CANOPEN bus maximum length and maximum number of nodes  ?

CANopen is a high-level protocol based on CAN (Control Area Network) serial bus system and CAL (CAN Application Layer).

The CANopen communication protocol CiADS-301 includes periodic and event-driven communication, which not only reduces the bus load to a minimum, but also ensures extremely short reaction times.

It enables high communication performance at lower baud rates, reducing electromagnetic compatibility issues and lowering cable costs.

The physical medium used by CANopen conforms to the ISO11898 standard and adopts a two-wire bus with a sub-drive mechanism and public feedback.

The maximum length of the bus depends on the communication speed and is specified as follows:

Theoretically, there can be up to 127 nodes. In practice, however, the maximum number of nodes depends on the performance of the CAN transceiver used.

The CAN bus line must be terminated with a 120 ohm (1%, 1/4W) resistor connected at each end between the CAN-L and CAN-H lines

The bus cable is a shielded cable with two pairs of twisted pairs: one pair of twisted pairs is connected to CAN-L and CAN-H respectively, and the other pair of twisted pairs is directly connected to GND.

 
When the device alarms, CANopen will start an Emergency message to inform consumers of the current device type and error code.