Hi Philipp, exactly, use a "meta variable" that it's set on every variable changes. Sending the meta variable ( dictionary) with each change could be a problem if there are a large number of parameters to be transferred; in that case it might be useful to ‘split’ the parameter set into ‘changed often’ and ‘changes sometimes’. Actually, one could also use a ‘list’ and then derive the individual variables via the list index... I used a dictionary because they seems a little more descriptive to me.
In my application there are about ten of them and I have never encountered any problems: my ‘Control Unit’ and the ‘RF head’ are connected via a VPN and physically about 40 km apart. Attached is a small demonstration flow ;-) Enjoy! Viitorio, I3VFJ fingerprint: fb5f492a54e016c632c933d3ee4b7e38203c79ca Inviato con l'email sicura [Proton Mail](https://proton.me/mail/home). lunedì 27 gennaio 2025 18:58, Philipp Niedermayer <p.niederma...@gsi.de> ha scritto: > Hi Vittorio, > > not sure I get it, according to [1], [2] and [3] linked below it is clear, > that the variable name configured as parameter is used, and the actual <name> > of the message pair is ignored. > > Are you suggesting to to put all my variables in a single "meta variable" of > dict type? I.e. something like `meta_var = {"freq": 1e6, "gain": 5}` and then > access it like `meta_var["freq"]` instead of just `freq`? That's an > interesting approach, but it would require to change all variables in the > flowgraph, and to always send all variables even if you only want to change a > single one, right? > > Best > Philipp > > [1] https://wiki.gnuradio.org/index.php/Message_Pair_to_Var > [2] https://github.com/gnuradio/gnuradio/issues/6574 > [3] > https://github.com/gnuradio/gnuradio/blob/8cbd8526b50a96188119d11bf69b2fc701edb38a/gr-blocks/python/blocks/msg_pair_to_var.py > > Am 27.1.25 um 17:33 schrieb vitt...@pm.me: > >> Good evening everybody! >> >> Regarding this: >> "...PS: I found that the "Message Pair to Var" block is not very flexible, >> since it only allows to set one specific variable...." >> >> Actually a variable can also be a dictionary: simply creates a dictionary in >> which tag/value pairs refer to other variables. >> In a mine (never finished) project I'm using this to transfer several >> settings (TX_freq, RX_freq, various gains, PTT) between a remote RF head >> (Pluto+ and amplifiers) and a local CONTROL unit, over ZMQ sockets with very >> good results >> >> I hope it can be helpful... >> >> Vittorio, I3VFJ >> >> fingerprint: fb5f492a54e016c632c933d3ee4b7e38203c79ca >> >> Inviato con l'email sicura [Proton Mail](https://proton.me/mail/home). >> >> lunedì 27 gennaio 2025 09:16, Philipp Niedermayer >> [<p.niederma...@gsi.de>](mailto:p.niederma...@gsi.de) ha scritto: >> >>> Dear Muhammad, >>> >>> you can use ZMQ blocks to send messages to your GR program. Either directly >>> to the message port of USRP sink, or use a "Message Pair to Var" block to >>> update a flowgraph variable. You can read more about these blocks here: >>> >>> - https://wiki.gnuradio.org/index.php/Understanding_ZMQ_Blocks >>> - https://wiki.gnuradio.org/index.php/Message_Pair_to_Var >>> >>> PS: I found that the "Message Pair to Var" block is not very flexible, >>> since it only allows to set one specific variable. I am currently working >>> on a similar block that allows me to change multiple variables based on the >>> message car, so that I can control my flowgraph by sending (variable_name, >>> value) message pairs. Once I got it to work, and if there is interest, I >>> could open a PR. >>> >>> Best >>> Philipp >>> >>> Am 25.1.25 um 8:08 schrieb Muhammad Anas: >>> >>>> Dear GNU Radio Community, >>>> >>>> I'm working on a project to control a USRP channel frequency from QT >>>> creater GUI application, is it possible to implement a communication >>>> between QT and GRC using xmlrpm or tcp block etc to control the GRC >>>> parameters in real-time on the same computer in window. >>>> >>>> Kindly help me to achieve this communication. >>>> >>>> Regards >>>> Muhammad Anas
dict_ZMQ.grc
Description: Binary data
dict_ZMQ.pdf
Description: Adobe PDF document
