From 96dd54c77a50e7b1f3f618ca48f6c41bf95dcf3e Mon Sep 17 00:00:00 2001 From: Martin Braun Date: Fri, 11 Oct 2019 12:06:07 -0700 Subject: n3xx: Disable gpsdo reference source when enable_gps=0 When using enable_gps=0, the power to the LTE-Lite GPS chip is turned off, and neither the reference sources (time/clock) nor the location/time data (via gpsd) can be used. This commit disables the gpsdo options for the set_time_source, set_clock_source, and set_sync_source when enable_gps=0 is used, and adds logging to inform the user about this. This behaviour is consistent with X310, where `gpsdo` is only a valid reference if the GPSDO module is plugged in. The manual was also updated accordingly. --- host/docs/usrp_n3xx.dox | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'host/docs/usrp_n3xx.dox') diff --git a/host/docs/usrp_n3xx.dox b/host/docs/usrp_n3xx.dox index 477764e49..052f20ee9 100644 --- a/host/docs/usrp_n3xx.dox +++ b/host/docs/usrp_n3xx.dox @@ -643,7 +643,10 @@ will look like this: The N3xx series has an onboard GPSDO as well as a 25 MHz reference oscillator, which can both be used as time- and clock references. The GPSDO will function -as a reference even when there is no GPS reception. +as a reference even when there is no GPS reception. It can be powered off to +reduce power usage and interference by supplying the `enable_gps=0` option in +the configuration file (in this case, `gpsdo` cannot be used as a time or clock +reference). Note that this does not enable the synchronization of multiple devices. Using an internal reference is the default. @@ -662,6 +665,10 @@ auto usrp = uhd::usrp::multi_usrp::make( "type=n3xx,clock_source=external,time_source=external"); ``` + +Note: When disabling the GPS with `enable_gps=0` in the configuration file, or +when manually launching MPM, the `gpsdo` reference source is not available. + \subsection n3xx_synchronization_whiterabbit White Rabbit White Rabbit is an Ethernet-based synchronization procedure; it is an extension -- cgit v1.2.3