[Discuss-gnuradio] Bug with scrambler in hierarchical block

[Daniel Estévez]

Hi,

I have a hierarchical block that implements a CCSDS synchronous
(additive) scrambler/descrambler.

I have noted that the scrambler doesn't reset properly. The first bit is
wrong all the times except the first one. However, if I take all the
block inside my hierarchical block and put them on a flowgraph,
everything works fine. I'm puzzled.

See the attached files. The hierarchical block is ccsds_descrambler.grc.
The test flowgraph is test.grc. It contains both the "CCSDS descrambler"
block and a set of blocks which is precisely what is inside the "CCSDS
descrambler" block. By default, you see the output of the CCSDS
descrambler. Note that the first time the first byte is 0xff but the
remaining times it is 0x7f. However, if you disable one of the message
debug blocks and enable the other one, you'll see that the first byte is
always 0xff.

I have no clue about what could be the problem.

I'm running GNU Radio 3.7.10.1.

Regards,

Dani.

ccsds_descrambler.grc
Description: application/gnuradio-grc

test.grc
Description: application/gnuradio-grc

signature.asc
Description: OpenPGP digital signature