Synchronization between two E100 devices

GNU Radio
1

Hi everyone,

I’m trying to synchronize two E100 devices, both connecting to the
ethernet. According to the Synchronization Application Notes of UHD,
there are a couple of methods to do it. But the problem is that I don’t
have access to either an external GPSDO or a reference clock signal.

I tried to access both devices by providing the IP address of
uhd_usrp_source/sink, then set the time of them using the set_time_now()
method. But it turned out that another m’board is not accessible to the
host device.

So I was wondering, under this circumstances, is there a way to
synchronize the device time of two E100s?

Thanks in advance,

Terry

2

On Mon, Sep 26, 2011 at 8:52 AM, ziyang [email protected] wrote:

device.

So I was wondering, under this circumstances, is there a way to synchronize
the device time of two E100s?

If you need them to be truly synchronized, then the only way to do it
is by distributing an accurate PPS and 10MHz reference to them.
Issuing set_time_now() “simultaneously” to two devices will get you
within some microseconds, but not synchronize them at the sample
level.

–n

3

Hi Nick,

Thanks for your reply. In my application, a microsecond-order accuracy
will be enough for the synchronization right now. But I didn’t manage to
issue set_time_now() to the other usrp because it seems only the usrp of
the host device is accessible. So I was wondering if there is a way to
access another e100 from the host device?

Thanks,

Terry