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Service manual CS3000
Chapter 3: Interface board GSK-2 3-30
The circuit boards of the central unit
Document no.:
S-4-007.875/E
Prepared:
1995-03-17 Fia
Revision:
R4 2004-03-15 BM
© 2002, Consilium Marine AB
1. Voltage stabiliser
The board has a local voltage stabiliser for 5 VDC power and 12 VDC power.
The 5 VDC is supplied to all logical circuits on the board. The presence of
both powers is indicated by an LED. If one of the voltages should disappear, a
signal is activated in the back-plane.
2. Supervision
The battery voltage is fused. If the fuse is blown a signal is activated in the
back-plane. The fuse is accessible on the front panel of the board, and can be
used for disconnecting the power.
3. Address switch
The address of the first section is set with this switch. The other three sections
automatically receive the next three consecutive addresses.
4. IDA
Alarm signals, fault signals and status information are collected by two IDA-
circuits, which communicate with the central unit. The IDA-circuits also
controls the sections.
5. Control logic
Alarms and faults are latched in the GSK-2 board and at reset from the control
unit the section is turned on and off again. Common fire alarms and cable
break fault signals are also generated in the GSK-2. The alarm and fault
signals are added which gives an analogue signal, enabling the IDA to give an
auto-alarm.
6. LED indications
Fire alarm and fault indication are indicated on the front panel by one LED
each per section.
7. Fire, fault and status detection
Fire alarms and faults are detected by two comparators. The signals are filtered
before reaching the comparators. The status signal is an analogue signal that is
used to indicate the status of the section, if it is "on", "off" or has disconnected
smoke detectors.
8. Test and inhibit logic
When the disconnect smoke detector function is activated the output voltage to
the sections is lowered to 12 VDC.
9. Electrical isolation
Each section can be electrical isolated from the central unit by a double relay.
10. Barrier
Each section output is protected against transients and hf-interference.