EXFO FTB-800 Series for FTB-1 - Manual (Page 284)

Test Results
274 FTB-700G/800 Series
Alarms/Errors
PTP
Alarms

Loss Sync
RX: The Slave Clock does not receive packet timing signal messages
(Sync, Follow Up, Delay Resp) within their expected arrival time for a
duration exceeding the configured Receipt Timeout (refer to PTSF
Alarm Timeout/Threshold on page 99).

Loss Announce
RX: The Slave Clock does not receive Announce messages within their
expected arrival time for a duration exceeding the configured Receipt
Timeout (refer to PTSF Alarm Timeout/Threshold on page 99).

Unusable
RX: Either the maximum Sync IPDV value or the maximum Delay Req
IPDV value in the last second exceeds the configured IPDV Threshold
(refer to PTSF Alarm Timeout/Threshold on page 99).

QL Mismatch
RX: The received QL value does not match the Expected QL (refer to
page 99 or page 319). The QL Mismatch alarm is only reported when
at least one Announce message has already been received (Last QL
Received) and that the QL Mismatch Monitoring check box is
selected.