WABCO OptiTire System Description page 38

Components
6.6 CAN termination
1
2
A CAN connection should always consist of a path with a maximum of two defined ends. Termination
must be provided at each end by a terminating resistor. As a rule, the terminal resistor is located in the
connected CAN device.
A CAN network with more than two end resistors does not allow reliable communication. For this
reason it is necessary that additional devices are only operated with the resistor switched off. Devices
without resistance must be connected to the short end of a path (max. 1 m). On the picture shown an
EBS modulator and an OptiTire ECU are connected to the connectors 1 and 2 . TEBS automatically
switches off its termination due to the parameterisation.
For OptiTire it is necessary to switch off the termination via the Expert Mode in the diagnosis.
However, this is only necessary if four devices are connected. When using only three devices, the
termination remains in OptiTire and the free cable end is sealed with the supplied cap.
When using 449 944 XXX X (ECAS control box), termination does not have to be taken into account, as
the ECAS control box is not a CAN device.
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