ACR Electronics Y1-03-0222, AIS-300 manual Serial Port Input/Output, Power up messages, Data

Data

A minimum keypad and display (MKD) unit, chart plotter or other display device may be connected to the Nauticast™-B AIS unit via the appropriate cable assembly. The default baud rate of the data link is 38.4k baud with 8 data bits, one stop bit and no parity.

The data interface conforms to IEC 61162-1.

VDM, VDO, ACA, ACS, ALR, TXT and ACK messages conform to NMEA 0183. Please refer to NMEA 0183 for full details of these AIS messages.

2.Serial Port Input/Output

There is one 9-pin serial port for data in RS232 format. There is one set of flying leads for data in RS422 format. Duplex capability is available from either or both ports.

The serial port interface(s) output:

At power-up, boot-loader and main application splash text screens including version numbers and memory status.

As a VHF Data Link Message (VDM) all incoming VHF Data Link (VDL) data received by the Nauticast™-B AIS.

The VHF data link own vessel (VDO) messages sent by the Nauticast™-B AIS over the VHF Data Link.

AIS regional channel assignment messages (ACA) received. These are derived from an incoming VHF Data Link message (message 22) or a DSC message.

AIS channel management information source (ACS) messages. Alarm messages (ALR, TXT).

The data interface will accept:

Personality programming messages

Alarm acknowledgement messages (ACK)

3.Power up messages

On power up, the unit will report details of the firmware versions residing in the unit.

4.VHF data link messages (NMEA 0183 VDM)

This sentence is used to transfer the receipt of a VHF Data Link (VDL) message on either AIS radio channel, as defined in ITU-R M.1371, using the “Six-bit” field type. The structure provides for the transfer of long binary messages by using multiple sentences. Data messages should be transmitted in as few sentences as possible. When a data message can be accommodated in a single sentence, it is not split.

VDM message format!--VDM,x1,x2,x3,a,s--s,x*hh<CR><LF> field 1 2 3 4 5 6

	Field		Format	Description
1		x		Total number of sentences needed to transfer the message1, 1 to 9
2		x		Sentence number1, 1 to 9
3		x		Sequential message identifier2, 0 to 9
4		a		AIS Channel, "A" or "B"3
5		s---s		Encapsulated ITU-R M.1371 radio message4
6		x		Number of fill-bits5, 0 to 5

NOTE 1 The length of an ITU-R M.1371 message may require the transmission of multiple sentences. The first field specifies the total number of sentences used for a message, minimum value 1. The second field identifies the order of this sentence in the message, minimum value 1. These cannot be null fields.

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Y1-03-0222 Rev. C