On 07/16/2012 10:17 AM, Alexander Olihovik wrote: > Hello all, > I have general questions on streams: > > 1. When precisely does a stream start? When a source is connected to its > sink? When you call .run() on a top-block? >
The UHD Source block has a set_stream_time() which you can call before starting the flow graph. This will precisely control when samples start flowing. > 2. When adding stream tags to a stream, does the stream itself get altered? No. The tags are basically in an external queue and and tied to the absolute sample count of the stream. > If I were to output the stream to a binary file, would the file look the > same with and without stream tags? > Yes. There isnt a facility to write the tags yet. But I have heard of a such a utility in the works. > 3. If I have multiple USRPs receiving data at the same frequency and > sampling rate, all outputting their streams to separate binary files, will > sample n on binary file 0 be taken at the same time as sample n on binary > files 1, 2 ... up to the number of USRPs, assuming all USRPs have been > synchronized with the same clock and PPS signal? > > Yes, 1) If you have multiple source blocks and set the stream time to be the same. Or, 2) you have a multi channel source block, this will just work as all channels are automatically aligned -josh _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
