Application acknowledgement

Introduction/Additional information:

This IFM should be used by a ship or base station to acknowledge a binary message.
This IFM should be returned to the interrogating station only.

Permitted as from:

01/01/1998

Not to be used after:

01/04/2010

Registrant:

ITU-R.M.1371-1

Physical link:

AIS

Message number (0=VDES-VDE):

DAC or VPFI:

FI / Message ID:

State:

replaced

State link:

Number of slots (max):

Last modified:

29/01/2021 - 23:18

Details:

Replaced by DAC 1 FI 5 (warning older AIS stations could still use this one)

Parameter	Number of bits	Description
IAI/DAC code	10	See Annex 2, Table 20
Message sequence number	11	Sequence number in the message being acknowledged
Spare bits	3	Formula for inserting for spare bits
Total number of bits	24

Annex 2, Table 20

DAC	Function identifier	Resulting application identifier (binary)	Resulting application identifier (hex)	Description
1	0	0000 0000 0100 0000	40	Use of these messages, e.g. for aids-to-navigation, VTS, search and rescue, should be as defined in Annex 5
1	1	0000 0000 0100 0001	41
1	2	0000 0000 0100 0010	42
1	3	0000 0000 0100 0011	43
1	...	0000 0000 01XX XXXX	...
1	63	0000 0000 0111 1111	007F