IALA

Marine traffic signal

Marine traffic signal

 

Parameter No of bits Description
Message ID 6 Identifier for Message 8; always 8.
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.
Spare 2 Not used. Set to zero.
IAI 16 DAC =001; FI = 19
Message Linkage ID 10 A source specific running number, unique across all binary messages equipped with Message Linkage ID. Used to link additional information to the message by a Text Description message. The Message Linkage ID, source MMSI and message FI uniquely identifies the sent message.

1 – 1,023

0 = not available = default

Name of Signal

Station

120 Maximum 20 characters 6 bits ASCII, as defined in ITU-R M. 1371-3, Table 44

“@@@@@@@@@@@@@@@@@@@@” = not available = default

Position of Station,

Longitude

25 Longitude in 1/1,000 min, ±180 degrees as per 2’s complement (East = positive, West = negative).

181 = not available = default

Position of Station,

Latitude

24 Latitude in 1/1,000 min, ±90 degrees as per 2’s complement (North = positive, South = negative).

91 degrees = not available = default

Status of Signal 2 0 = not available = default

1 = In regular service

2 = Irregular service

3   reserved for future use

Signal in Service 5 (see Table 8.2)
Time of next Signal Shift   Time of next Signal Shift in UTC
UTC Hour 5 0 – 23

24 = not available = default

25-31 not used

UTC Minute 6 0 – 59

60 = not available = default

61-63  not used

Expected Next Signal 5 (see Table 8.2)
Spare 102 Not used. Set to zero.
Total 360 Occupies 2 slots

 

 

Table 8.2

Signal in Service[1]

 

Value Description
0 Not available = default
1 IALA port traffic signal 1: Serious emergency – all vessels to stop or divert according to instructions.
2 IALA port traffic signal 2: Vessels shall not proceed.
3 IALA port traffic signal 3: Vessels may proceed. One way traffic.
4 IALA port traffic signal 4: Vessels may proceed. Two way traffic.
5 IALA port traffic signal 5: A vessel may proceed only when it has received specific orders to do so.
6 IALA port traffic signal 2a: Vessels shall not proceed, except that vessels which navigate outside the main channel need not comply with the main message.
7 IALA port traffic signal 5a: A vessel may proceed only when it has received specific orders to do so; except that vessels which navigate outside the main channel need not comply with the main message.
8 Japan Traffic Signal – I = “in-bound” only acceptable.
9 Japan Traffic Signal – O = “out-bound” only acceptable.
10 Japan Traffic Signal – F = both “in- and out-bound” acceptable.
11 Japan Traffic Signal – XI = Code will shift to “I” in due time.
12 Japan Traffic Signal – XO = Code will shift to “O” in due time.
13 Japan Traffic Signal – X = Vessels shall not proceed, except a vessel which receives the direction from the competent authority.
14 – 31 (reserved for future use)