Re: [Discuss-gnuradio] what is meant by "LLLLLLLLLLLLL...."?

[Josh Blum]

On 07/17/2012 04:20 PM, Zing Yu wrote:
> Hi Josh,
> 
> The "late" packet gets sent anyway. Right? At least I have verified


Late packets get dropped. Think of this as a catch-up mechanism.
Otherwise, all subsequent packets would also be late.

The late packet error follows the same policy as the underflow error:
http://files.ettus.com/uhd_docs/doxygen/html/structuhd_1_1stream__args__t.html#a4463f2eec2cc7ee70f84baacbb26e1ef

> this at the receive side. Further, I hope that one L is printed for
> each "late" burst (i.e., no. of L's equals no. of late "bursts").

Yup. That means everything transmitted 100%

> Correct? Finally, how can one print the metadata to find which of the
> bursts were late, assuming that there is a tag containing the burst
> number?
> 

There is time stamp on the async message.

You can retrieve this in the gnuradio environment via async message
block. Here is one implementation using the gr_message_queues:
http://gnuradio.org/cgit/gnuradio.git/tree/gr-uhd/include/gr_uhd_amsg_source.h

And there is a version in GrExtras that creates a custom PMT tag with
the async message:
https://github.com/guruofquality/grextras/wiki#wiki-list-of-blocks-in-this-project

-josh