diff options
author | Martin Braun <martin.braun@ettus.com> | 2016-08-18 12:48:03 -0700 |
---|---|---|
committer | Martin Braun <martin.braun@ettus.com> | 2016-08-18 12:48:03 -0700 |
commit | 99825c81d3e766177b0bdc57e5315a8c75a7dc32 (patch) | |
tree | 30c4299aa47747186a95a0de3aecaf6489a768a7 /host/docs/sync.dox | |
parent | 41d48c939f0bed80ba4af4a92cf8483cd42ce6a8 (diff) | |
download | uhd-99825c81d3e766177b0bdc57e5315a8c75a7dc32.tar.gz uhd-99825c81d3e766177b0bdc57e5315a8c75a7dc32.tar.bz2 uhd-99825c81d3e766177b0bdc57e5315a8c75a7dc32.zip |
docs: Minor updates to device synchronization manual page
Diffstat (limited to 'host/docs/sync.dox')
-rw-r--r-- | host/docs/sync.dox | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/host/docs/sync.dox b/host/docs/sync.dox index 5a0870bea..8c609f407 100644 --- a/host/docs/sync.dox +++ b/host/docs/sync.dox @@ -64,10 +64,10 @@ synchronize multiple pairs of devices. \section sync_time Synchronizing the Device Time The purpose of the PPS signal is to synchronously latch a time into the -device. You can use the `set_time_next_pps(...)` function to either +device. You can use the uhd::multi_usrp::set_time_next_pps() function to either initialize the sample time to 0 or an absolute time, such as GPS time or UTC time. For the purposes of synchronizing devices, it doesn't matter -what time you initialize to when using `set_time_next_pps(...)`. +what time you initialize to when using uhd::multi_usrp::set_time_next_pps(). \subsection sync_time_reg Method 1 - poll the USRP time registers @@ -100,15 +100,13 @@ PPS edge, and the user can also parse this string to determine GPS time: usrp->set_time_next_pps(uhd::time_spec_t(gps_time+1)); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -\subsection sync_time_internalgps Method 3 - internal GPSDO +\subsection sync_time_mimocable Method 3 - MIMO cable -USRP devices with internal GPSDOs properly configured will automatically -configure themselves to set the VITA time to current UTC time. See \ref page_gpsdo -for more details. +Note: This only applies to USRP2 and N200/N210. This method does *not* +require a separate PPS input to the devices, but it is limited to +a total of 2 USRPs. -\subsection sync_time_mimocable Method 4 - MIMO cable - -A USRP device can synchronize its time to another USRP device via the +A USRP2 device can synchronize its time to another USRP device via the MIMO cable. Unlike the other methods, this does not use a real "pulse per second". Rather, the USRP device sends an encoded time message over the MIMO cable. The slave device will automatically synchronize to the |