9-1
9.1 FAULT FINDING
In case of semiconductor circuits, it is deemed that there are few cases in which the used
semiconductor devices have inferior quality or performance deterioration except due to
insufficient design or inspection or by other external and artificial causes. In general, the
relatively many causes are disconnection in a high-value resistor due to moisture, a defective
variable resistor and poor contact of a switch or relay.
Some troubles are caused by defective parts, imperfect adjustment (such as tuning adjustment)
or insufficient service (such as poor cable contact). It will also be effective to check and
readjust these points.
9.1.1 List of Alarms and other Indications
If any of the following alarm occurs, the system displays the alarm message in red in order to
attract the attention of operator. Other messages are displayed with the suitable color which is
yellow or blue depending on the level of message importance.
Alarm
:Red :Collision-related Alarm
:Navigation Alarm
:System Alarm
Warning :Yellow :System Warning
Information
:Blue :Operation Information
Alarm message is displayed in the lower right of the display. For operation details refer to
page2-29 Alarm.
Table 9-1 Critical Alarm
Message Class Description
ALR
No.
CPA/TCPA Alarm There is a dangerous target. 301
ALR No : Unique alarm number in ALR sentence and ACK sentence.