EPSILON CLOCK MODEL EC1S
Spectracom Corporation
EPSILON CLOCK User’s Manual
5-4
reliable time reference by programming in advance the leap second correction, ensuring it will
be applied even in the case of loss of GPS signal input.
This command does not apply to the other time references.
5.3.9 Force holdover mode
The initial functioning mode of the clock is always synchronized on the GPS reception.
However, the user may configure the clock in the holdover mode, specifically, the disciplining of
the driver frequency and if the 1 PPS is stopped.
5.3.10 Display
This command defines the format of the hour transmitted by the TOD message and displayed
on the front panel display screen if this option was chosen.
The five formats available are as follows:
•
Day / Month / Year
Hour: Minute: Second
•
Month / Day / Year
Hour: Minute: Second
•
Day of year / Year
Hour: Minute: Second
•
MJD
(Modified Julian Day)
•
MJD integer part
Hour: Minute: Second
With this command, the user defines whether the output of the hour is issued from the UTC or
GPS time reference, or from the local hour with the programmed shift.
5.3.11 Alarms limits
If the GPS input signal is lost, the clock's internal oscillator is no longer disciplined. The
frequency accuracy and the distributed synchronization start to degrade slowly according to the
ageing of the oscillator.
Using the alarms limits commands, the user may define the accuracy limits outside of which the
output signals are deemed invalid. These limit values are in the form of a time difference for the
1 PPS and in the form of a relative frequency difference for the frequency outputs.
When these limit values are reached, a fault is generated, the LED “STATUS” is fixed “off,” and
the contact relay is closed.