Re: [Discuss-gnuradio] timed command

[Josh Blum]

On 03/04/2013 08:28 AM, Gong Zhang wrote:
> Your reply gave me much inspiration.Given the "set_command_time" would
> back-pressure all subsequent timed commands,would the data transmitting
> be suspended?

The streaming data will work independent of the backpressure when the
command queue is full.

-josh

> 
> 2013/3/4 Adeel Anwar <address@hidden>:
> 
>> > Gong,
>> >
>> > Attached is a simple freq-hopping example using timed-commands.
>> >  U may need to change "freq_list " that should match ur RF-Daughter
>> card
>> >
>> >
>> > -Adeel
>> >
>> > On Mon, Mar 4, 2013 at 5:18 PM, Gong Zhang <address@hidden> wrote:
>>  
>>> >>
>>> >>  2013/3/4 15:56, Josh Blum wrote:
>>>    
>>>> >>>
>>>> >>>
>>>> >>> On 03/03/2013 09:28 PM, Gong Zhang wrote:
>>>>      
>>>>> >>>>
>>>>> >>>> Hi,
>>>>> >>>> I wanna transmit a 1khz Sinusoidal signal for one second and
>>>>> transmit
>>>>> >>>> 2khz for another second.The code maybe something like this:
>>>>> >>>> set_command_time(&mytime)
>>>>> >>>> sig_sin_source.work(...)
>>>>> >>>> set_command_time(&mytime+1)
>>>>> >>>> sig_sin_source.work(...)
>>>>> >>>> But as I know,the first set_command_time would back-pressure all
>>>>> >>>> subsequent timed commands.This would make it impossible for
>>>>> the second
>>>>> >>>> set_command_time to reach the USRP buffer in time.
>>>>> >>>> Is it correct?And what's the suggestion?
>>>>> >>>> I appreciate any tips.
>>>>> >>>> Thank you.
>>>>> >>>>
>>>>>         
>>>> >>> For timing the transmission of samples you will want to use the
>>>> stream
>>>> >>> tagging feature of gnuradio (some examples and docs in the link):
>>>> >>>
>>>> >>>
>>>> http://code.ettus.com/redmine/ettus/projects/uhd/wiki/GNU_Radio_UHD#Using-UHD-Software-with-GNU-Radio
>>>>
>>>> >>>
>>>> >>> The timed commands thing is really for timing settings like
>>>> tuning the
>>>> >>> device, or setting gain at a specific time, its separate from the
>>>> >>> streaming interface.
>>>> >>>
>>>> >>> -josh
>>>> >>>
>>>>       
>>> >> Thank you for your valuable feedback.//If I wanna retune the
>>> device every
>>> >> second,it really has nothing to do with data stream.Maybe I should
>>> refer to
>>> >> python or UHD.Can you give me some example?
>>> >>
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> Discuss-gnuradio mailing list
>>> >> address@hidden
>>> >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>>     
>> >
>> >
>>   
> 
> 
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