Specifications

4-19
Operating Features and Specifications
Measurements
• Bit Count
• Error Count
• Delta Error Count
• Error ratio
• Delta Error Ratio
• 0 - >1 Error Count
• 0->1ErrorRatio
• 1 - >0 Error Count
• 1->0ErrorRatio
• Errored Intervals - intervals seconds, deciseconds, centiseconds, milliseconds
• Error-free Intervals - intervals seconds, deciseconds, centiseconds, milliseconds
• Sync Loss Seconds
• Power Loss Seconds
• G.821 Error Analysis
The Bit Count result is provided in particular for use whenever the detector's Gating Input
is being used to enable the bit error counters both in Normal and Burst Gating modes.
Whenever the Gating Input is switching the measurement period is not continuous and
hence the number of measured bits will no longer be equal to the Gating Elapsed
multiplied by the Err Det Clock Freq. The ratio:
Bit Count
Gating Elapsed * Err Det Clock Freq
allows the user to confirm the proportion of the measurement gating period for which the
Gating Input enabled the clock and bit error counters.
Error Analysis
The Error Analysis is based on CCITT Rec G.821 and is derived from the bit error results.
• % Unavailability
• % Availability
• % Errored Seconds
• % Severely Errored Seconds
• Degraded Minutes
Power-loss Seconds
This is displayed as the number of seconds the error detector is not able to make
measurements during a gating period due to ac power loss. The gating continues to the end
of the selected period following a restoration of power.