EtherNet/IP

EtherNet/IP wraps the Common Industrial Protocol (CIP) in standard TCP and UDP frames, so a robot controller sits on the same physical network as PLCs, drives, HMIs, and I/O blocks. Most FANUC, ABB, and Yaskawa controllers ship it as a factory option or add-on card.

In a working cell it usually plays two roles. Implicit I/O carries the fast, cyclic bit and register exchange used for handshakes with a line PLC like Allen-Bradley ControlLogix, while explicit messaging covers configuration reads, alarm queries, and one-off diagnostic pulls from an HMI or engineering laptop.

Reach for it when the plant standard is Rockwell, when the safety layer is going to run CIP Safety on the same wire, or when a cell controller needs a common protocol to talk to non-robot devices in the same station.

It rides on commodity Ethernet, which is a feature and a limit. Deterministic behavior depends on managed switches, VLAN segmentation, and IGMP snooping being set up correctly, since Class 1 implicit traffic is multicast and shares wire with anything else you drop on the segment.

Vendor add-on profiles (AOPs) differ by robot brand and by controller firmware, and the exposed tag structure isn't identical across FANUC, ABB, and Yaskawa. A profile that works with one firmware may need updating when the robot is upgraded, so keep the AOP version noted with the cell drawings.

Common commissioning pitfalls include duplicate node addresses, MTU mismatches on tagged VLANs, and connection ownership fights when two PLCs try to open Class 1 connections to the same robot. Bad handshake design is more often the cause of intermittent stops than the network itself.

Typical uses: passing part-present and job-done signals during machine tending or palletizing, reading payload or fault status from the robot into an HMI, and moving grip and vacuum commands to end-of-arm tooling that also speaks EtherNet/IP.