Fieldbus Communication • 147EtherNet/IP (Ethernet/Industrial Protocol)WAGO-I/O-SYSTEM 750ETHERNET TCP/IPto EtherNet/IP is easy to do.Data exchange takes place with the help of an object model.In this way, ControlNet, DeviceNet and EtherNet/IP have the same applicationprotocol and can therefore jointly use device profiles and object libraries.These objects enable plug-and-play interoperability between complex devicesof different manufacturers.In order to clarify the interrelationships between DeviceNet, ControlNet andEtherNet/IP, the following diagram presents the associated ISO/OSI referencemodel.Application device profiles(e.g. positioning couplers, semi-conductors, pneumatic valves)7 Applicationlayer CIP application object library6 PresentationlayerCIP data management services(explicit messages, I/O messages)5 Sessionlayer CIP message routing, connection managementCIP4 TransportlayerEncapsulationprotocolTCP UDP3 NetworklayerDeviceNet or ControlNettransport(transmission control,addressing) IP2 Data LinklayerCAN (CSMA/NBA) orControlNet (CTDMA)Ethernet(CSMA/CD)1 PhysicallayerDeviceNet or ControlNetphysical interfaceEthernetphysical interfaceETHERNET/IP4.3.2 Characteristics of the EtherNet/IP Protocol SoftwareLevel 1 Level 1: Explicit Messages ServerLevel 2 Level 2: Level 1 + I/O Messages Server• Unconnected Message Manager (UCMM) Client and Server• 128 Encapsulation Protocol sessions• 128 Class 3 or Class 1 Connections combinedClass 3 connection – explicit messages (connection oriented,client and server)Class 1 connection – I/O messages (connection oriented, clientand server)
