The CANopen Bootup Message is sent by a CANopen device when it starts. This is done to indicate to all other devices in the network that it is ready to communicate by other CANopen services. Although it may sound simple, there are preconditions that need to be met before a bootup message can be sent. The CAN-ID of the bootup messages depends on the CANopen node-ID of the device. That is why the device must have a valid node-ID between 1 and 127 in order to transmit a bootup message. Therefore, devices without a defined node-ID or without any switches to set the node-ID must use a dynamic Node-ID configuration by Layer Setting Services (LSS).
CAN-ID and CAN data
Anyway, we only discuss the case with a valid node-ID for now.
The CAN-ID of a bootup message is 0x700 + node-ID. That means that the CAN-IDs are located in the range between 0x701 and 0x77f. Each CANopen bootup message has a length of 1 byte. The value of this one byte is always 0x00. The same CAN-ID but different data are used by CANopen Heartbeat or Node Guarding messages.
Continue reading “CANopen Bootup Message”