Safran SecureSync 2400 User Manual page 197

configured to be either the rising or falling edge of the 1PPS signal (by default, the
rising edge is the on-time point).
There is a fixed phase relationship between the 1PPS and the 10 MHz outputs, as
described below:
Like other types of SecureSync's signal outputs, a 1PPS output can be configured
in several ways:
CHAPTER •
2 SecureSync 2400 User Manual Rev. 5.2
SecureSync equipped with
oscillator: With oscillator disciplining active (one or more 1PPS references
available and valid) and after the on-time point has been initially slewed
into alignment with the selected reference, there will always be exactly
10 million counts of the oscillator between each 1PPS output, even while in
the Holdover mode (= input references are currently unavailable) and even
after input references have become available again.
SecureSync equipped with
ciplining active (one or more 1PPS references available and valid), after the
on-time point has been slewed into alignment with the selected reference,
with the exception of 1PPS input reference changes occurring, there will
always be exactly 10 million oscillator counts between each PPS output
pulse.
With the Rubidium oscillator installed, when a 1PPS input reference change
occurs (such as switching from IRIG input to GNSS input, or switching from
a reference being valid to no reference being present or valid—known as
the Holdover mode), the oscillator counts between two 1PPS outputs may
momentarily not be exactly 10 million counts. Once the reference transition
has occurred, however, the counts between each PPS output pulse will
return to exactly 10 million counts.
Signature Control allows you to determine under which conditions an out-
put signal shall be present, i.e. what SecureSync will do about a given out-
put when an external reference is lost. See also
page 183.
The on-time point of the 1PPS signal: rising or falling edge
The pulse width
An offset can be entered to account for cable delays or other latencies.
TCXO/OCXO/Low-Phase-Noise Rubidium
Rubidium (Rb) oscillator: With oscillator dis-
"Signature Control" on
2.20 Configuring Outputs
181