Process Automation Communication Protocols

AS-i – Actuator-sensor interface, a low level 2-wire bus establishing power and communications to basic digital and analog devices

BSAP – Bristol Standard Asynchronous Protocol, developed by Bristol Babcock Inc.

CC-Link Industrial Networks – Supported by the CLPA

CIP (Common Industrial Protocol) – can be treated as application layer common to DeviceNet, CompoNet,
ControlNet and EtherNet/IP

ControlNet – an implementation of CIP, originally by Allen-Bradley

DC-BUS – communication over DC power lines, originally by Yamar Electronics Ltd

DeviceNet – an implementation of CIP, originally by Allen-Bradley

DF-1 - used by Allen-Bradley ControlLogix, CompactLogix, PLC-5, SLC-500, and MicroLogix class devices

DirectNet – Koyo / Automation Direct proprietary, yet documented PLC interface


Ethernet Global Data (EGD) – GE Fanuc PLCs (see also SRTP)

EtherNet/IP – IP stands for “Industrial Protocol”. An implementation of CIP, originally created by Rockwell Automation

Ethernet Powerlink – an open protocol managed by the Ethernet POWERLINK Standardization Group (EPSG).

FINS - Omron’s protocol for communication over several networks, including ethernet.

FOUNDATION fieldbus – H1 & HSE

HART Protocol

HostLink Protocol, Omron’s protocol for communication over serial links.

Interbus, Phoenix Contact’s protocol for communication over serial links, now part of PROFINET IO

IO-Link, for sensors, actuators and such

MECHATROLINK – open protocol originally developed by Yaskawa, supported by the MMA

MelsecNet, and MelsecNet II, /B, and /H, supported by Mitsubishi Electric.

Modbus PEMEX

Modbus Plus

Modbus RTU or ASCII or TCP

OSGP – The Open Smart Grid Protocol, a widely use protocol for smart grid devices built on ISO/IEC 14908.1

OpenADR – Open Automated Demand Response; protocol to manage electricity consuming/controlling

Optomux – Serial (RS-422/485) network protocol originally developed by Opto 22 in 1982. The protocol was
openly documented[2] and over time used for industrial automation applications.

PieP – An Open Fieldbus Protocol

Profibus – by PROFIBUS International.


RAPIEnet – Real-time Automation Protocols for Industrial Ethernet

Honeywell SDS – Smart Distributed System – Originally developed by Honeywell. Currently supported by

SERCOS III, Ethernet-based version of SERCOS real-time interface standard

SERCOS interface, Open Protocol for hard real-time control of motion and I/O


Sinec H1 – Siemens

SynqNet – Danaher

TTEthernet – TTTech

MPI – Multi Point Interface