Text description
Text description – (addressed)
| Parameter | No 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.
0 – 3 0 = default 3 = do not repeat anymore |
| Source ID |
30 |
MMSI number of source station. |
| Sequence Number |
2 |
0 – 3; refer to § 5.3.1, Annex 2 of ITU-R M.1371-3. |
| 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. Set to zero. |
| IAI |
16 |
DAC = 001; FI = 30
(See Rec. ITU-R M.1371-3, Annex 5, § 2.1. |
| Message Linkage ID |
10 |
Used to link the Text Description message with a main message. The Connection ID and source MMSI MID uniquely identifies the main message.
1 – 1,023 0 = not available = default |
| Text String |
6 – 930 |
Free text 1 – 155 characters 6-bits ASCII). If applicable, recommended to use IMO Standard Marine Communication Phrase (SMCP) (see IMO A.918(22)). Number of slots used should be minimized, refer to Table 14.4. |
| Spare |
0 |
Not used. Set to zero. |
| Total |
104 – 1028 |
Occupies 1 – 5 slots (see Table 14.4). |
Number of slots if sent as an addressed message
| Number of characters in the message | 1-6 | 7-43 | 44-81 | 82-118 | 119-155 |
|---|---|---|---|---|---|
| Number of slots used | 1 | 2 | 3 | 4 | 5 |