# Re: GPSDO detection in B200 **URL:** \ **Category:** GNU Radio\ **Created:** [June 6, 2014, 8:52pm UTC](https://www.ruby-forum.com/t/re-gpsdo-detection-in-b200/230261 "2014-06-06T20:52:57Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\ **Post date:** [June 6, 2014, 8:52pm UTC](https://www.ruby-forum.com/t/re-gpsdo-detection-in-b200/230261/1 "2014-06-06T20:52:57Z")
Is 1PPS used if I have GPSDO installed or does the B200 assume that 10MHz is already good enough? ---
**Author:** ![rlorimor](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/96bed5/32.png) [@rlorimor](https://www.ruby-forum.com/u/rlorimor)\ **Post date:** [June 6, 2014, 9:03pm UTC](https://www.ruby-forum.com/t/re-gpsdo-detection-in-b200/230261/2 "2014-06-06T21:03:33Z")
On 06/06/2014 02:51 PM, Robert L. wrote: > Is 1PPS used if I have GPSDO installed or does the B200 assume that 10MHz is > already good enough? > > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) In all the USRPs that have 10MHz and 1PPS, the 1PPS is used only for TOD synchronization, for operations like: set\_time\_next\_pps(). There is no internal PLL that is phase-locking to 1PPS–the assumption is that the 1PPS is locked to 10MHz already, and it’s just used as a trigger for TOD (time-of-day) setting operations. – Marcus L. Principal Investigator Shirleys Bay Radio Astronomy Consortium > **[Live Draw HK Tercepat | Result HK | HK Pools | Live HK | HK Prize Hari Ini](https://www.sbrac.org)** > > Temukan live draw hk tercepat melalui halaman hk pools yang resmi dan dapatkan result hk prize melalui live hk secara langsung di situs kami.