2.2 Front Panel Controls and Indicators
5
2.2.1
Annunciator LED Definitions
The four Annunciator LED’s provide a quick reference to the Model 1133A operating status. These
LED’s should give you a basic idea if the 1133A is operating correctly.
Annunciator LED
Color
Purpose
OPERATE
Green
1133A is Powered ON
TIMESET
Green
Time is Stabilized when ON
UNLOCKED
Red
1133A Not Synchronized when ON
FAULT
Red
Internal Fault when ON
Table 2.1: Annunciator LED Definitions
The Operate and Stabilized LED’s are green and the Out-of-Lock and Fault LED’s are red.
For normal operation, with the internal clock of the Model 1133A locked and accurate, both green
LED’s should be ON and both red LED’s should be OFF. The following definitions apply to these
indicators:
◦
OPERATE
. Indicates that power is being supplied to the Model 1133A.
◦
TIME SET
. When ON, indicates that the Model 1133A is locked, that the internal clock is
synchronized to the GNSS or IRIG-B signal and that the time is at maximum accuracy.
◦
OUT OF LOCK
. Illuminates when the Model 1133A has not yet synchronized, or has lost
synchronization, with the GNSS or IRIG-B signal.
◦
FAULT
. Illuminates when an internal fault occurs. Faults are listed below.
Fault Indication
Definition
Out-of-Lock
GNSS Receiver is not receiving satellite signals.
Receiver Failure
GNSS receiver is not communicating with the 1133A.
System Failure
A System Fault is active.
Table 2.2: Fault Indications and Definitions
