There are several widely used communication protocols in industrial automation and process instrumentation.
Here are some of the most popular ones:
- HART (Highway Addressable Remote Transducer)
- PROFIBUS (Process Field Bus)
- PROFINET (Process Field Net)
- EtherNet/IP (Ethernet Industrial Protocol)
- Foundation Fieldbus
- OPC (OLE for Process Control)
- Industrial Ethernet
- AS-Interface (Actuator Sensor Interface)
- CC-Link (Control & Communication Link)
- SERCOS (SErial Real-time Communication System)
- BACnet (Building Automation and Control Networks)
- MQTT (Message Queuing Telemetry Transport)
- IEC 60870-5-104
- DNP3 (Distributed Network Protocol)
- IEC 61850
- M-Bus (Meter-Bus)
- P-Net (Process-NET)
- EtherCAT (Ethernet for Control Automation Technology)
HART (Highway Addressable Remote Transducer)
HART is widely used in industrial automation to transmit and receive digital information using analog wiring between smart devices and control or monitoring systems.
Modbus is one of the earliest protocols used in industrial automation and is still popular due to its simplicity. Modbus can be used over serial communication (Modbus RTU and Modbus ASCII) and Ethernet (Modbus TCP/IP).
PROFIBUS (Process Field Bus)
PROFIBUS (Process Field Bus) is a standard for Fieldbus communication in automation technology which supports a wide range of equipment from various vendors.
PROFINET (Process Field Net)
PROFINET (Process Field Net) is an open standard for Industrial Ethernet and the successor of PROFIBUS. It provides real-time data exchange and integration with IT systems.
EtherNet/IP (Ethernet Industrial Protocol)
EtherNet/IP (Ethernet Industrial Protocol) is an open standard that uses the Common Industrial Protocol over Ethernet. It was developed by Rockwell Automation and is now managed by the ODVA.
Foundation Fieldbus is a digital protocol for process automation that provides advanced features like distributed control, complex block functions, and support for HSE (High-Speed Ethernet).
OPC (OLE for Process Control)
OPC is a series of standards and specifications for industrial telecommunication. OPC UA (Unified Architecture) is the latest version, offering platform-independent data exchange.
DeviceNet is a network protocol that provides connections between simple industrial devices (like sensors and actuators) and higher-level devices (like controllers and computers).
The CANopen protocol is used in embedded systems in automation. It is based on the Controller Area Network (CAN) and provides a wide range of communication services.
Industrial Ethernet is a broad term for the use of standard Ethernet protocols for industrial applications, often with ruggedized connectors and supports for real-time control and communication.
AS-Interface (Actuator Sensor Interface)
AS-Interface (Actuator Sensor Interface) is a simple protocol that connects basic field devices like actuators and sensors to a control system. It’s designed to be easy to use and inexpensive, and it operates on a master-slave configuration.
CC-Link (Control & Communication Link)
The CC-Link (Control & Communication Link) protocol was developed in Asia and is particularly popular in Japan. It allows devices from various manufacturers to communicate and exchange data.
SERCOS (SErial Real-time Communication System)
SERCOS (SErial Real-time Communication System) is a digital motion control bus that interconnects motion controls, drives, I/Os, sensors, and actuators for numerically controlled machines and systems. It is used in high-speed, real-time applications.
Interbus is a serial communication protocol used in the field of automation technology. It was developed by Phoenix Contact and has been in the market since 1987.
BACnet (Building Automation and Control Networks)
As the name suggests, BACnet was designed specifically for building automation and control, covering areas like heating, ventilation, and air-conditioning (HVAC) systems, lighting, security, and fire detection.
LonWorks is Developed by Echelon Corporation. LonWorks is a networking platform specifically created to address the needs of control applications. The platform is built on a protocol created by Echelon, known as LonTalk, which is considered one of the most robust network protocols for automation applications.
The KNX is an open standard for commercial and domestic building automation. KNX devices can manage lighting, blinds and shutters, HVAC, security systems, energy management, audio video, white goods, displays, remote control, etc.
WirelessHART is a wireless sensor networking technology based on the Highway Addressable Remote Transducer Protocol (HART). It was developed to allow for efficient communication in industrial settings where wiring can be difficult.
Zigbee is a wireless protocol designed for low-data rate, low-power applications and is often used for wireless control and monitoring applications. It’s particularly popular in consumer applications such as home automation.
MQTT (Message Queuing Telemetry Transport)
The MQTT is a simple and lightweight messaging protocol for use in cases where clients are of considerable network bandwidth constraints like in the case of IoT devices.
The IEC 60870-5-104 protocol is used for telecontrol (remote control) in electrical engineering and power system automation applications.
DNP3 (Distributed Network Protocol)
DNP3 is a standard for communicating to data acquisition and control equipment. It is used extensively in utilities such as electric and water companies.
The IEC 61850 is a standard for the design of electrical substation automation. It’s part of the International Electrotechnical Commission’s (IEC) Technical Committee 57 architecture for electric power systems.
The M-Bu is a European standard for remote reading of water meters or energy meters.
P-NET is used in industrial applications for process control. It is a field bus that provides real-time distributed control.
EtherCAT (Ethernet for Control Automation Technology)
The EtherCAT is an open high-performance Ethernet-based fieldbus system. This protocol is used to optimize process control applications and automation technology.
RS-232 is a standard for serial communication transmission of data. It formally defines signals connecting between a DTE (data terminal equipment) such as a computer terminal, and a DCE (data circuit-terminating equipment or data communication equipment), such as a modem.
RS-485 is a standard defining the electrical characteristics of drivers and receivers for use in serial communications systems. It is used in the building automation, industrial, and transportation industries.
Bluetooth is a wireless technology standard used for exchanging data between fixed and mobile devices over short distances. Industrial applications often use the more robust Bluetooth Low Energy (BLE) variant.
Wi-Fi is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access.
The application of each protocol depends on the requirements of the system such as speed, distance, network size, and the environment in which it is implemented.
Each protocol has its strengths and weaknesses, and the choice of which to use often depends on the specific requirements of the application, such as the need for real-time communication, the distance between devices, the complexity of the network, and the types of devices in the network.