EtherNet/IP
Introduction
Links
As of November 2008, The EtherNet/IP Specification consists of three parts: The Common Industrial Protocol (Volume 1 of the CIP Networks Library), the EtherNet/IP Adaptation of CIP (Volume 2), and the Integration of Modbus® Devices into a CIP Architecture (Volume 7).
Order Form for the SPEC ($1000) https://www.odva.org/spec-vid-ctsoftware-order-form/