CANopen device switch-off and switch-on

CiA 320 specifies services and protocols to switch-off and to switch-on CANopen devices.

Especially in battery-powered CANopen networks it is desired to save energy. CANopen devices capable to be switch-off by means of messages via CAN allow depending on the internal state to be switched-off. Of course, when needed they can be waked-up via CAN. Typical applications include light electric vehicles (CiA 454), add-on modules for special-purpose cars (CiA 447), service robots, or any other application that operate on a limited amount of energy, and in which energy management is therefore essential.

The CiA 320 services enable the power management master (PM master), which is residing at the active CANopen NMT master, to control the local Sleep finite state automaton (FSA) and the remote Sleep FSA of all power management devices (PM devices) in the network. The PM master protocol uses messages mapped to CAN data frames in classical base frame format (CBFF) with the CAN-ID 691h to send commands to PM devices. PM devices respond with messages mapped to CBFF (Classical CAN Frame Format) with the CAN_ID 690h, or the EMCY write protocol as specified in CiA 301 to transmit requests to the PM master. Good to know: The CANopen parameter 117Fh provides information about the reason for CANopen devices to stay awake or to request sleep.

CiA 320 has been released CiA-internally as Draft Standard Proposal. It will be reviewed after one year, when experiences have been made by the first implementations. Members can download the specification free-of-charge.