User's Manual
ISO 9001:2000 Cert. N°4500/1
Version 1.1 SDT_ARK6_User_Manual_ENG_vATSC Page 96 of 206
Table 21. GPS window: Holdover Management
Box
Parameter / Control
Description
Admitted Ranges / Values
General
Fine Frequency
Adjust
Internal frequency reference fine tuning setting. It is possible to
increase and decrease the frequency offset of the OCXO with
reference to the 10MHz clock by 1/21 Hz steps using the Fine
Frequency Adjust. This field is accessible only if the Frequency
Reference selector is set to Internal
Min: 0
Max: 1,048,575
General
Data to Flash
The saved DAC value during the stabilization process of the OCXO.
It represents the last saved frequency offset of the OCXO,
expressed in 1/21 Hz steps, with respect to the selected frequency
reference source.
Using External or GPS as frequency reference, the last saved Data
to Flash value will be:
retained after a software reset;
reinitialized to zero after a hardware reset (unit powered
down and powered back up).
Using Internal as frequency reference, the last saved Data to Flash
value will be overwritten with the Fine Frequency Adjust value after:
a software reset;
an hardware reset;
setting to Internal the frequency reference.
Min: 0
Max: 1,048,575
OCXO
10MHz Lock
Shows the lock status of the OCXO to the external 10MHz
reference.
Red: Not Locked
Green: Locked
OCXO
1PPS lock
Shows the lock status of the OCXO to the external 1PPS reference.
Red: Not Locked
Green: Locked