Owner's Handbook

Chapter 5: Digital Select Calling (DSC) 37
Chapter 5: Digital Select Calling (DSC)
The Digital Selective Calling (DSC) protocol is a globally applied system
used to send and receive digital calls. DSC uses a unique Maritime Mobile
Service Identity (MMSI) number to direct DSC calls directly to your radio,
much like a telephone number.When the DSC signal is received, the radio
quickly switches over to Channel 70 and performs the corresponding
operation.
Note: An MMSI number is required to operate the DSC equipment in this ra-
dio. You can program the MMSI number yourself one time only using the
Menu Operation described in this handbook. Otherwise, your Raymarine
dealer can program or change the number for you.
When a DSC call is received, the Ray54 Base Station automatically responds
based on the type of call. When receiving a DSC call from another vessel or a
coast station, an alert sounds and DSC data appears in the LCD – such as time
of a call, the caller and the type and priority of a call.
DSC calls fall into four categories:
• INDIVIDUAL calls are made to a specific station identified by its MMSI
number. See page 39.
• GROUP calls send transmissions that are only received by radios that
share a common Group MMSI number. See page 46.
• ALL SHIPS calls send out a message to all vessels within range that you
wish to send a Safety or Urgency message but the situation is not serious
enough for a Distress Call. See page 50.
• DISTRESS calls send your vessel’s position and time information to
other ships and shore stations, along with (optionally) the nature of your
Distress situation. See page 55.
• POSITION REQUEST calls enable you to request GPS position infor-
mation from any vessel for which an MMSI number is known.
DSC calls (except Distress) are designated as:
• ROUTINE for normal calls
• SAFETY for advisory alerts
• URGENCY for assistance when life is not in immediate danger
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