Symmetricom XLi IEEE 1588 User Manual
Page 79
XLi IEEE 1588 Clock
71
997-01510-03, Rev. C, 12/12/2006
2
5
1
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
Alarms - General Information
With Alarm Disabled, an F73 indicator does not trigger and alarm when it enters an Unlocked or Fault
state.
With Alarm Enabled, an F73 indicator triggers an alarm when it enters an Unlocked or Fault state, and
the following events take place:
•
The Alarm Status LED changes color from green to amber or red (
)
•
The ALARM output on the rear panel changes from low Z to high Z (impedance).
•
If configured, SNMP sends a trap out over the network port. (
The following items may delay an unlocked or fault state from triggering an alarm immediately:
•
Timeout and Timeout Delay postpone Time Error alarms for a user-configured interval.
“Timeout and Timeout Delay” on page 71.
•
Power-on Alarm Suppress prevents alarms from being triggered for a user-configured interval
after the XLi boots and starts.
See “Power On Alarm Suppress” on page 72.
Time Error and Time Threshold
Time Threshold sets the threshold in ns above which Time Error triggers an alarm. When the oscillator’s
predicted worst-case time error (
) exceeds Time Threshold, Time Error
enters a fault state.
Note:
When Time Threshold is set to zero, it defaults to an appropriate value for the type of refer-
ence source. For example, when Time Threshold is set to “0”, the XLi applies 150 ns as the
value while the reference locked to a GPS reference.
LED Blink
When LED Blink is enabled, the Alarm Status LED on the front panel blinks when it is green or yellow.
The LED does not blink when it is red, even if LED Blink is enabled. Some users disable LED Blink to
ensure that the LED’s color (state) is displayed without interruption.
Timeout and Timeout Delay
Timeout and Timeout Delay allow you to add the dimension of time to the Time Error indicator. With
Timeout disabled, a Time Error fault triggers an alarm immediately. With Timeout is enabled, a Time
Error fault starts counting down the number of seconds specified by Timeout Delay. When the Timeout
Delay countdown finishes, the Time Error fault triggers an alarm. (Note: the Alarm Status LED on the
front panel turns amber while the Timeout Delay is counting down). If the Time Error fault returns to an
OK state during the Timeout Delay countdown, the countdown clears. A new Time Error fault starts the
Timeout Delay countdown from the beginning. In other words, Timeout Delay countdown does not keep
track of the cumulative duration of multiple Time Error faults.