Troubleshooting With Alarm Messages - mcmurdo SmartFind M6 AIS CLASS A Installation Manual

5.1

Troubleshooting with alarm messages

The M6 is monitoring itself constantly for failures or other important parameters with
the built-in integrity test (BIIT). In case an abnormal operation is detected in one or
more of the following conditions, an alert will be triggered and displayed on the
screen, and the transponder will react as described in the following table.
AIS: Tx malfunction
The M6 has a built-in lock detector (high active) to
monitor the local oscillator (PLL circuit) of the
transmitter. If the operation of PLL circuit becomes
abnormal, a logic low (Tx malfunction) will be sent from
the lock detector to notify the system. At the same time,
system will output an BIIT ID 001 alert at the related PI
port.
AIS: Antenna VSWR exceeds limit
The M6 has a built-in RF output power detector to
monitor the VSWR (Voltage Standing Wave Ratio) of the
VHF antenna port. If the antenna VSWR exceeds a given
limit, an alarm will be generated. If the VSWR goes
below the defined threshold, the alarm is cleared.
AIS: Rx channel 1 malfunction
The M6 has 3 built-in lock detectors (high active) to
monitor each local oscillator (PLL circuit) of receiver
channel 1, channel 2, and channel 70 respectively. If the
operation of PLL circuit becomes abnormal, a logic low
level will be sent from the lock detector to notify the
system. At the same time, the system will output BIIT ID
003, BIIT ID 004 or BIIT ID 005 alert to indicate the CH1
or CH2 or CH70 RX malfunction respectively.
AIS: Rx channel 2 malfunction
AIS: Rx channel 70 malfunction
AIS: general failure
AIS: UTC sync invalid
Description text
31
BIIT Reaction of the
ID system
(transponder)
001 Stop
transmission
002 Continue
operation
003 Stop
transmission on
affected
channel
004 Stop
transmission on
affected
channel
005 Continue
operation
006 Stop
transmission
007 Continue