On 03/01/2016 04:57 AM, Nigel Steed wrote:
Hi All,
Has anyone managed to use/modify the UHD Source Block to phase
synchronise multiple N210/SBX ?
From what I have read I must perform the following
(1)Configure to use external references (10MHz and 1PPS) using the
options in the UHD Source Block
(2)Use integer N mode for the PLL
(3)Re-tune the frequency of the PLL’s on multiple N210/SBX at the same
using a time command
(4)Align the CORDIC’s at initialisation and after a re-tune from (2)
above by stopping and starting a stream disciplined to a time command
which issues a reset to the CORDIC’s at the same time
Thanks,
Nigel
The only thing really missing in gr-uhd is the ability to do timed
commands. You can force integer-N mode by constructing your own
tune_request that includes the integer-N option. You'd use a feature
from the latest Gnu Radio to help you with this, because it involves
getting into the internal structure of a tune_request blob. So, use
the "Python module" block, and in that Python do something like:
def integer_N_tune_me(freq):
r = uhd.tune_request(freq)
r.args = {"mode_n" : "integer"}
return r
Then, in your UHD source/sink block, instead of using your target
frequency directly, use:
your_module_name.integer_N_tune_me(desired_freq)
Martin could probably comment on the feasibility of adding timed
commands to gr-uhd.
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
