, and I get an RSSI value on
>>>>>>>>>>> the other
>>>>>>>>>>> side of 2.5 mW, but when I run the flowgraph again, it produces an
>>>>>>>>>>> RSSI
>>>>>>>>>>> value of 9.5
>>>>
>>>>>>>>>> Thanks for the background. That helps greatly. Having said that,
>>>>>>>>>> I am unclear which commands specifically tune the radios, so I did
>>>>>>>>>> the
>>>>>>>&g
synthesizers, even when
> feed an identical reference clock, will not have the same phase offset with
> respect to one another. It's the "physics" of fractional-N PLL synthesis.
>
> SO, if you're using GRC to generate you flows, you'll have to modify the
> generated co
gt;>>>>>>>
>>>>>>>>>> Thanks for the background. That helps greatly. Having said that,
>>>>>>>>>> I am unclear which commands specifically tune the radios, so I did
>>>>>>>>>> the
>
On Tue, Jul 5, 2016 at
>>>>>>>>> 12:49 PM,
>>>>>>>>> <mle...@ripnet.com
>>>>>>>>>
(addr_string, "")),
>>>>>>>>> uhd.stream_args(
>>>>>>>>> cpu_format="fc32",
>>>>>>>>> channels=range(2),
>>>>>>>>>
> feed an identical reference clock, will not have the same phase offset with
> respect to one another. It's the "physics" of fractional-N PLL synthesis.
>
> SO, if you're using GRC to generate you flows, you'll have to modify the
> generated code, and wrap
ot;)),
>>>>>>>>> uhd.stream_args(
>>>>>>>>> cpu_format="fc32",
>>>>>>>>> channels=range(2),
>>>>>>>>> ),
>>>&g
>>>>> self.uhd_usrp_sink_0_0.set_antenna("TX/RX", 0)
>>>>>>>> self.uhd_usrp_sink_0_0.set_antenna("TX/RX", 1)
>>>>>>>> self.analog_sig_source_x_0_1 =
>>>>>>>> analog.sig_
mmand_time() around the
> place in the code where it tunes the radios.
>
> Clearly, if this depends on TIME, then all radios involved need to agree on
> the current time, to high precision, hence the related requirement for
> set_time_unknown_pps(), which uses the 1PPS signal to
gt;>>>>
>>>>>> However, when running it, this does not appear to produce a constant
>>>>>> offset either, but I'm not sure whether this is the correct code to wrap
>>>>>> around. Please keep me posted. Thanks.
>>>>>>
&g
From: mle...@ripnet.com
<mailto:mle...@ripnet.com>
Sent: Tuesday, July 5, 2016 12:35 PM
Subject: Re: [Discuss-gnuradio]
random phase offset constantly
changin
ks again.
_
From: mle...@ripnet.com
<mailto:mle...@ripnet.com>
Sent: Tuesday, July 5, 2016 12:35 PM
Subject: Re: [Discuss-gnuradio]
; complete,
>>>>>> a phase-reset pulse is sent by the FPGA. The only way for THAT to have
>>>>>> the
>>>>>> desired effect is to make sure that the phase-reset pulse happens at the
>>>>>> same instant.
>>>>>>
>&g
_
From: mle...@ripnet.com
<mailto:mle...@ripnet.com>
Sent: Tuesday, July 5, 2016 12:35 PM
Subject: Re: [Discuss-gnuradio] random phase
offset constantly changing with octoclock se
e clock. So, any two PLL synthesizers,
>>>>> even when feed an identical reference clock, will not have the same phase
>>>>> offset with respect to one another. It's the "physics" of fractional-N
>>>>> PLL
>>>>> synthesis.
>&g
re you
saying that that offset cannot be constant due to
the randomness of the LO phase offset at each run?
Thanks again.
_____
From: mle...@ripnet.com <mailto:mle...@ripnet.com>
Sent: Tuesday, July 5, 2016 12:35 PM
re you
saying that that offset cannot be constant due to
the randomness of the LO phase offset at each run?
Thanks again.
_____
From: mle...@ripnet.com <mailto:mle...@ripnet.com>
Sent: Tuesday
;>>> the generated code, and wrap set_command_time()/clear_command_time() around
>>>> the place in the code where it tunes the radios.
>>>>
>>>> Clearly, if this depends on TIME, then all radios involved need to
>>>> agree on the current time
stays constant across different runs of the
file/flowgraph. Are you saying that that offset cannot
be constant due to the randomness of the LO phase
offset at each run? Thanks again.
_____
From: mle...@ripnet.com <ma
early, if this depends on TIME, then all radios involved need to agree
>>> on the current time, to high precision, hence the related requirement for
>>> set_time_unknown_pps(), which uses the 1PPS signal to trigger loading of
>>> the time-of-day clocks on each USRP in the mul
: mle...@ripnet.com <mailto:mle...@ripnet.com>
Sent: Tuesday, July 5, 2016 12:35 PM
Subject: Re: [Discuss-gnuradio] random phase offset
constantly changing with octoclock setup
To: Pavan Yedavalli <psy2...@columbia.edu
<mailto:psy2...@columbia.edu&g
;
>>
>>
>>
>>
>>
>> On 2016-07-05 15:41, Pavan Srikrishna Yedavalli wrote:
>>
>> I am using USRP N210 with SBX daughterboards. All devices are connected
>> to the octoclock ref and octoclock PPS. It would be nice to get phase
>>
rence-with-an-offset is
sufficient if that offset stays constant across different runs of
the file/flowgraph. Are you saying that that offset cannot be
constant due to the randomness of the LO phase offset at each
run? Thanks again.
_____
From: mle...@ri
; stays constant across different runs of the file/flowgraph. Are you saying
> that that offset cannot be constant due to the randomness of the LO phase
> offset at each run? Thanks again.
>
>
> _
> From: mle...@ripnet.com
> Sent: Tuesday, July 5, 20
tant
> across different runs of the file/flowgraph. Are you saying that that offset
> cannot be constant due to the randomness of the LO phase offset at each run?
> Thanks again.
>
> _
> From: mle...@ripnet.com
> Sent: Tuesday, July 5, 2016 12:35 PM
>
that that offset
cannot be constant due to the randomness of the LO phase offset at each run?
Thanks again.
_
From: mle...@ripnet.com
Sent: Tuesday, July 5, 2016 12:35 PM
Subject: Re: [Discuss-gnuradio] random phase offset constantly changing
WHat specific hardware line-up do you have?
You have to use set_time_unknown_pps(), but also, if you want phase
alignment (as opposed to mere coherence-with-an-offset), you need to use
timed tuning commands across your systems. This will result in zero
relative phase offset between boards, if
Hi,
Despite all of my boards being connected via the Octoclock (ref and pps), I
am constantly getting different phase offsets every time I run a gnuradio
flowgraph (or python file).
I am not sure why this is happening, but I do know that I need to call one
of the functions, set_time_now() and/or
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