanks for the info provided and the help.
>>>>
>>>> I
>>>> have 4 USRP2 boards, 2 separate function generators and 2 splitters to
>>>> supply PPS and REF clock with specs as in the FAQ page. For testing
>>>> only, I used a VRT version of the firmware that my colleague modified
>>>> to send the REF clock to the debug pins, and I was able to see that the
>>>> ref clocks are synchronized.
>>>>
>>>> I tried to work with 2 channels, 3 channels and 4 channels and wasn't
>>>> lucky enough to get something working.
>>>>
>>>> I am also interested to know if anybody has tried the MIMO block and
>>>> got
>>>> it working/not working.
>>>>
>>>> Best regards,
>>>> zohair
>>>>
>>>>
>>>>
>>>>
>>>>> Date: Fri, 9 Jul 2010 09:18:24 -0700
>>>>> From: address@hidden
>>>>> To: address@hidden
>>>>> CC: address@hidden
>>>>> Subject: Re: [Discuss-gnuradio] UHD Announcement - July 6th 2010
>>>>>
>>>>>
>>>>>> 3) set times next pps (synchronously)
>>>>>> gr_block_executor: source<gr_block uhd mimo source (1)>   produced no
>>>>>> output. We're marking it DONE.
>>>>>>
>>>>>
>>>>> This tells me that the alignment buffer is not finding a common
>>>>> timestamp among the 4 channels or one or more channels is not
>>>>> streaming
>>>>> (perhaps a timestamp/setup issue). What does your setup look like, is
>>>>> there a common pps and common reference split 4X to each usrp2? I
>>>>> forgot
>>>>> to add it to the notes but each device should have a common ref and
>>>>> pps
>>>>> attached to its front panel. Also, can you try to run with just two
>>>>> usrp2 to simplify the problem, does it work with 2 but not 3, 3 but
>>>>> not
>>>>> 4...?
>>>>>
>>>>>>
>>>>>> Sometimes I also receive these errors that disappear when I power
>>>>>> cycle
>>>>>> the USRP2's:
>>>>>>
>>>>>> Error (usrp2 recv pirate loop): bad vrt header or unsupported packet
>>>>>> type
>>>>>> Error (usrp2 recv pirate loop): assertion failed:
>>>>>> if_packet_info.has_tsi
>>>>>> and if_packet_info.has_tsf
>>>>>> in void
>>>>>> usrp2_impl::io_impl::recv_pirate_loop(boost::shared_ptr<uhd::transport::zero_copy_if>,
>>>>>> boost::shared_ptr<usrp2_mboard_impl>, size_t)
>>>>>> at /home/dave/uhd/host/lib/usrp/usrp2/io_impl.cpp:97
>>>>>>
>>>>>
>>>>> Because the previous run did not exit cleanly and stop streaming, the
>>>>> recv loop is catching the middle of a packet from the previous run.
>>>>> This
>>>>> is safe to ignore.
>>>>>
>>>>> -Josh
>>>>                                            
>>>> _________________________________________________________________
>>>> http://clk.atdmt.com/UKM/go/197222280/direct/01/
>>>> We want to hear all your funny, exciting and crazy Hotmail stories.
>>>> Tell
>>>> us now
>>>
>>> _______________________________________________
>>> Discuss-gnuradio mailing list
>>> address@hidden
>>> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>>
>>>
>> http://old.nabble.com/file/p29224741/20100720119.JPG 20100720119.JPG
>> http://old.nabble.com/file/p29224741/20100720120.jpg 20100720120.jpg
> 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
> 

-- 
View this message in context: 
http://old.nabble.com/UHD-Announcement---July-6th-2010-tp29091756p29265609.html
Sent from the GnuRadio mailing list archive at Nabble.com.