Generic Ethernet/IP and CIP Technical Information

Generic Ethernet/IP and CIP Technical Information

This wiki area was created for documenting technical aspects of CIP devices which include Ethernet/IP, ControlNet, and DeviceNET.

CIP is a complex object oriented device specification used for a common ground of exchanging information between devices. The general specifications are documented in the ODVA documents of "THE CIP NETWORKS LIBRARY". These manuals spell out the common aspects across of CIP devices. CIP allows extensions of the specifications by use of Vendor specific and Device specific Objects, Services, and Attributes. The vendor specific items can sometimes be difficult to find documented details about. So it is the purpose of this wiki to fill in the blanks.

If you are new to CIP (Ethernet/IP), you may find it to be quite overwhelming to understand. The specifications are very abstract making it hard to relate to a byte stream on a wire or implementation in code. In my experience, it is easier to grasp when you do not try to think of it as software implementation or a stream of bytes being exchanged between devices, but instead think of it as a device containing multiple objects that respond to commands.