Re: [Discuss-gnuradio] Behaviour of gs-osmosdr when multiple devices in the source

[Alexandru Csete]

On Wed, Oct 23, 2013 at 9:58 PM, Marcus D. Leech <address@hidden> wrote:
> I'm trying to understand the behaviour for gr-osmosdr when you have multiple
> devices in the source -- does it start delivering samples immediately,
>   or is there a synchronization point, so that all devices start delivering
> samples more-or-less at the same time?

Hi Marcus,

I believe the behavior is different from source to source and
basically depends on whether the source block takes advantage of the
start/stop methods. For example, the Funcube Dongle Pro and Pro+
blocks are gnuradio audio source blocks that use the start and stop
methods and therefore will not start reading samples until the flow
graph is started. In other words, two funcube dongles will be more or
less synchronized, except for the clock differences. I think it is the
same for the UHD sources.

On the other hand, I have observed that if I create an rtlsdr source
block, after a few seconds it will start spitting OOOOOO out to the
terminal until I start the flow graph. This indicates that the rtlsdr
source is started as soon as it is created.

Alex