
Inertial Measurement Unit IMUF99*B20
J1939 Interface Description
2
02
2-
06
25
The following table explains the 29 bit identifier of the example above.
6.3
Address Claiming
As defined in the J1939 standard the sensor supports the dynamic address claiming. To switch
off this function the arbitrary bit in the J1939 name (Parameter index 0x02) should be set to
zero.
The sensor starts the claiming with the default node address 128 (0x80) (Parameter Index
0x01). If an address conflict with a higher prior node occurs the network management will
change the node address automatically using his internal address claimed table. In this table
the sensor registers all claimed addresses from other nodes. The table will be cleared on a
reset. After a conflict the new claimed address will be saved in the parameter set and used on a
restart.
If the dynamic claiming is not active or no free node address is available the sensor will use the
null address 254. The null address is not saved in the parameter set: After a restart the sensor
will use the last claimed address. The Parameter Group Number (PGN) 0x00FED8 "Com
-
manded Address" is not supported.
6.4
Process Data (PD)
After the sensor has claimed a node address the measured inclination values will be send auto
-
matically with a "Proprietary B" PGN message. The priority, the PGN and the transmission rate
are changeable in the parameter mode. It's also possible to request the process data message
with the "Request" PGN 0x00EAnn.
Example Request PGN 0x FF 01:
*: placeholder, necessary
nn: destination address -> sensor node adress
rr: source address
xx: unused, bytes optional
Bit
29
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0 9 8 7 6 5 4 3 2 1
Byte 4
3 (PDU format)
2 (destination address)
1 (source address)
Value 1
1 1 0 0 1 1 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 1 1 0 0 1 0
0x
1
0xC
0xE
0xA
0x8
0x0
0x3
0x2
0x1CEA8032
Table 6.3
Identifier
Data Bytes
Priority PGN
Source
address
1
2
3
4
5
6
7
8
Requested PGN
*
0x00EAnn
rr
01
FF
00
xx
xx
xx
xx
xx
Table 6.4
Note
Requested PGN: LSB first!