Some fieldbuses such as DeviceNet, ControlNet and EtherNet/IP work in the application layer with the Common Industrial Protocol (CIP), which forms the interface between the deterministic fieldbus world and the non-deterministic IP world such as the Internet. The CIP protocol lies above the transport layer and extends the pure transport services with communication services for automation technology. These include services for cyclic, time-critical and event-driven data traffic.
The CIP protocol is a network-independent application protocol that works independently of the transmission medium and does not affect the routing ofIP networks. Control devices can access common device profiles and object libraries via the CIP protocol. The CIP-Safety version adds safety functions to the CIP protocol.