Re: [Discuss-gnuradio] Synchronizing 3 USRP-N200

[Zooz Engineer]

Dear Ian and All,

Although I tried what you have said, the phase is random and different every time I run the flow graph. I deeply suspect that synchronization is actually done on the boards.
I use a GPS receiver for synchronization and yesterday I noticed that the shape of the PPS signal is as the one in the attached image. I am afraid that the ripple and the overshoot can imitate the behavior of the PPS in much smaller period than one sec. Do you believe so? Can I use a usual function generator for the PPS instead of the GPS receiver? In other words, should the ref/pps signal be sync?
Best regards,
Zo

---

Subject: Re: [Discuss-gnuradio] Synchronizing 3 USRP-N200
From: address@hidden
Date: Wed, 3 Apr 2013 11:59:20 -0700
CC: address@hidden
To: address@hidden

Zo,

Have you tried swapping cables between USRP's? both REF/PPS and signal (one at a time) to see if the apparent phase differences follow particular cables/signal paths?

On Apr 3, 2013, at 2:32 AM, Zooz Engineer <address@hidden> wrote:

Hi Marcus, 

Thanks for replying. I did the following test after your comments: 

1- to rule out the scope sink problem, I used a file sink and plotted the output using octave: Same results observed. 
2- I took the outputs of the splitters to the oscilloscope and there are aligned. 

Are there other ways to test Ref/PPS other than the one I mentioned in my original mesage? 

Best/ 

Zo

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Untitled0.png
Description: PNG image