Humminbird VHF255SW Marine Radio User Manual


 
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14. DIGITAL SELECTIVE CALLING (DSC)
DSC (Digital Selective Calling) is a semi-automated method of establishing a radio call
that has been designated by the International Maritime Organization (IMO) as an
international standard for establishing VHF, MF and HF radio calls. It has also been
designated part of the Global Maritime Distress and Safety System (GMDSS). This new
service allows you to initiate or receive distress, urgency, safety and routine calls to or
from another vessel equipped with a DSC transceiver.
NOTE: You will need to have a Maritime Mobile Service Identity (MMSI) assigned to you
and entered into the radio before Digital Selective Calling features will work. Refer to the
Maritime Mobile Service Identity (MMSI) and the DSC Setup, Enter Your User MMSI
sections for more information.
NOTE: You will also need to have an optional-purchase GPS Receiver attached in order to
take full advantage of the DSC features of your radio.
WARNING: This radio is designed to generate a digital maritime distress and safety call to
facilitate search and rescue. To be effective as a safety device, this equipment must be used
only within communication range of a shore–based VHF marine Channel 70 distress and
safety watch system. The range of signals may vary, but under normal conditions, should be
approximately 20 nautical miles.
To select a DSC call type:
1. Press the DSC/MENU key to display the DSC Call Type List, which you will use to
select the desired DSC call type by rotating the CH/ENTER knob until the desired
call type is highlighted, then pressing the CH/ENTER to execute your selection.
2. Only 4 calls can be displayed on the LCD at the same time; use the Up or Down
Channel keys on the microphone handset or the CH/ENTER knob on the radio
base station to view all the call types, until the desired call type is selected. Use
the following table to make a specific type of DSC call. (DSC Call Type choices
are: LAST CALL, NEW CALL, GROUP, ALL SHIPS, CALL LOG, DISTRESS LOG, POS
REQUEST, EXIT.)