CANBus (Controller Area Network) is a vehicle bus standard designed to allow smart devices to communicate with each other through a robust, low-cost message-based protocol. CAN was developed by Robert Bosch in 1986 and was originally designed for multiplex electrical wiring within cars to save on copper, but is now used in many other applications such as the elevator industry.
Unlike a traditional network such as USB or Ethernet, CAN does not send large blocks of data point-to-point from node A to node B under the supervision of a central bus master. In a CAN network, many short messages like temperature or RPM are broadcast to the entire network, which means that there is data consistency in every node or ECU of the system.
CAN is a multi-serial bus standard for connecting nodes. Two or more nodes are required on the CAN network to communicate.
The complexity of the node can range from a simple I/O device up to an embedded computer with a CAN interface and sophisticated software.
The node may also be a gateway allowing a standard computer to communicate over a USB or Ethernet port to the devices on a CAN network.
CAN provides the basis for communication but does not provide much more. The CAN standard does not specify how to handle messages larger than 8 bytes or how to decode raw data. A set of standardized protocols exist to further define how data is communicated between nodes on a given network. CANOpen is an example of a common standard which is widely used in industrial automation and elevator applications.
With the rise of cloud computing and Internet of Things (IoT), the adoption of CANBus will increase in all relevant industries including the elevator industry where the data from sensors located in the elevator shaft and cabin will provide data allowing for predictive and preventative maintenance.