EtherNet/IP® is based on Rockwell Automation’s Common Industrial Protocol (CIP). This defacto industry standard uses Ethernet (IEEE 802.3) datalink and physical layers, with TCP/IP and UDP/IP transport layers. Industry-specific messages have “unlimited data length and are “encapsulated” using standard components for Ethernet. No fragmentation protocol is necessary and it can be used in parallel with other well-known Internet protocols such as HTTP, FTP and SMTP.

CIP Sync adds real-time capability by basically mapping the IEEE 1588 Precision Clock Synchronization into the CIP object model. CIP Sync cycle time is typically around a millisecond. CIP Motion is another subset of this family of protocols, which is a set of application profiles designed to allow position, speed and torque loops to be closed within a drive.

EtherNet/IP node performance depends on operating system attributes such as task switch time, and TCP/IP stack attributes such as UDP-throughput. 16-bit processors are not recommended. Microcontrollers implementing this protocol should be 32-bits with at least 50 MHz clock frequencies. Random access memory (RAM) requirements depend on the number of connections and buffer sizes, and typically range from 32 to 256 kilobytes. Read only memory (ROM) requirements depend on the type of CIP profile implemented, and typically range from 64 to 128 kilobytes.