Hardware Installation
SYS TEC electronic GmbH 2003 L-1006e_2
5
Connection via the Low Voltage Terminal Block X103
The low voltage terminal block is located next to the voltage socket at
X102.
Ensure that the correct polarity is applied to the terminal block. The
GND-Connection is near X102.
The configuration of the Developmentboard is now complete.
2.3
The Physical Connection of the CAN Interface
The Developmentboard provides a DB-9 connector for the physical
CAN bus connection. The pin definition for the CAN plug P2 is
shown in the table below:
Pin
Pin description
2
CAN_L (dominant low)
3
CAN_GND
7
CAN_H (dominant high)
Figure 4:
Developmentboard DB-9 CAN Plug Pinout
The CAN bus cable can be either a twisted pair or a ribbon cable. A
120 Ohm termination resistor has to be connected to the cable
between CAN_H and CAN_L at both ends of the bus cable. The
Jumper JP112 on the Developmentboard must be open. The wave
resistance of the cable should be 120 Ohm. The wire diameter
depends on the cable length as shown in
Figure 5:
For cable extensions of more than 200 meters, it is recommended to
optically isolate the CAN nodes.
Cable length
[m]
Maximum
Bitrate
[kbit/s]
Specific
resistance
[m
Ω
Ω
Ω
Ω
]
Wire diameter
[mm²]
0...40
1000
70
0,25...0,34
40...100
500
< 60
0,34...0,60
100...500
100
< 40
0,50...0,60
500...1000
20
< 26
0,75...0,80
Figure 5:
Recommended Parameters of the CAN Cable
