EXFO FTB-8100 Series Transport Blazer for FTB-200 - Manual (Page 259)

DSn Tabs
SONET/SDH Application 247
DS3 FEAC RX
³
Loopback: A Loopback command message has been detected in the
last second. A valid loopback command is detected only when
receiving 10 consecutive occurrences of a specific Loopback
Command immediately followed by 10 occurrences of a specific
Channel Codeword.
³
Unassigned: An unassigned message has been detected in the last
second. An Unassigned message is only detected when receiving at
least 10 consecutive occurrences of a specific unassigned codeword.
An Alarm/Status codeword is also reported since Unassigned is part
of the Alarm/Status group.
Alarm/Status Unassigned Messages
Displays the current and previously received Codeword messages.
Current: Indicates the last valid message, if any, received in the last second
of measurment.
Previous: Indicates the message, if any, that was received just before the
current measurement.
Loopback Commands
Current: Displays the valid message received in the last second of
measurement. A valid message is detected only when receiving 10
consecutive occurrences of a specific Loopback Command immediately
followed by 10 occurrences of a specific Channel Codeword. See DS3
FEAC TX on page 242 for more information.
Previous: Displays the last valid message received excluding the actual
Current message.