Appendix c – can wiring practices, Motec sdc3 17 appendices, Can bus – MoTeC SDC3 User Manual
Page 19: Short can bus
MoTeC SDC3
17
Appendices
Appendix C – CAN Wiring Practices
NOTE! The factory CAN bus in the STi is already terminated. This information is provided as a reference for
adding extra devices to the bus.
The CAN bus should consist of a twisted pair trunk with 100R (0.25Watt) terminating resistors at each end of the
trunk.
The preferred cable for the trunk is 100R Data Cable but twisted 22# Tefzel is acceptable.
The maximum length of the bus is 16m (50ft) including the MoTeC CAN Cable (PC to CAN Bus Communications
Cable)
CAN Devices (such as MoTeC ADL, M800 etc) may be connected to the trunk with up to 500mm (20in) of twisted
wire.
The connector for the CAN Communications Cable may also be connected to the trunk with up to 500mm (20in)
of twisted wire and should be within 500mm of one end of the trunk. If desired two CAN Cable connectors may be
used so that the MoTeC CAN Cable may be connected to either side of the vehicle. Both connectors must be
within 500mm of each end of the trunk.
CAN-LO
CAN-HI
10
0R
10
0R
CA
N-LO
CA
N-HI
CAN
Device
500mm
Max
CAN-LO
CAN-HI
CAN Cable
Connector
500mm
Max
<< CAN Bus >>
500mm Max
100R Terminating
Resistors at each
end of the CAN Bus
CA
N-LO
CA
N-HI
CAN
Device
CA
N-LO
CA
N-HI
CAN
Device
0V
8V
5
4
3
1
These w ires must be Tw isted
Minimum one twist per 50mm (2in)
Short CAN Bus
If the CAN Bus is less than 2m (7ft) long then a single termination resistor may be used. The resistor should be
placed at the opposite end of the CAN Bus to the CAN Cable connector.