USRP Python repeat scheduling with 1 pps synchronisation

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Hi everyone.

I am trying to run a python script that has been generated for convenience using the non-GUI GRC option. (3.9.5.0) (Python 3.10.12)

The script sends a short (~300 ms) finite sequence of samples as ranging code to a satellite and records the return to a file after the round-trip interval (~262 ms). This sequence of events is achieved using the head block as a method of accurately counting samples, which will be important in the file content analysis. The flowgraph cycle is complete in less than 1 second, with the data file appended each run.

I am looking for a quick and hopefully elegant way of synchronising the start of above flowgraph to the 1 pps input, but on a repetitive basis, say every 10 seconds. The published notes on 1pps USRP synchronisation are very instructive, however applying the necessary scheduler control means to the python _main_ is causing the difficulty here.

Many thanks and compliments of the season.

David Taylor GD4FMB