User Manual

Marine Systems
Aviation Recorders
Initial Issue
Aug. 23/10
165M1161--00
Page 1--3
AtoN AIS Introduction
1.1. System Overview
The Aid to Navigation (AtoN) Automatic Identification System (AIS) is designed to
be installed as an integral part of weather and navigation buoys to transmit warn-
ings, navigational, and meteorological data to approaching vessels. Two versions of
the AtoN AIS are available: Type 1 transmits output messages, while Type 3 trans-
mits and receives messages.
In its most basic form, the unit transmits a report with the AIS AtoN’s position in an
ITU--R M. 1371 message 21. When the unit contains a daughterboard or it interfaces
with the buoy’s navigational and weather instrumentation, additional messages
transmit navigational and meteorological data. A summary of all the messages pro-
cessed by the AIS AtoN are defined in this section.
The L3 PROTEC --D AtoN AIS provides all AtoN capabilites for use in an office
environment, such as a port authority.
1.2. AIS AtoN Messages
The AIS AtoN transmission schedule and VHF slot assignments are determined by a
competent authority and used to configure the AIS AtoN prior to activation and in-
stallation. At a minimum, the AIS AtoN transmits message 21 and can be configured
to transmit the optional messages 6, 8, 12, 14, 17, and 25. All of these messages
are specified in ITU-- R M.1371
. This section briefly describes each message.
Tab le 1--1. Summary o f AIS AtoN Messages
Msg
ID
Message T ype Slot
Length
Message Description/Application
6 Addressed Binary
Message
1to5
(varies)
Binary payload that contains the MMSI, usually of a base station,
which is designated to receive the message that is sent until it is
acknowledged; May contain information about the AtoN equipment,
such as meteorological and hydrological information that is obtained
from a daughterboard or external sensors
8 Broadcast Binary
Message
1to5
slots
(varies)
Binary payload that broadcasts to any equipment that can receive
it; May contain information about the AtoN equipment, such as met-
eorological and hydrological information that is obtained from a
daughterboard or external sensors
12 Addressed Safety
Related Message
1to5
slots
(varies)
Safety--related text that is addressed to a specific MMSI, usually a
base station; Message is sent until it is acknowledged; Warns of an
AtoN malfunction