Hi Marcus,
Can I pass the desired center frequency with a PMT message?
I want to dynamically change the transmitted center frequency of UHD: USRP Sink block.
So static frequency in the block is not sufficient.
Thanks
Dor
Hi Dor,
> 1. How to change the to integer_n tuning? Should I just type "mode_n=integer" in the
> Device Address parameter of the UHD: USRP Sink block in the grc?
yes. Or, better, instead of just tuning to the target frequency, you can pass a
uhd.tune_request_t to uhd_usrp_{sink,source}.set_center_frequency, like this:
my_uhd_block.set_center_frequency(uhd.tune_request_t(
target_freq = 2.4e9,
args="mode_n=integer"))
(you can also use a uhd.tune_request_t in the RF frequency fields of the GRC block)
Note that you're probably best off using tune_request_t anyway, as it allows you to tune
your LO far away from your band of interest, given the analog bandwidth allows for that,
using `target_freq=` and `rf_freq` or `dsp_freq`.
For more information on tuning, see the UHD manual [1]
> 2. How to know for sure what the mode(integer of fractional) of the NCO is? Can I print
> its status/get it somehow?
looking at the UHD source code: the routines responsible for tuning just themselves check
for "mode_n" being set to "integer" in the device or tune request arguments.
Best regards,
Marcus
[1] https://files.ettus.com/manual/page_general.html#general_tuning