Symmetricom Z3801A, User Manual

Page: 39 / 98

Chapter 2 Features and Functions
Indicators
User Guide 2-9
Indicators
Power Indicator
This indicator lights when the input power is supplied to the Receiver.
Enabled/Active Indicator
These user definable indicators light when turned on through the
RS-422 serial interface port.
Alarm Indicator
The Receiver lights this indicator to indicate it has detected an internal
condition that requires attention.
Refer to Table 4-2 in Chapter 4, “Command Listing and Status
Information” of this guide for information on Alarm capability.
GPS Lock Indicator
This indicator lights when the Receiver is tracking satellites and
phase-locked its internal reference to the reference time derived from
satellite data. This indicator will go off whenever the above condition is
not met, which would typically occur when satellite tracking is lost or
while the Receiver is powering up.
The principal Receiver setting that can affect this indication is manual
selection of reference oscillator holdover operation.
Holdover Indicator
The Receiver lights this indicator to show that GPS lock has been lost
and the Receiver is in holdover mode. It only lights it the Receiver has
been locked once; it will never light until the Receiver has been locked
once. While in holdover, the internal reference oscillator will be
adjusted by SmartClock™ technology .
NOTE If the Holdover indicator lights before the Receiver has been locked
24 hours, then the Receiver has not had sufficient time to learn the
characteristics of the internal reference oscillator. In this case, the
specification for Timing Accuracy during holdover may not be met.
This specification applies only after the Receiver has had sufficient
stable operation time.
Refer to the subsection titled “Holdover Description” on page 2-11 in
this chapter for more information.