Hi Tiankun, On 20.07.2014 15:50, hutiantian wrote: > Hi Marcus, > My tx_ofdm.py is gen by tx_ofdm.grc, there are a > 'packet_headergenerator_bb' module in it. This module use > 'set_tag_propagation_policy(TPP_DONT)' to handle tags by itself. Ah ok! > I didn't find any code has touch tags in this module, but when I > connect it to Tag Debug module, I can find the tags output. This is indeed strange. However, packet_headergenerator_bb is a subclass of tagged_stream_block [1].
> In my opinion, if one module use > 'set_tag_propagation_policy(TPP_DONT)', and it does not handle it, > tags will not pass down. That's generally correct, but there's the tagged stream block exception: [1], "A note on tag propagation" tells us that one most of the time would use TPP_DONT to handle all non-length tags, whilst length tags are always passed forward. Hope that helped! Greetings, Marcus [1] http://gnuradio.org/doc/doxygen/page_tagged_stream_blocks.html > > Thanks > Tiankun > > 于 2014年07月20日 21:15, Marcus Müller 写道: >> Hi Tiankun, >> >> what's your GNU Radio version [1]? Where did you find that tx_ofdm.py? >> There is no tx_ofdm.py in my GNU Radio source tree (in none of v3.7.4, >> v3.6.5 or v3.4.2). There is a tx_ofdm.grc, which can be used to generate >> a tx_ofdm.py, but that does not (and shouldn't) contain a >> "set_tag_propagation_policy" line. >> >> Greetings, >> Marcus >> >> [1] you can find out by running "gnuradio-config-info -v" >> On 20.07.2014 14:54, Tiankun Hu wrote: >>> Hi Experts, >>> I was reading tx_ofdm.py. I found this module use >>> 'set_tag_propagation_policy(TPP_DONT)' to handle tags by itself, but I >>> cann't find the code that used to handle tag in this module. >>> I knew this module will call 'packet_header_ofdm.header_formatter()' >>> and >>> 'packet_header_default.header_formatter()', but I also cann't find the >>> handle tag code in these functions. >>> Anyone can help me figure out where does this module process tags? >>> >>> Thanks >>> Tiankun >>> >>> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
