8. DIGITAL SELECTIVE CALLING (DSC)
8.1 Introduction
Digital Selective Calling is a semiautomatic method for controlling VHF, MF and HF radio calls. It
was also designed as part of the global marine security and emergency response system
(GMDSS). It is likely that DSC will eventually replace audio calls on emergency frequencies and
will be used to send urgent and routine radio-transmitted maritime security information. This new
service will allow crafts to send/receive calls of an emergency, urgent, security, or routine nature to/
from vessels equipped with a DSC transceiver.
To avoid accidentally sending a distress call or a call sent incorrectly, contact your
vendor or local authorities for updates on DSC operating and emergency procedures.
8.2MobileMarineIdenticationService(MMSI)
Important! To send/receive DSC calls, the user must program his personal MMSI code into
the transceiver. This is a nine-digit number used by marine transceivers equipped for DSC
digital selective calling. This number is used much like a telephone number for contacting
other, specic vessels.
DSC transmissions can be done only if you have been assigned the individual MMSI
code and you entered it in your radio (otherwise the DISTRESS/DSC controls will be
disabled).
Sending a distress call without founded reason is a criminal offence. Never use this
function unless you nd yourself in a situation that merits asking for help.
8.3 Navigating the DSC menu
NEPTUNE 100 offers many DSC functions. For this reason it was created
Once inside a sub-menu, you can return at any time to the main menu by pressing the
PTT button or long pressures of MENU/SELECT button.
To return to the radio mode, conrm EXIT in every menu.
8.4 Individual call (ROUTINE TO)
The user can carry out an individual call to a specic DSC station (a vessel or a costal station).
To carry out calls, you have to enter the MMSI code manually or recall it from the preprogramed
MMSI directory.
• Keep pressed MENU/SELECT till DSC CALL is displayed;
• Conrm your selection by pushing MENU/SELECT; the display will show INDIVIDUAL. Push
MENU/SELECT again for conrmation;
Now you can choose whether inserting the MMSI code manually or recall it from the directory
previously set
• Scroll with the UP/DOWN keys the 9 digits composing the code;
• Conrm by pushing MENU/SELECT;
• With the UP/DOWN keys select one of the 23 channels available (simplex) and conrm your
selection with MENU/SELECT.
