True Heading AIS-CTRX - VHF Data Link Own Vessel Messages (NMEA 0183 VDO); Regional Assignment Channel Assignment Message (NMEA 0183 ACA); ACA Message Format

AIS-CTRX Class B AIS Transponder Manual
VHF data link own vessel messages (NMEA 0183 VDO)
This message describes the own vessel message being sent.
VDO Message Format
!--VDO,x1,x2,x3,a,s--s,x*hh<CR><LF>
Where
• x1 = Total number of sentences needed to transfer the message , 1 to 9
• x2 = Sentence number, 1 to 9
• x3 = Sequential message identifier, 0 to 9
• a = AIS Channel, "A" or "B"
• s - - s = Encapsulated ITU-R M.1371 radio message 4
• x = Number of fill-bits , 0 to 5
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,)
24a Class B “CS” Static data Part A (Includes MMSI and vessel
name)
24b Class B “CS” Static data Part B (Includes MMSI, ship type, cargo
type, call sign, ship dimensions)
Regional Assignment Channel Assignment Message (NMEA 0183 ACA)
An AIS-CTRX unit can receive regional channel management information in two ways: ITU-R M.1371
message 22 or a DSC telecommand received on channel 70,
ACA Message Format
$--ACA,x,llll.ll,a,yyyyy.yy,a,llll.ll,a1,y1y1y1y1y.y1y1,a2,x1,x2x2x2x2,x3,x4x4x4x4,
x5,x6,x7,a3,x8,hhmmss.ss*hh <CR><LF>
• x = Sequence Number , 0 to 9
• IIII, II, a = Region Northeast corner latitude – N/S
• yyyyy.yy,a1 = Region Northeast corner longitude – E/W
• llll.ll,a = Region Southwest corner latitude – N/S
• y1y1y1y1y1.y1y1,a2 = Region Southwest corner longitude – E/W
• x1 = Transition Zone Size
• x2x2x2x2 = Channel A
• x3 = Channel A bandwidth
• x4x4x4x4 = Channel B
• x5 = Channel B bandwidth
• x6 = Tx/Rx mode control
1.1E 28 LD2103