Hello Rob, Thanks for the response. I am not trying to get the LOs to sync in phase. I know that is not possible unless I use a common external LO. I have a method to find and cancel the phase difference of caused by the LOs. I am only trying to get the base-band Tx samples to be synced. I was wondering whether the 1-PPS signal synchronizes the 10 MHz references of all E310 in frequency or in phase.
Regarding your other question - I plan to run the software on each of the E310 independently without any host computer. Thus, if the clocks of the units can be synced I can set the transmission to start 1 minute in the future (or something similar) and I am hoping since the clocks are truly synced to get synced base-band Tx samples on different E310 units. Regards, Ofer Saferman On Fri, Dec 4, 2020 at 10:46 PM Rob Kossler <rkoss...@nd.edu> wrote: > Hi Ofer, > Here is my understanding > - The E310 can sync to a PPS signal (either external input or obtained > from GPS). From this PPS, the E310 derives the 10MHz ref signal and uses > that as ref for LO signal. So, there will be lots of phase variation > between the LOs in all of your E310 devices even though they will all be > trying to stay in sync with a 1 pulse-per-second signal. > - Regarding your time synchronization question, there are examples of > setting the E310 clock (using set_time_next_pps, I think) to match the GPS > clock. Thus, all of your E310s could have the same time. But, how do you > plan to control all of your E310s when you want the transmit to turn on? > Will you have an SSH session to each of them? > Rob > > On Fri, Dec 4, 2020 at 2:28 PM Ofer Saferman via USRP-users < > usrp-users@lists.ettus.com> wrote: > >> Hello, >> I would like to synchronize several E310 devices. >> It is my understanding that the only way to do that is by connecting a >> GPS antenna and performing disciplining to a derived 1-PPS signal. >> I have a few questions to help me better understand how to make it work: >> 1. Does GPS disciplining achieve frequency lock between devices or phase >> lock? >> 2. How to start transmitting at the exact moment on all synchronized >> devices? Can the unit clock be synchronized to GPS clock? and then just >> start the transmission with some delay from unit clock on all devices? Can >> someone share the relevant C commands to perform the time synchronization >> to GPS clock or point to a relevant code example? >> >> Thanks, >> Ofer Saferman >> >> >> -- >> This message has been scanned for viruses and >> dangerous content by *MailScanner* <http://www.mailscanner.info/>, and >> is >> believed to be clean. _______________________________________________ >> USRP-users mailing list >> USRP-users@lists.ettus.com >> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >> > -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
_______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
