[Discuss-gnuradio] USRP2 slave PPS signal over the MIMO cable

[David Scaperoth]

I would like to run two USRP2's as master and slave, and I would like to only use a 1PPS on the master (each USRP2 would be controlled by two separate processes).  When I run the test_pps_input on the slave, the program fails.  However, the master is able to find the PPS just fine.  I've tried a combination of running the master, then running the slave/running the master at the same time as the slave/running the slave then the master/etc with no luck.  I think short of probing the pins on the MIMO cable or perusing the FPGA code (which I believe is not available to the public), I'm pretty much out of ideas. 

 

One thought I had was that adjusting from clock_config_t::internal to external might help, but on further review of the code, the PPS does not appear to be affected by this.  I have seen some posts about this, but none after January 20th (the most recent UHD announcement about MIMO upgrades).  Any

 

Thanks in advance,

 

David