Spectracom Corporation
8194B, 8195B, 8197B
GPS Ageless Master Oscillator Instruction Manual
1-11
1.6.11.1 Alarm Classifications
Major Alarm:
A Major alarm is asserted when detected faults compromise output
accuracy. The alarm relays reset when the fault condition is corrected. Faults and
conditions listed below actuate a Major Alarm:
•
Frequency Error Alarm:
Measured oscillator frequency error exceeds 1 x 10
-8
or whenever an AT2 Alarm is asserted. A Frequency Alarm is also asserted at
Power On.
•
GPS Tracking Timeout 2:
The AT2 time period allotted for operation without
tracking a minimum of four qualified satellites has expired. An AT2 Alarm is also
asserted during start-up.
•
GPS Tracking Timeout 3:
The AT3 time period allotted for operation without
tracking a minimum of four qualified satellites has expired. An AT3 Alarm is also
asserted during start-up.
•
CPU Fault:
The CPU is unable to communicate with the GPS receiver.
•
Test Mode:
Unit has been manually placed in Test Mode operation from RS-232
communication port.
•
Free Run:
The automatic frequency control feature has been disabled (for
factory testing only).
•
Short Gate:
Gate time is shortened for test purposes. Measurement resolution is
reduced.
Minor Alarm:
A minor alarm is asserted when failures detected do not immediately
affect output accuracy. The alarm relays reset when the fault condition is corrected.
Faults and conditions listed below actuate a Minor Alarm:
•
Output Fault:
No output is detected from one or more of the four-rear panel
Frequency Outputs. Fault could be caused by a shorted cable, reflections due to
an un-terminated cable or removed by a Major Alarm when Signature Control is
enabled.
•
Oscillator Adjust:
Warns that oscillator is operating within 10% of the minimum
or maximum control setting. The oscillator requires manual calibration and
adjustment. Refer to the service information section for details on this.
•
GPS Tracking Timeout 1:
The AT1 time period allotted for operation without
tracking a minimum of four qualified satellites has expired. An AT1 Alarm is also
asserted during start-up.
