EXFO FTB-8500 Series for FTB-500 User Manual
Page 374
Advanced Tab
360
FTB-8500 Series and FTB-8120NGE/8130NGE
Service Disruption Time (SDT)
Unit: Select the unit for the statistics. Choices are μs, ms, s, and min.
The default setting is ms.
Note: When the measured SDT is equal or longer than the Test Period, then the
SDT equals the Test Period time.
Service Disruption: Indicates the time (in seconds) during which
there is a disruption of service due to the absence of traffic or to the
detection of defects. The H and C LEDs indicate respectively the
current (C) and history (H) SDT measurement states.
The C (Current) LED is red if there is an SDT, and lasts until the next No
Defect Time period for Defect Mode, and until the next frame for the
No Traffic Mode. For No Traffic Mode, the LED will only turn red when
the No Traffic Mode period has been reached or exceeded. The C LED
is green when there is no SDT. After an SDT with Defect Mode, the C
LED will only turn green after the No Defect Time has been met.
The H (History) LED indicates if any SDT occurred in the past (LED is
red) or not (LED is green).