The compelling case for CANbus control

Edited by the Engineeringtalk editorial team May 19, 2005

Making the move to bus-based control is a big step, but the advantages are numerous: Morten Moller of Sensor-Technik UK examines what's in it for the user.

Twenty-first century vehicles where modular sensors and controls are connected to a network backbone are now possible thanks to the widely used CANbus.

You can throw away the wiring loom - and replace it with two wires.

Smart gauges and sensors can be directly connected to the CANbus.

Control modules can read/send data, display systems can read/log data and because it is a network, it is irrelevant where components are physically located.

Information display panels show the driver/operator what he needs to know.

Logging of information feeds the service system and panels display information where required, eg next to the valves on a tanker.

CANbus also has the bandwidth to cope with real time control as well as data collection.

What are the benefits of CANbus?.

First, there's lower cost production: one set of software, one system and one supplier on a standard communication system gives you flexibility; the same assembly can be set-up via the software to individual customer applications without having to change any hardware.

Different CANbus controllers are able to communicate with each other over the same bus, eg from engine to transmission, to the operator panel or any other controller.

CAN controllers can be linked together; for example, a controller on one vehicle can talk to another - you can add machinery on a tractor and it will work together.

Repeat working functions can be logged by simple selection, giving high repeatable quality of work.

Push switches and joysticks replace heavy or difficult levers, giving better driving comfort and better viewing as valve blocks, pipes etc are eliminated from the cab.

There's no vibration, mechanical shocks, fatigue, white finger etc, and the operator interface can be set up to individual applications.

Reductions in the number of mechanical components lead to lower failures.

As the operator panel electronically talks to the controller, removal of the hydraulics in the driver cab can be achieved, which is desirable as new European regulations come into force.

The controller can be mounted close to the hydraulic system, therefore reducing pipework.

CANbus can be linked with other equipment such as remote controls, video cameras and GPS (Global Positioning System) to track a vehicle and to ensure it only works where it has been allocated.

CANbus can bring together several systems, eg weighing systems, information logging, statistics, servicing reports, time per job etc.

Fast and low cost servicing and backup is another factor.

No more wasted investigation into why a vehicle has a problem; the fault diagnostic with complete error message will highlight the problem - and it's also available by mobile telephone.

Safety features and error detection can be added to ensure equipment cannot be overloaded or misused and only correct commands are executed.

In the event of misuse the process will be stopped and logged.

Finally, there's high reliability where it counts; the use of standard sensors at low cost, with no need for special sensors or new technology.

The input/output modules allow you to use already proven sensors which are tried and tested - although you can of course combine it with up-to-date CANbus sensors too.

A free 16-page guide from Sensor-Technik UK expands on all the points above.