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Capability reply

Introduction/Additional information: 

IFM 4 should be used by an application to reply (using Message 6) to a capability interrogation (IFM 3) function message. The reply contains the availability status of the application for each function identifier for the specified DAC.

The application should use an addressed binary message to reply to the interrogating application.

Permitted as from: 
16/06/2007
Registrant: 
ITU-R.M.1371-3
Physical link: 
AIS
Message number (0=VDES-VDE): 
6
DAC or VPFI: 
1
FI / Message ID: 
4
State: 
in force
State link: 
Capability reply
Number of slots (max): 
2
Last modified: 
08/06/2021 - 12:01
Details: 

Parameter

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 = 410 = 0001002

DAC code

10

IAI, RAI or test

FI availability 

128

FI capability table, pair of two consecutive bits should be used for every FI, in the order FI 0, FI 1, …..FI 63.
First bit of pair:
0 = FI not available (default)
1 = FI available.
Second bit of the pair: reserved for future use; should be set to zero

Spare 

126

Not used, should be set to zero, reserved for future use

Total number
of bits

352

The resulting Message 6 occupies 2 slots

FI capability table, pair of two consecutive bits should be used for every FI, in the order FI 0, FI 1, …..FI 63.
First bit of pair:
0 = FI not available (default)
1 = FI available.
Second bit of the pair: reserved for future use; should be set to zero