List of automation protocols. This is a list of communication protocols used for the automation of processes (industrial or otherwise), such as for building automation, power-system automation, automatic meter reading, and vehicular automation.

Process automation 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
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
DNP3 - a protocol used to communicate by industrial control and utility SCADA systems
DirectNet – Koyo / Automation Direct proprietary, yet documented PLC interface
EtherCAT
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
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
MPI – Multi Point Interface
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 devices
Optomux – Serial (RS-422/485) network protocol originally developed by Opto 22 in 1982. The protocol was openly documented and over time used for industrial automation applications.
PieP – An Open Fieldbus Protocol
Profibus – by PROFIBUS & PROFINET International (PI)
PROFINET - by PROFIBUS & PROFINET International (PI)
RAPIEnet – Real-time Automation Protocols for Industrial Ethernet
Honeywell SDS – Smart Distributed System – Originally developed by Honeywell.  Currently supported by Holjeron.
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
GE SRTP – GE Fanuc PLCs
Sinec H1 – Siemens
SynqNet – Danaher
TTEthernet – TTTech

Industrial control system protocols

Data Distribution Service from the Object Management Group
EPICS Channel Access and PV Access (PVA), particle accelerator control system framework
MTConnect
OPC Unified Architecture
Open Platform Communications, formerly OLE for process control

Building automation protocols

1-Wire – from Dallas/Maxim
BACnet – for Building Automation and Control networks, maintained by ASHRAE Committee SSPC 135.
BatiBUS - merged to KNX
C-Bus Clipsal Integrated Systems Main Proprietary Protocol
CC-Link Industrial Networks, supported by Mitsubishi Electric
DALI - Digital Addressable Lighting Interface specified in IEC 62386.
DSI -  Digital Serial Interface for the controlling of lighting in building, precursor to DALI.
Dynet -  lighting and automation control protocol developed in Sydney, Australia by the company Dynalite
EnOcean – Low Power Wireless protocol for energy harvesting and very lower power devices.
European Home Systems Protocol (EHS) - merged to KNX
European Installation Bus (EIB) named also Instabus - merged to KNX
INSTEON - SmartHome Labs Pro New 2-way Protocol based on Power-BUS.
KNX – Standard for building control.  Previously Batibus/EHS/EIB
LonTalk – protocol for LonWorks technology by Echelon Corporation
Modbus RTU or ASCII or TCP
oBIX - Open Building Information Exchange is a standard for RESTful Web Services-based interfaces to building control systems developed by OASIS.
UPB - 2-way Peer to Peer Protocol
VSCP - Very Simple Control Protocol is a free protocol with main focus on building- or home-automation 
xAP – Open protocol
X10 – Open standard for communication among electronic devices used for home automation (domotics)
Z-Wave - Wireless RF Protocol
Zigbee – Open protocol for Mesh Networks

Power system automation protocols

DNP3 – Distributed Network Protocol
IEC 60870-5
IEC 61850
IEC 62351 – Security for IEC 60870, 61850, DNP3 & ICCP protocols

Automatic meter reading protocols

ANSI C12.18
DLMS/IEC 62056
IEC 61107
M-Bus
OMS
Zigbee Smart Energy 2.0
Modbus
ANSI C12.21
ANSI C12.22

Automobile / Vehicle protocol buses
Controller Area Network (CAN) – an inexpensive low-speed serial bus for interconnecting automotive components
FlexRay – a general purpose high-speed protocol with safety-critical features
IDB-1394
IEBus
J1708  – RS-485 based SAE specification used in commercial vehicles, agriculture, and heavy equipment.
J1939 and ISO11783 – an adaptation of CAN for agricultural and commercial vehicles
Keyword Protocol 2000 (KWP2000) – a protocol for automotive diagnostic devices (runs either on a serial line or over CAN)
Local Interconnect Network (LIN) – a very low cost in-vehicle sub-network
Media Oriented Systems Transport (MOST) – a high-speed multimedia interface
Vehicle Area Network (VAN)
UAVCAN - a lightweight protocol for in-vehicle communication over CAN or Ethernet

See also

 Lists of network protocols
 Protocol converter
 Serial communication
 Vehicle bus

References

Industrial Ethernet
Control engineering
automation