Hi, I have a question about the PPS inputs on b200 and b200mini models.
I want to synchronize time for two b200 units. I connected the PPS to a external GPS module. The Ref port was left open(Not used). Then I set the system time with set_time_next_pps command. On another b200, the configuration was the same. The problem is, after both device time has been set to PPS with the same time spec. Their system time start to drift away after a while. In other words, the PPS signal seems not regulating the system time on a second basis. BTW, I have measured the PPS timing between these gps devices and it was only 10ns off. I've read somewhere in the usrp maling list that the b200mini with only PPS input can be used to regulate internal PLL clock. Does this mean for every PPS edge it is adjusting the internal clock and make the system time stable between two units? Can we achieve the same regulation effect on b200? I already knew that using a GPSDO with b200 is the way to go for the best synchronization result. But I didn't go that way because 1.GPSDO can break my budget and 2. I only require hardware time sync on every PPS edge. I'm grateful for any suggestions. Thanks.
_______________________________________________ USRP-users mailing list [email protected] http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
