What is CANopen?
Reading about CANbus, one definitely comes across the term "CANopen." It is just a CAN-based communication system. CANopen in fundamental terms can be defined as the communication language where CAN-Bus is used as a transmission medium. As for the general understanding of the information, both the sender and the receiver need to agree on the same language standard.
Like CAN Bus, a lower-level protocol system involving the Physical layer and the Data link layer, CANopen is a higher-level protocol system that defines the upper five layers of the protocol model. Involving Network, Transport, Session Presentation, and Application Layers.
All the layers perform a discrete function on the CAN Bus.
(as described by https://www.can-cia.org/canopen/)
CANbus succeeded in finding applications in most industries, but to enable CANbus application to more fields, CANopen was designed. Initially designed for motion-oriented machine control systems, CANopen today finds application in various fields, such as: