Re: [Discuss-gnuradio] UHD transmission timing control is quite tricky yet.

[Josh Blum]

The multi usrp wrapper has a method built in to synchronize a collection
of devices when the PPS edge event is unknown to the computer. You may
want to use the multi_usrp, and in any case, see the comments on
synchronization here:
http://www.ettus.com/uhd_docs/doxygen/html/classuhd_1_1usrp_1_1multi__usrp.html#a413014bf3aea4a8ea2d268b4a3b390e9

On 01/19/2011 09:29 PM, Sangho Oh wrote:
> I am trying to achieve two synchronized transmissions from two USRP2s.
> Both USRPs are connected to each host PC and feed with 5PPS clocks, without
> 10Mhz reference clock.
> But I cannot make it happen yet.
> 

no common reference means clock drift

> 
> However, the two transmissions are not synchronized well. There is a
> significant timing offset between the two transmissions, which
> is hundreds of milliseconds.
> 

perhaps a multiple of 200 ms, which is the period of your pulses.

-josh