Thanks Marcus. So, it is the "select" block that is causing UHD device
to reset every time.
The reason I am using "Select" block is to avoid large file sizes, as
the interested signals can occur any time for short periods of time. So,
I have to run the program all the time, record a calibrating signal and
then wait for experiment data to occur and record this to file sinks.
Continuous recording can fill the hard disk very quickly; 1MS/s for
eight channels, something like 32MB/s or 2GB/min.
Any ideas on how can I record IQ data for discrete non-continuous
intervals of time without causing the system to re-tune.
Thanks,
Khalid.
Marcus D. Leech wrote in post #1030432:
> On 06/11/11 06:11 AM, Khalid Jamil wrote:
>> phase differences. Why?
>> The purpose is to apply and record a calibrating signal which is
>>
>>
>>
>>
> My recollection of the way the "Select" block works is that it causes
> flow-graph hierarchy reconfiguration.
> Which requires that the graph be *stopped* and *restarted* every time
> you switch. This would cause
> phase-hits in the recorded data, and I think it may also cause the UHD
> sources to shutdown and
> re-instantiated.
>
> Consider a different approach. I'm assuming that you are using a
> "select" here so that you can watch
> for correct phasing on the 'scope display before you start recording.
> Perhaps instead, record
> all the time, and insert zeros into the data stream while you're in
> the "mucking about" state, and
> when you're happy, you record the actual data. Just insert a
> multiplier into the stream in front
> of the file-sinks, and have the multiplier be either '1' or '0'
> depending on what state you're in.
>
> There are probably thinks with stream tags you could do as well, but I'm
> not that familiar with them.
>
>
> --
> Principal Investigator
> Shirleys Bay Radio Astronomy Consortium
> http://www.sbrac.org