WaveSculptor 22 Motor Drive User`s Manual 18 April 2012

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8.1

USER'S MANUAL

WaveSculptor 22 Motor Drive

TRI88.004 ver 2

18 April 2012

CAN BUS AND LOW VOLTAGE

CAN NETWORK TOPOLOGY

The CAN bus is structured as a linear network, with short stubs branching from 'T' connectors on the main bus backbone to each device. The CAN bus data lines must be terminated at each end of the main bus with 120 ohm resistors between the CAN-H and CAN-L signals.

In the range of Tritium EV products, including the WaveSculptor 22, EV Driver

Controls, and BMS Pack Master, the CAN connections are implemented with an

'in' and an 'out' connector, therefore placing the 'T' on the device, resulting in a very short fixed-length stub on the circuit board of each device. This is ideal from a signal integrity and network performance point of view.

8.2

The WaveSculptor motor controller uses the CAN bus to receive commands and transmit telemetry, as well as to provide low-voltage DC power to operate the controller electronics.

Therefore, a basic system consists of three major components:

1. WaveSculptor motor controller

2. Driver controls interface to pedals, switches & gauges

3. Power supply (nominally 12V DC) to operate the system

Other components can also be added to the network. Items typically found in a solar electric vehicle would include:

4. LCD and other driver information displays

5. Battery management system

6. Multiple motor controllers

7. Datalogging and RF telemetry

CAN WIRING

The CAN data lines (CAN-H and CAN-L) must be implemented with twisted-pair wire for proper data integrity. The wire should have a characteristic impedance of

120 ohms.

Power should also be provided along the CAN cable, ideally with another twisted pair to minimise noise pickup. An overall shield can also be advantageous.

From a performance perspective, the optimal choice of cable is 7mm Devicenet

CANbus 'thin' cable, with 24AWG (data) + 22AWG (power) twisted pairs and a braided shield. Using this cable will result in a robust installation.

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