As mentioned, the stream-to-message-passing gr-eventstream approach is right for you.
Best regards, Marcus On 10/29/2015 01:47 PM, s.subrata...@gmail.com wrote: > Thank you Marcus. I am trying to simulate a network with 2 transmitters and > one receiver. The TX's transmit streams at random times and the RX receives > the sum of the signals from both the TX's. The adder block however doesn't > give any output when one of its input stream is empty (i.e. when both the > inputs are not available at the same time) . That's why I'm trying to create > an intermediate block for each TX that takes in an input and outputs zeros if > the input is empty. This way the adder block would always have something to > add. Thanks. > > Subrata > >> On Oct 28, 2015, at 17:36, Marcus Müller <marcus.muel...@ettus.com> wrote: >> >> Hi Subrata, >> >> while what you plan to do is possible if you build a block with a >> general_work method and a forecast. In fact, here the forecast >> implementation will probably be pretty crucial, but also be pretty >> simple -- just always require the same amount of samples from input0 as >> you're asked to produce output, and don't require anything from input1. >> >> However, I'm pretty certain GNU Radio won't schedule your block as you >> want to (in fact, I just wrote a minimal test case to verify[1]). >> >> My general recommendation would be to write a minimal block that takes a >> stream and converts it to messages, and passes those to >> gr-eventstream[2]. gr-eventstream has blocks to do exactly that: produce >> a zero-signal when there's no (message) input, produce the content of >> the message input otherwise; you could just take that output and add it >> to your input1, and be done :) >> >> Best regards, >> Marcus >> >> >> [1] https://github.com/marcusmueller/gr-demo_assymetric_input clone, and >> run ./qa_prioritizer.py in the python/ folder >> [2] http://oshearesearch.com/tag/gr-eventstream/ >>> On 28.10.2015 21:26, s.subrata...@gmail.com wrote: >>> I am trying to create a block that has two input and one output. Its like a >>> priority multiplexer; if input0 is empty then output = input1 else output = >>> input0 ( input0 always has samples) its a stream based block. >>> How do I declare the work function, because the number of samples needed >>> from each input to produce noutput_items depends on whether input0 is >>> empty. >>> Any help in the general work function is also greatly appreciated. >>> >>> Thanks >>> _______________________________________________ >>> 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
