NSR Marine NVR-3000, Operation And Installation Manual

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NVR-3000 OPERATION MANUAL & INSTALLATION MANUAL
NVR-3000 OM.E 20210412-02
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4. DSC OPERATION
4.1 DSC Description
DSC (Digital Selective Calling) is an important mean for emergency calls at sea. It’s a part of GMDSS (Global
Maritime Distress and Safety System) set by IMO (International Marine Organization).
DSC should be primarily used for distress, urgent and safety call and response to such calls, in addition, it can be
used for general service between ship to ship and ship to shore station and if automatic service is provided for by
coastal stations for direct access to shore-based public telephone network.
4.1.1 DSC Message
Normally, the contents of a DSC call include Calling category, Station ID (MMSI), Priority, Communication mode,
Communication channel (frequency), Position, DSC channel (frequency), End code.

Calling category
DSC calls are roughly divided in two groups: distress calls and general (urgency, safety and routine) calls. Below
are the types of DSC calls.
Call category Call
DISTRESS
DISTRESS ALERT, DISTRESS RELAY ALL, DISTRESS RELAY INDIVIDUAL,
DISTRESS RELAY INDIVIDUAL ACK, DISTRESS ACK
，
DISTRESS CANCEL ACK
GENERAL
MEDICAL MSG*, NEUTRAL MSG*, INDIVIDUAL MSG, TEST MSG, GROUP MSG,
ALL SHIPS MSG, POSITION MSG, POLLING MSG
*SPECIAL MSG: To send these messages, set [SPECIAL DSC] to [ON] .

Station ID (MMSI)
Ship station ID: MIDxxxxxx
Coast station ID: 00MIDxxxx
Group ID: 0MIDxxxxx
Above, MID (Maritime Identification Digits): Country code, x…x: Digital number.

Priority
Distress : In grave and imminent danger and request immediate assistance.