© 2017 Jackson Labs Technologies, Inc. 27
Mini-JLT GNSS™ User Manual
PTIME:TINTerval?
PTIMe:LEAPsecond:ACCumulated?
3.6 SYNChronization Subsystem
This subsystem regroups the commands related to the synchronization of the Mini-JLT™ with the
GPS receiver. The list of the commands supported for this subsystem is the following:
SYNChronization:SOURce:MODE [GPS|EXTernal|AUTO]
SYNChronization:SOURce:STATE?
SYNChronization:HOLDover:DURation?
SYNChronization:HOLDover:STATe?
SYNChronization:HOLDover:INITiate
SYNChronization:HOLDover:RECovery:INITiate
SYNChronization:OUTput:1PPS:RESET [ON|OFF]
SYNChronization:TINTerval?
SYNChronization:TINTerval:THReshold [50,2000]
SYNChronization:IMMEdiate
SYNChronization:FEEstimate?
SYNChronization:LOCKed?
SYNChronization?
3.6.1 SYNChronization:HOLDover:DURation?
This query returns the duration of the present or most recent period of operation in the holdover and
holdover processes. This is the length of time the reference oscillator was not locked to GNSS
receiver 1PPS, and thus “coasting”. The time units are seconds. The first number in the response is
the holdover duration. The duration units are seconds, and the resolution is 1 second. If the Receiver
is in holdover, the response quantifies the current holdover duration. If the Receiver is not in
holdover, the response quantifies the previous holdover. The second number in the response
identifies the holdover state. A value of 0 indicates the Receiver is not in holdover; a value of 1
indicates the Receiver is in holdover.
3.6.2 SYNChronization:HOLDover:INITiate
The SYNC:HOLD:INIT and SYNC:HOLD:REC:INIT commands allow the user to manually enter
and exit the holdover state, even while GNSS signals are still being properly received. This
forced-holdover allows the unit to effectively disable GNSS locking, while still keeping track of the
state of the 1PPS output in relation to the UTC 1PPS signal as generated by the GNSS receiver. When
the unit is placed into forced-holdover with this command, the unit will indicate the time interval
difference between the 1PPS output and the GNSS receiver 1PPS by using the SYNC:TINT?
command. This allows the user to see the OCXO drift when not locked to GNSS signals for testing
purposes, or to prevent the GNSS receiver from being spoofed and affecting the OCXO frequency
To Next Page
Loading...