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