This link contains the relevant information to the structure of a flowgraph’s top block function, which is what you pasted below. https://wiki.gnuradio.org/index.php/Handling_Flowgraphs
You may find some help regarding handling burst tags in the documentation for these blocks. https://github.com/sandialabs/gr-pdu_utils You can get what your asking for with some external python code or a snippet if the precision needed isn't particularly precise. You can just put a complex multiply before the UHD sink and automate setting the value to 0 (transmitter off) or 1 (transmitter on), adding a second command to call set_gain to 0 for tx off and your desired tx output value in tandem with the complex multiply will most likely get what you want. Placing this login in a while loop that has a time.sleep(3) would work in a python snippet. You said you’re ‘implementing’ the transmission of LoRa frames. Are you familiar with this project? It’s a full implementation of the LoRa protocol. https://github.com/tapparelj/gr-lora_sdr <end transmission> > On Jun 6, 2022, at 03:14, Vamshi Sainath Gavani <rafale10...@gmail.com> wrote: > > > Hello Folks, > > Here I'm implementing the transmission of LoRa Frames and I want to be able > to stop the flowgraph(Stop Transmitting) between frames say the packet is set > to transmit every 3s so at tx_eob turn off tx and tx_sob start tx. > Below is my Flow graph code snippet can you let me know how I can turn off/on > tx between the frames? > > def main(top_block_cls=lora_TX, options=None): > tb = top_block_cls() > > def sig_handler(sig=None, frame=None): > tb.stop() > tb.wait() > sys.exit(0) > > signal.signal(signal.SIGINT, sig_handler) > signal.signal(signal.SIGTERM, sig_handler) > > tb.start() > try: > input('Press Enter to quit: ') > except EOFError: > pass > tb.stop() > tb.wait() > > if __name__ == '__main__': > main() > Thanks and Regards, > Sainath Vamshi