Application acknowledgement to an addressed binary message
Details:
Replacing by DAC 1 FI 1 (warning older AIS stations could still use DAC 1 FI 1)
| Parameters | Number of bits | Description |
|---|---|---|
| Message ID | 6 | Identifier for Message 6; always 6 |
| Repeat indicator | 2 | Used by the repeater to indicate how many times a message has been repeated. See § 4.6.1, Annex 2; 0-3; 0 = default; 3 = do not repeat any more |
| Source ID | 30 | MMSI number of source station |
| Sequence number | 2 | 0-3; see § 5.3.1, Annex 2 |
| Destination ID | 30 | MMSI number of destination station |
| Retransmit flag | 1 | Retransmit flag should be set upon retransmission: 0 = no retransmission = default; 1 = retransmitted |
| Spare | 1 | Not used. Should be zero |
| DAC | 10 | International DAC = 110 = 00000000012 |
| FI | 6 | Function identifier = 510 = 0001012 |
| DAC code of received FM |
10 | Recommended to be spare |
| FI code of received FM | 6 | |
| Text sequence number | 11 | Sequence number in the message being acknowledged as properly received 0 = default (no sequence number) 1-2 047 = sequence number of received FM |
| AI available | 1 | 0 = received but AI not available 1 = AI available |
| AI response | 3 | 0 = unable to respond 1 = reception acknowledged 2 = response to follow 3 = able to respond but currently inhibited 4-7 = spare for future use |
| Spare bits | 49 | Not used, should be set to zero, reserved for future use |
| Total number of bits | 168 | The resulting Message 6 occupies 1 slot |