Jackson Labs LC_XO - Servo:slope; Servo:tempcompensation; Servo:agingcompensation; Servo:phasecorrection

© 2012 Jackson Labs Technologies, Inc. 39
LC_XO GPSDO User Manual
4.9.5 SERVo:SLOPe
The parameter determines the sign of the slope between the EFC and the frequency variation of the
OCXO. This parameter should be set to match your OCXO’s EFC frequency slope. This command
has the following format:
SERVo:SLOPe <NEG | POS >
4.9.6 SERVo:TEMPCOmpensation
This command is not supported on LC_XO, and will return undetermined values.
4.9.7 SERVo:AGINGcompensation
This parameter is a coefficient that represents the drift of the EFC needed to compensate the natural
drift in frequency of the OCXO due to aging. This coefficient is automatically computed and adjusted
over time by the Jackson Labs Technologies, Inc. firmware. This command has the following format:
SERVo:AGINGcompensation <float> [-10.0, 10.0]
4.9.8 SERVo:PHASECOrrection
This parameter sets the Integral part of the PID loop. Loop instability will result if the parameter is
set too high. Typical values are 10.0 to 30.0. This command has the following format:
SERVo:PHASECOrrection <float> [-100.0, 100.0]
4.9.9 SERVo:1PPSoffset
This command sets the LC_XO 1PPS signal’s offset to UTC in 16.7ns steps.
Using the SERV:1PPS command results in immediate phase change of the 1PPS output signal.
This command has the following format:
SERVo:1PPSoffset <int> ns
4.9.10 SERVo:TRACe
This command sets the period in seconds for the debug trace. Debug trace data can be used with
Ulrich Bangert’s “Plotter” utility to show UTC tracking versus time etc.
This command has the following format:
SERVo:TRACe <int > [0,255]
An example output is described here:
08-07-31 373815 60685 -32.08 -2.22E-11 14 10 6 0x54
[date][1PPS Count][Fine DAC][UTC offset ns][Frequency Error Estimate][Sats Visible][Sats
Tracked][Lock State][Health Status]