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Temposonics
®
MH Digital
Operating Manual
I
18
I
Baud rate setting:
Data source
COB-ID
Data
Destination
Controller
0x7e5
04; 01; 00; 00; 00; 00; 00; 00
Sensor
Controller
0x7e5
13; 00;
02*
; 00; 00; 00; 00; 00
Sensor
Sensor
0x7e4
13; 00; 00; 00; 00; 00; 00; 00
Controller
* Table Index
After sending ,save network parameter’ command and with following power on of the sensor
the baud rate setting becomes active. To save the baud rate following command will be send:
Data source
COB-ID
Data
Destination
Controller
0x7e5
17; 00; 00; 00; 00; 00; 00; 00
Sensor
Sensor
0x7e4
17; 00; 00; 00; 00; 00; 00; 00
Controller
SAE J1939
In the SAE J1939 specification, the maximum length of the network is limited to 40 meters and the baud rate is fixed to 250 kBit/sec. This
means that these parameters don‘t require setting during integration of the sensor.
Furthermore, the number of nodes is limited to 30 ECUs (Electronic Control Units). However, each ECU can control several CAs (Controller Ap-
plications). In total, an overall number of 253 Controller Applications can be realized in the network.
NMT (Network Management)
SAE J1939 supports extended network management. This management requires network registration (Address Claiming) by the bus sharing
units with a unique address prior to starting the system. The regular bus operation is started only after all bus sharing units have logged in suc-
cessfully. During operation, the correct address assignment is checked continuously. During operation, a new source address can be assigned.
In addition to the source address, each bus sharing unit is provided with a unique name for identification in the network and for prioritization of
the address determination. The name conventions are designed according to the SAE J1939/81 specification and composed as follows:
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Identity Number
Manufacturer
Code
ECU
Instance
Function
Instance
Function
Reserved
Vehicle
System
Vehicle
System
Instance
Industry
Group
Arbitrary
Address
Capable
Fig: structure on user in network acc. to J 1939
J1939: Setting the Source Address (sensor label: 07 20 01 23)
Data source
COB-ID
Data
Destination
Controller
0x10ff54d4
01
;
nSA*
; 23; 01; 20; 07; 00; 00
Transducer
Transducer
No response
Controller
* nSA: new Source Address
CANopen
J1939
The setting of the nSA can‘t last longer than 750 ms, otherwise a timeout will occur.