Buoy position monitoring
| Parameter | Description |
| Introduction/Additional information | Buoy position monitoring |
| Registrant | Trinity House |
| Message number | 6 |
| DAC | 235 |
| FI | 20 |
| State | In force |
| Number of slots (max) | 1 |
| Permitted as from | 1/4/2019 |
Details:
| Parameter | Number of bits | Description |
| Message ID | 6 | Message identifier, always 6. |
| Repeat Indicator | 2 | Used by the repeater to indicate how many times a message has been repeated.
0 – 3; default = 0; 3 = do not repeat any more. |
| Source ID | 30 | The AtoN MMSI number |
| Sequence Number | 2 | 0-3 |
| Destination ID | 30 | Destination MMSI number |
| Retransmit Flag | 1 | Retransmit Flag should be set upon retransmission:
0 = no retransmission = default 1 = retransmitted. |
| Spare | 1 | Not used, set to ‘0’ |
| DAC | 10 | UK & NI area code – set to 235 |
| FI | 6 | Function identifier – set to 20 |
| Station name | 204 | The AtoN name |
| UTC Day | 5 | 1-31
0=not available = default |
| UTC Hour | 5 | 0-23
24 = not available = default |
| UTC Minute | 6 | 0-59
60 = not available = default |
| Longitude | 28 | Longitude in 1/10 000 min (180°, East = positive (as per 2’s complement), West = negative (as per 2’s complement). 181 = not available = default) |
| Latitude | 27 | Latitude in 1/10 000 min (±90°, North = positive (as per 2’s complement), South = negative (as per 2’s complement). 91° = not available = default) |
| Off Position Status | 1 | 0 = on position, 1 = off position |
| Spare | 4 | Not used, set to 0 |
| TOTAL OF BITS. | 368 |
Note: The IALA ASM Collection is not an endorsement of any message, and is not an authority for any DAC/FI combinations