ACR Electronics ACR-AIS-300 Manual De Usuario
19 of 25
Y1-03-0222 Rev T4T4
VDO Message number
VDO Message description
AIS Target Display Information
13
Safety Related Acknowledgement
18
Standard Class B position report (Includes MMSI, SOG, position accuracy, lat,
long, COG, true heading,)
long, COG, true heading,)
24a
Class B “CS” Static data Part A (Includes MMSI and vessel name)
24b
Class B “CS” Static data Part B (MMSI, ship type, cargo type, call sign, ship
dimensions)
dimensions)
5.6 Regional Assignment Channel Assignment Message
(NMEA
(NMEA
0183
ACA)
An NAUTICAST-B unit can receive regional channel management information in two ways: ITU-R M.1371
message 22 or a DSC telecommand received on channel 70. Channel management information is applied
based upon the actual location of the AIS device. An AIS unit is “using” channel management information when
the information is being used to manage the operation of the VHF receiver and/or transmitter inside the AIS unit.
This sentence is used both to enter and obtain channel management information. When sent to an AIS unit, the
ACA sentence provides regional information that the unit stores and uses to manage the internal VHF radio.
When sent from an AIS unit, the ACA sentence provides the current channel management information retained
by the AIS unit. The information contained in this sentence is similar to the information contained in an ITU-R
M.1371-1 message 22. The information contained in this sentence directly relates to the Initialisation Phase and
Dual Channel Operation and Channel Management functions of the AIS unit as described in ITU-R M. 1371.
message 22 or a DSC telecommand received on channel 70. Channel management information is applied
based upon the actual location of the AIS device. An AIS unit is “using” channel management information when
the information is being used to manage the operation of the VHF receiver and/or transmitter inside the AIS unit.
This sentence is used both to enter and obtain channel management information. When sent to an AIS unit, the
ACA sentence provides regional information that the unit stores and uses to manage the internal VHF radio.
When sent from an AIS unit, the ACA sentence provides the current channel management information retained
by the AIS unit. The information contained in this sentence is similar to the information contained in an ITU-R
M.1371-1 message 22. The information contained in this sentence directly relates to the Initialisation Phase and
Dual Channel Operation and Channel Management functions of the AIS unit as described in ITU-R M. 1371.
5.6.1. ACA Message Format
$--ACA,x,llll.ll,a,yyyyy.yy,a,llll.ll,a,yyyyy.yy,a,x,xxxx,x,xxxx,x,x,x,a,x,hhmmss.ss
field 1 2 3 4 5 6 7 8 91011121314 15
Field
Format
Description
1
x
Sequence Number , 0 to 9
2
IIII, II, a
Region Northeast corner latitude – N/S
3 yyyyy.yy,a
Region
Northeast corner longitude – E/W
4
IIII, II, a
Region Southwest corner latitude – N/S
5 yyyyy.yy,a
Region
Southwest corner longitude – E/W
6
x
Transition Zone Size
7 xxxx Channel
A
8
x
Channel A bandwidth
9 xxxx Channel
B
10
x
Channel B bandwidth
11
x
Tx/Rx mode contro
12
x
Power level control
13 a
Information
source
14 x
In-Use
Flag
15
hhmmss.ss
Time of "in-use" change
5.7 Channel management information source messages
(NMEA 0183 ACS)
(NMEA 0183 ACS)
This sentence is used in conjunction with the ACA sentence. This sentence identifies the originator of the
information contained in the ACA sentence and the date and time the AIS unit received that information.
information contained in the ACA sentence and the date and time the AIS unit received that information.