Raymarine RAY50, Инструкция по установке и эксплуатации

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3.8 System protocols
Your product can send and receive position
information, e.g. latitude and longitude using any of
the following protocols:
• SeaTalk ng
• NMEA 2000
• NMEA 0183
Using these protocols enables your radio to send
position information to other devices in your system
whenever it receives:
• a response to a DSC position request.
• a DSC distress call
Note: You may find that your product or system
does not use all of the protocols described in this
section.
Seatalk ng
SeaTalk ng (Next Generation) is an enhanced protocol
for connection of compatible marine instruments
and equipment. It replaces the older SeaTalk and
SeaTalk
2 protocols.
SeaTalk ng utilizes a single backbone to which
compatible instruments connect using a spur. Data
and power are carried within the backbone. Devices
that have a low draw can be powered from the
network, although high current equipment will need
to have a separate power connection.
SeaTalk ng is a proprietary extension to NMEA 2000
and the proven CAN bus technology. Compatible
NMEA 2000 and SeaTalk / SeaTalk
2 devices can
also be connected using the appropriate interfaces
or adaptor cables as required.
NMEA 2000
NMEA 2000 offers significant improvements over
NMEA 0183, most notably in speed and connectivity.
Up to 50 units can simultaneously transmit and
receive on a single physical bus at any one time,
with each node being physically addressable. The
standard was specifically intended to allow for
a whole network of marine electronics from any
manufacturer to communicate on a common bus via
standardized message types and formats.
NMEA 0183
The NMEA 0183 Data Interface Standard was
developed by the National Marine Electronics
Association of America. It is an international
standard to enable equipment from many different
manufacturers to be connected together and share
information.
The NMEA 0183 standard carries similar information
to SeaTalk. However it has the important difference
that one cable will only carry information in one
direction. For this reason NMEA 0183 is generally
used to connect a data receiver and a transmitter
together, e.g. a compass sensor transmitting
heading to a radar display. This information is
passed in ‘sentences’, each of which has a three
letter sentence identifier. It is therefore important
when checking compatibility between items that the
same sentence identifiers are used some examples
of which are:
• VTG - carries Course and Speed Over Ground
data.
• GLL - carries latitude and longitude.
• DBT - carries water depth.
• MWV - carries relative wind angle and wind speed
data.
NMEA Baud rates
The NMEA 0183 standard operates at a number
of different speeds, depending upon the particular
requirement or equipment capabilities. Typical
examples are:
• 4800 baud rate. Used for general purpose
communications, including FastHeading data.
• 38400 baud rate. Used for AIS and other high
speed applications.
Planning the installation
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