ACR Electronics AIS-300, Y1-03-0222 manual VDL Message number VDM Message description

NOTE 2 The sequential message identifier provides a message identification number from 0 to 9 that is sequentially assigned and is incremented for each new multi-sentence message. The count resets to 0 after 9 is used. For a message requiring multiple sentences, each sentence of the message contains the same sequential message identification number. It is used to identify the sentences containing portions of the same message. This allows for the possibility that other sentences might be interleaved with the message sentences that, taken collectively, contain a single message. This shall be a null field for messages that fit into one sentence.

NOTE 3 The AIS channel is indicated as either “A” or “B”. This channel indication is relative to the operating conditions of the AIS unit when the packet is received. This shall be a null field when the channel identification is not provided. The VHF channel numbers for channels “A” and “B” are obtained by using a “query” (See IEC 61162-1, clause 5.3.2) of the AIS unit for an ACA sentence.

NOTE 4 This field supports a maximum of 62 valid characters for messages transferred using multiple sentences, and 63 valid characters for messages using a single sentence.

NOTE 5 This cannot be a null field. (See “x4” in IEC 61162-1, clause 5.3.3).

VDM message types

For example, the information contained in the s - - s portion of the VDM = Encapsulated ITU-R M.1371 radio message. Note that messages 5 and 19 may be sent as multi part messages using the x1, x2 and x3 parameters for message sequence control.

	VDL Message number	VDM Message description
	AIS Target Display Information
1, 2, 3, 9,18, 21		position report
4		base station report
5*		voyage related data
19*		Class B – extended data
	Safety message handling
12		addressed safety related
14		broadcast safety related
	External Application
	handling
6		binary addressed
8		binary broadcast
	System control
7		binary acknowledge (INFO)
10		UTC and data inquiry (INFO)
11		UTC and data response (INFO)
13		safety related ack (INFO)
15		interrogation (INFO)
16		assignment mode command (INFO)
17		DGNSS corrections (INFO)
20		data link management (INFO)
22		channel management (INFO)

*Note that messages 5 and 19 may be sent as multi part messages.

24

Y1-03-0222 Rev. C