CAN in Automation Celebrates 30 Years

A look at what has been accomplished in the group’s three-decade history.

The Controller Area Network (CAN) in Automation (CiA) international users’ and manufacturers’ group turns 30 in 2022. Founded by six companies and two individuals, CiA has developed more than 25,000 pages of specifications, recommendations and application notes for the CAN community over the last 30 years. Now, the nonprofit association comprises more than 720 members. In the elevator market, CiA is well known because of the CANopen application profile for lift control systems. The CiA 417 document series specifies communication interfaces for several elevator controllers managing calls, doors and drives. The corresponding CANopen interfaces for units include panels, displays, drives, positioning sensors, etc. CANopen is an application layer using Classical CAN as a data link layer. The CANopen Lift profile enables controllers and units from different manufacturers to integrate easily.

CiA also develops CAN-related specifications and recommendations for other markets. Classical CAN is the first generation, introduced in 1986. The second generation is named CAN FD (flexible data-rate); it is currently used in passenger vehicles including those from Ford and General Motors. CiA already developed the third generation: CAN XL (extra-long). This development was finalized within the past year. The CAN XL protocol features data field lengths from 1 byte to 2048 bytes. The CAN SIC XL transceiver supports optionally PWM (plus-width modulation) coding and is able to transmit 10 Mbit/s and more. CAN XL hardware is able to run CAN legacy higher-layer protocols as well as TCP and UDP.

CiA is also well-known for the development of CANopen (CiA 301), CANopen FD (CiA 1301) and the associated CiA device, application and interface profiles. The CiA 402 profile for drives and motion controllers is widely in use as well. CANopen is an open application layer approach adopted in many industries, not just in the elevator business and industrial automation. It is used, for example, in medical devices, maritime electronics, commercial heavy-duty vehicles, laboratory equipment, satellites, rail vehicles and many other embedded control systems.

The CiA 610-1 (data link layer) and CiA 610-3 (physical layer) CAN XL documents have been forwarded to be integrated into the next edition of the ISO 11898-1 and the ISO 11898-2 standards. CiA has also submitted the CiA 604-1 CAN FD Light specification to ISO. It specifies the CAN FD responder node controlled by the CAN FD commander node, which complies with ISO 11898-1:2016. The CAN FD Light approach is intended for price-sensitive sensor and actuator applications, such as, smart LED headlights. In the elevator industry, it could be used instead of LIN or other low-cost serial communication links.

Additionally, the CiA 601-4 CAN SIC transceiver specification will be part of the next ISO 11898-2 edition. It specifies transceivers featuring signal improvement capability (SIC) by means of suppressing ringing on the network wires. This also allows running CAN FD or CAN XL not on optimized star and hybrid network topologies.

The scalability regarding the three CAN protocol generations and the selectable CAN physical layer technologies meets the requirements of many industries. The robustness and the communication reliability are additional advantages of CAN network solutions. And the price for a CAN interface is also very reasonable.