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GX5500S
9 DIGITAL SELECTIVE CALLING
9.1 GENERAL
WARNING
The
GX5500S
is designed to generate digital maritime distress and
safety calls to facilitate search and rescue. To be effective as a safe-
ty 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 signal may vary, however under normal
conditions should be approximately 20 nautical miles.
Digital Selective Calling (DSC) is a semi-automated method of establishing a
radio call, it 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 as part of the Global Maritime Distress and
Safety System (GMDSS).
Digital Selective Calling allows mariners to instantly send a distress call with
GPS position (when connected to the transceiver) to the US Coast Guard and
other vessels within range of the transmission. DSC will also allow mariners to
initiate or receive Distress, Urgency, Safety, Routine, Position Request, Posi-
tion Report, Automatic Position Polling and Group calls to or from another
vessel equipped with a DSC transceiver.
NOTE
A DSC Warning sticker is included with
the
GX5500S
. To comply with FCC
regulations this sticker must be mount-
ed in a location that can be easily
v i e w e d f r o m t h e l o c a t i o n o f t h e
GX5500S
.
WARNING
STICKER
9.2
MARITIME MOBILE SERVICE IDENTITY (MMSI)
9.2.1 What is an MMSI?
An MMSI is a nine digit number used on marine transceivers capable of using
Digital Selective Calling (DSC). This number is used like a telephone number
to selectively call other vessels.