Aids to Navigation monitoring data
| Parameter | Number of bits | Description |
|---|---|---|
| Message ID | 6 | Identifier for this message 6; 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 | MMSI number of source Unit |
| Sequence Number | 2 | 0 – 3 |
| Destination ID | 30 | MMSI number of destination Unit. |
| 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 | Destination Area Code.
Default: 235 (UK & NI) or 250 (ROI) |
| FI | 6 | Function Identifier
Default: 10 for this GLA standard message |
| Analogue (internal) | 10 | 0.05- 36V 0.05V step Supply voltage to AIS Unit
0 – Not Used |
| Analogue (external –
from hardware analogue input No 1 |
10 | 0.05 – 36V 0.05V step
0 – Not Used |
| Analogue (external –
from hardware analogue input No 2 |
10 | 0.05 – 36V 0.05V step
0 – Not Used |
| Status Bits 0 / 1
(internal – same as the 5 LSBs of status bits from Message type 21) |
5 | 4 \ / 00 – no RACON installed; 01 – RACON not monitored
3 / \ 10 – RACON operational; 11 – RACON ERROR 2 \ / 00 – no light or no monitoring; 01 – Light ON 1 / \ 10 – Light OFF; 11 – Light ERROR 0 0 – Good Health, 1 – Alarm |
| Status Bits 0 / 1
(external – derived from hardware digital inputs) |
8 | 7 Digital Input Off/ / On
: : 0 Digital Input Off/ / On |
| Off Position Status | 1 | Off position or On position
0: On position 1: Off position |
| Spare | 4 | For future use. Should be zero. |
| TOTAL OF BITS. | 136 | Occupies 1 slot. |