This is the general information on the bus used by B&G (Brookes and Gatehouse) H2000 and H3000 systems

 

(Thanks to Tom Lafleur for all the information)
The bus is on a 28k8 speed, with odd parity and 2 stopbits
Green and White are the data lines, together with a 12V and a Ground signal.
 
Complete layout of a Serial TTL to Fastnet schematic(thanks to Tom for all the work)

This is an example string recorded on the bus:
ff 05 14 01 e7    1d 61 00 58    1c 51 01 df   87 06 00 be e8 e8  86 06 00 be e8 e8 a8

 

ff 05 14 01 e7    1d 61 00 58    1c 51 01 df   87 06 00 be e8 e8  86 06 00 be e8 e8 a8

ff = broadcast to all

05 = from wind/depth

14 = data in body part, 14hex = 20 dec = 20 databytes

01 = fastnet command, general data send

e7 = checksum header (header + checksum modulo 8 = 0)

a8 = full frame checksum(all data + checksum modulo 8 = 0

 

the first byte is the channel, the second is a mask to display the data? the rest is data
ff 05 14 01 e7 
 1d 61 00 58              1d = air temp C, format = 61, data = 0058 hex  ==  88dec  ==  88/10 =  8.8 graden celsius
 1c 51 01 df               1c = air temp F, format = 51, data =  01df hex  == 479dec  == 479/10 = 47.9 graden fahrenheit (= 8.8 graden celsius)
 87 06 00 be e8 e8      87 = barometric pressure, format = 06, raw data is unknown at this moment
 86 06 00 be e8 e8      86 = barometric pressure trend, format = 06, raw data is unknown at this moment
a8

41 91 02 71           41 = Boatspeed, format = 91, data = 0271 hex = 625 decimal =  625/100 = 6.25 knots

4d 61 00 04           4d = AWS knots, format = 61,  0004 hex = 4 dec  = 4 knots
 4f 61 00 02           4f  = AWS m/s, format = 61, 0002 hex = 2 dec  =  2ms (= 4 knots)

		Channel Number	Channel Number	Number of	Format
Channel Name	Short Name	Dec	Hex	Bytes		Node
Node Reset		00	00	0
??		01	01	4
Rudder Angle		11	0B	4		5
Linear 5		12	0C			0D
Linear 6		13	0D			0D
Linear 7		14	0E			0D
Linear 8		15	0F			0D
Linear 9		16	10			0D
Linear 10		17	11			0D
Linear 11		18	12			0D
Linear 12		19	13			0D
Linear 13		20	14			0D
Linear 14		21	15			0D
Linear 15		22	16			0D
Linear 16		23	17			0D
??		27	1B	6		10
Air Temperature degrees F		28	1C	4		5
Air Temperature degrees C		29	1D	4		5
Sea Temperature degrees °F		30	1E	4		1
Sea Temperature degrees °C		31	1F	4		1
Head/Lift Trend		39	27	4		30
Off Course		41	29	4		30
Tacking Performance		50	32	4		9
Reaching Performance		51	33	4		9
Heel Angle		52	34	6		5
Optimum Wind Angle		53	35	4		9
Depth Sounder Receiver Gain		54	36	4		1
Depth Sounder Noise		55	37	4		1
Linear 1		56	38	4		9
Linear 2		57	39	4		9
Linear 3		58	3A	4		9
Linear 4		59	3B	4		9
Boatspeed, Knots		65	41	4		1
Boatspeed, raw		66	42	4		1
??		71	47	5	??
Heading		73	49	4		x
Heading, Raw		74	4A	6		x
Apparent Wind Speed knots		77	4D	4		5
Apparent Wind Speed, raw		78	4E	6		5
Apparent Wind Speed m/s		79	4F	4		5
Apparent Wind Angle		81	51	4		5
Apparent Wind Angle, raw		82	52	6		5
Target TWA		83	53	4		9
True Wind Speed, knots		85	55	4		5
True Wind Speed M/S		86	56	4		5
??		87	57	4
True Wind Angle		89	59	4		5
??		90	5A	4
Average Speed, knots		100	64	4		1
Request for data		104	68	2
Course		105	69	4		5
Act for data		106	6A	4
True Wind Direction		109	6D	4		5
??		110	6E	4
Next Leg Apparent Wind Angle		111	6F	4		9
Next Leg Target Boat Speed		112	70			9
Next Leg Apparent Wind Speed		113	71	4		9
Timer		117	75	6		5
??		119	77
Target Boatspeed		125	7D	4		9
Velocity Made Good, K		127	7F	6		5
Dead Reckoning Distance		129	81	4		1
Leeway		130	82	6		5
Tidal Drift		131	83	4		9
Tidal Set		132	84	4		9
Upwash		133	85
Barometric Pressure Trend		134	86	6		5
Barometric Pressure		135	87	6		5
Battery Volts		141	8D	4		5
Heading on Next Tack		154	9A	4		x
Fore/Aft Trim		155	9B	6		5
Mast Angle		156	9C	4		5
Wind Angle to the Mast		157	9D	4		5
??		180	B4	6		10
??		182	B6	2
Depth Meters		193	C1	4		1
Depth Feet		194	C2	4		1
Depth Fathoms		195	C3	4		1
Stored Log, NM		205	CD	4		1
Trip Log, NM		207	CF	4		1
Dead Reckoning Course		211	D3	4		1
??		219	DB	4
Local Time		220	DC			9
Bearing Wpt. to Wpt, true		224	E0	4		9
Bearing Wpt. to Wpt., mag.		225	E1	4		9
Layline		226	E2			9
Bearing to Waypoint, rhumb true		227	E3	4		9
Bearing to Waypoint, rhumb mag.		228	E4	4		9
Bearing to Waypoint, G.C. true		229	E5	4		9
Bearing to Waypoint, G.C. mag.		230	E6	4		9
Distance to Waypoint, Rhumb		231	E7	4		9
Distance to Waypoint, G.C.		232	E8	8		9
Course Over Ground, True		233	E9	4		9
Course Over Ground, Mag.		234	EA	4		9
Speed Over Ground		235	EB	4		9
Vel. Made Good, Course		236	EC	4		9
Time to Waypoint		237	ED	4		9
Cross Track Error		238	EE	4		9
Remote 0		239	EF	4		9
Remote 1		240	F0	4		9
Remote 2		241	F1	4		9
Remote 3		242	F2	4		9
Remote 4		243	F3	4		9
Remote 5		244	F4	4		9
Remote 6		245	F5	4		9
Remote 7		246	F6	4		9
Remote 8		247	F7	4		9
Remote 9		248	F8	4		9
Next Waypoint Distance		250	FA			9
Time to Layline		251	FB			9

 

F/STAY	40
B/STAY	3
PT RUN	4
ST RUN	5
PT V1	6
ST V1	7
MN SHT	8
IFSTAY	9
LOAD 1	0A
LOAD 2	2A
LOAD 3	2B
LOAD 4	2C
LOAD 5	2D
LOAD 6	3D
LOAD 7	3E
LOAD 8	3F

 

 

Command		Bytes
00	This maybe a ARP request to see if my node address is in use. (used at start up) or  Reset Command
01	This appears to be a normal broadcast data command	Var
02	New Text ?
03	Sent from an NMEA FFD when NMEA data is there.    ff 60 02 03 50 47  or 47 50	2
04
05
06
07
08
09
0A	Used at start up??	2
0B
0C	This looks like a keep alive message, sent from FFD, 1 byte, ff 60 0C 6f	1
0D
0E
0F
10
20	Sector Alarm
21	Alarm, low alarm off, 60 01 21 ss 41 24 03 00 00 00	7
22	Alarm , hi alarm off , 60 01 22 ss 41 24 04 00 00 32	7
68	Request for data, reply is 6A, 2 bytes in request, 00 03, ask for version number	2
6A	Reply from a 68 request.. (FFD do not respond to this), replay is 4 bytes, 00 03 xx xx	4
C8	FFD send this when powering off
C9	Used to set light intensity in FFD and 20/20, two bytes of data, 1st: 0,1,2,4, 2nd byte always 20h, 0 = off, 4 = max	2
CA	Timer, 2 bytes, From FFD, start 10 = 05 60 CA ss FD, start 5, FE, start zero, FF
CB	Timer, 2 bytes, From FFD, Frezze, Run, Halt	2
CC	Timer Run, 2 bytes	2
CD	Request Damping value   01 60 CD ss 59	2
CE	Set/Get damping value   60  01 CE ss 41 21 00 5E   (94)	5
CF	From FFD, Manual Cal request, 01 60 CF  ss 41	2
D0	From FFD , send reaching correct, 05 60 D0 ss 59 04, respond is a D4	3
D1	Ask for cal 2?
D2
D3	Cal 1, 60 01 D3  ss 41 91 02 71, => 6.25, 41 = boatspeed,  Depth sends 60 01 D3 ss 41 06 00 f8 60 60 (respond to auto cal)	5 or 7
D4	Cal 2, respond to a D0, 60 05 D4 ss 59 54 04 00 00 00	7
D5	Cal 3
D6	Cal 4
D7
D8
D9
DA
DB
DC	Timer Freeze from FFD, 2 bytes   01 60 DC ss CF, respon from 01 is FD, 60 01 FD ss 35	2
DD
DE	Alarm low off, 01 60 DE ss 41
DF
E0
E1
E2	Alarm low on,  01 60 E2 ss 41 (boat speed)
E3
E4
E5		1
E6	Alarm off, ff 60 E6 ss
E7
E8
E9	Set/Get Cal value, 60 01 E9  ss 41 91 00 64   64=1.00	5
EA	Start a cal run, Boat speed, 01 60 EA  ss 41, ack with an FD from FFD	2
EB	Stop a cal run, Boat speed, 01 60 EB  ss 41, ack with an FD from FFD	2
EC	End Cal run, 01 60 EC ss 41 D3,  Depth sends 60 01 D3 ss 41 06 00 f8 60 60	3
ED	Cal    FD 60 ED  26
EE	From FFD, request Cal value 41,   01 60 EE   ss 41, 41 = boatspeed
EF	From FFD, ask what meter is connected. FD 60 EF ss 01, what on meter 01	2
F0	From FFD/Processor , to chang meters display, FD 60 F0 ss  01 03, set meter 01 to Mag Wind 03	3
F1	From FFD, Max Value, , 1st byte = seq, 2nd = 00 = Boat Speed, 01 = Wind Speed, FD 60 F1 01 00 or FD 60 03 01	2
F2	Set/Get max value, FD 60 F2  07 00 51 00 78, new max wind is 120 or 12.5	5
F3
F4
F5
F6
F7
F8
F9
FA	ack for FC??
FB
FC	Used on start up to assign channels, ie: this node will send this data	Var
FD	ack for FC from FFD, 1 byte look like sequence # to ACK	1
FE
FF	FFD send on start up,waiting to see if some one is on the net, 0 bytes	0