Gps Drift Event; Gps Drift Alarm - Symmetricom TimeSource 2500 Manual

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GPS Drift Event

GPS Drift Transient Event data is processed through a leaky-
bucket alarm manager, to control escalation to an event. A drift
event represents a small error in the GPS receiver output state
outside the expected performance. Occasional drift events are
normal in locations where there are antenna obstacles or sources
of multipath. The nominal time to escalate to an event condition is
2 minutes. The maximum time to retire an event is 5 minutes.
Maintenance action required: None.

GPS Drift Alarm

The GPS Drift Event data is processed through a leaky-bucket
alarm manager, to control escalation to an alarm.
Maintenance action required:
1. If a GPS Drift event escalates to an alarm, and there are no
2. The TimeSource 2500 should not normally generate a GPS
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other GPS alarms, check that the latitude, longitude, altitude,
elevation mask, and GPS fix mode information has been
entered properly, via the BTMONitor Installation screen.
drift alarm because of multipath, even with a very limited view
of the sky. However, it is possible to reduce the impact of low-
elevation multipath, by increasing the elevation mask to
exclude low-elevation satellites. Check the elevation mask in
the BTMONitor Installation screen. Increase the elevation
mask setting, and monitor the system for 24 hours, to see if
the alarm clears. If the alarm persists, and the system
performance is unacceptable, move the antenna to a window
or wall with an improved view of the sky.
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Troubleshooting
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