Connecting the Industrial World: An Exploration of Communication Protocols in Automation and Instrumentation

To ensure perfect connectivity and data sharing between devices, controllers, and systems, industrial automation relies on an extensive variety of communication protocols. These protocols are critical in a variety of industries, providing solutions for different communication needs such as real-time data transmission, remote control, and process automation. 

Communication Protocols in Automation and Instrumentation

In this in-depth look at some of the most prominent communication protocols used in industrial automation, we’ll look at their characteristics, uses, and significance in the sector.

HART (Highway Addressable Remote Transducer)

  • HART is a widely used industrial automation protocol for sending digital data over analogue wiring between smart devices and control systems. 
  • Its ability to overlay digital communication on old analogue signals 4- 20 mA makes it compatible with current infrastructure, allowing intelligent devices to be seamlessly integrated.


  • Modbus, as one of the initially developed industrial automation protocols, is still used today due to its simplicity. 
  • It is versatile for a wide range of applications since it supports both serial communication (Modbus RTU and Modbus ASCII) and Ethernet (Modbus TCP/IP).

PROFIBUS (Process Field Bus)

  • PROFIBUS is a Fieldbus communication standard in automation that supports a wide range of equipment from many vendors. 
  • Its durability and adaptability have contributed to its extensive use in a variety of industrial contexts.

PROFINET (Process Field Net)

  • PROFINET, the successor to PROFIBUS, is an open industrial Ethernet standard. 
  • It is appropriate for advanced industrial applications since it allows for real-time data interchange and seamless connection with IT systems.

EtherNet/IP (Ethernet Industrial Protocol)

  • Rockwell Automation created EtherNet/IP, an open standard that uses the Common Industrial Protocol over Ethernet and is presently controlled by the ODVA.
  • It lays out the framework for communication in industrial automation systems.

Foundation Fieldbus

  • Foundation Fieldbus is a digital protocol designed for process automation that includes features such as distributed control and High-Speed Ethernet compatibility. 
  • It allows for improved functionality and effective collaboration in complex industrial processes.

OPC (OLE for Process Control)

  • OPC is a telecommunications solution that is designed specifically for use in industrial applications. 
  • It is comprised of a number of different standards. The most recent version, OPC UA (Unified Architecture), provides platform-independent data interchange and better interoperability.


  • DeviceNet is a specialized network protocol designed to facilitate communication between simple industrial devices and higher-level devices within industrial automation systems. 
  • Developed to improve efficiency and streamline communication, DeviceNet serves as a robust link connecting sensors, actuators, and control systems. 
  • Its unique capabilities make it a valuable asset in industrial settings where the seamless exchange of data between various devices is crucial for optimizing processes and enhancing overall system performance.


  • CANopen, which is based on the Controller Area Network (CAN), is used for automation in embedded systems. 
  • It provides a wide range of communication services and is appropriate for a wide range of industrial applications.

Industrial Ethernet

  • The usage of standard Ethernet protocols in industrial applications is referred to as industrial Ethernet
  • It optimizes communication in industrial automation with ruggedized connectors and support for real-time control.

AS-Interface (Actuator Sensor Interface)

  • AS-Interface is a simple and low-cost interface for connecting basic field equipment such as actuators and sensors to a control system. 
  • AS-Interface, which operates on a master-slave configuration, facilitates device integration in industrial automation, making it a great solution for applications where ease of use and affordability are critical. 
  • Its ease of use allows for speedy installation and commissioning, which contributes to effective and dependable automation systems.
  • CC-Link, which originated in Asia and is especially popular in Japan, is a versatile protocol that allows communication and data sharing across devices from various manufacturers. 
  • Its extensive popularity can be ascribed to its capacity to establish a continuous communication link between various industrial devices. CC-Link promotes interoperability by allowing equipment from many vendors to be integrated into a uniform and cohesive automation system.

SERCOS (SErial Real-time Communication System)

  • SERCOS stands out as a digital motion control bus, connecting motion controls, drives, I/Os, sensors, and actuators in numerically controlled machines and systems. 
  • Its fundamental strength is in enabling high-speed, real-time communication, which makes it crucial for applications requiring precision and rapid response. 
  • SERCOS is a prominent participant in sectors that rely on dynamic and accurate motion control to achieve operational success.


  • Since 1987, Phoenix Contact’s Interbus serial communication standard has been an established standard in automation technology. 
  • It enables industrial equipment and controllers to communicate reliably.

BACnet (Building Automation and Control Networks)

  • BACnet is a building automation protocol that encompasses HVAC systems, lighting, security, and fire detection. 
  • It allows for the seamless integration and control of many systems within a structure.


  • Echelon Corporation created LonWorks to meet the needs of control applications. 
  • Its dependable LonTalk protocol guarantees reliable networking in a wide range of automation applications.


  • KNX, an open building automation standard, allows for the management of diverse systems such as lighting, HVAC, security, and more. 
  • Its vast use indicates its adaptability and interoperability.


  • WirelessHART addresses the communication problems associated with industrial situations where wire is impractical. 
  • It makes use of HART-based wireless sensor networking technologies.


  • Zigbee is tailored for low-data rate and low-power applications, making it an ideal choice for wireless control and monitoring applications. Its efficiency in conserving power aligns with the demands of IoT (Internet of Things) devices. 
  • Zigbee has not only found success in industrial settings but has also gained popularity in consumer applications, notably in the realm of home automation. 
  • ts ability to create robust and energy-efficient wireless networks positions it as a key player in the expanding landscape of interconnected devices.

MQTT (Message Queuing Telemetry Transport)

  • MQTT, a lightweight messaging protocol, is designed to cater to the unique requirements of IoT devices operating under limited network bandwidth. 
  • Its simplicity and efficiency in transmitting messages make it a preferred choice for a wide range of industrial applications. MQTT’s publish-subscribe model ensures effective communication, allowing devices to exchange information seamlessly. 
  • This protocol has become integral to the fabric of the IoT ecosystem, supporting real-time communication in diverse industrial scenarios.

IEC 60870-5-104

  • IEC 60870-5-104 plays a pivotal role in telecontrol functions within electrical engineering and power system automation. This standard ensures secure and reliable communication in critical applications where remote control is essential. 
  • Its application extends to scenarios where the integrity of data transmission is paramount, such as in the management of power grids and electrical systems.

DNP3 (Distributed Network Protocol)

  • DNP3 stands as a robust standard for communication with data acquisition and control equipment, particularly prevalent in utilities like electric and water companies. 
  • Its reliability and resilience make it a cornerstone in critical infrastructure, where accurate and timely data exchange is imperative for efficient operations. DNP3 is integral to the functioning of utility systems, ensuring the continuous flow of essential services.

IEC 61850

  • IEC 61850 is a standard specifically crafted for the design of electrical substation automation. By defining communication protocols, it plays a crucial role in ensuring the reliability and efficiency of power systems.
  • IEC 61850 facilitates seamless integration and communication between various components within electrical substations, contributing to the overall stability and performance of power distribution networks.

M-Bus (Meter-Bus)

  • M-Bus, a European standard, is instrumental in the remote reading of water and energy meters. It streamlines data collection and management in utility applications, enhancing the efficiency of metering processes.
  • M-Bus enables utilities to gather accurate consumption data remotely, reducing the need for manual interventions and improving overall operational efficiency.

P-Net (Process-NET)

  • P-Net is employed in industrial applications to facilitate real-time distributed control. This protocol enhances the efficiency and responsiveness of process control systems, ensuring that critical industrial processes operate seamlessly. 
  • P-Net’s ability to provide real-time control contributes to the optimization of manufacturing and production processes

EtherCAT (Ethernet for Control Automation Technology)

  • EtherCAT is a high-performance open Ethernet-based fieldbus solution that optimizes process control applications and automation technology.
  • Its speed and efficiency make it popular in companies that require real-time communication and precise control. EtherCAT has become an essential component of high-performance automation systems, providing a dependable and rapid communication solid foundation.


  • RS-232, a long-established serial communication standard, continues to define signals for data transmission between devices. Its utility in a variety of industrial applications remains, as it provides a dependable communication interface for a wide range of equipment. 
  • The simplicity and effectiveness of RS-232 make it a reliable choice in settings where serial communication is still required.


  • RS-485, which defines electrical characteristics for serial communications, is used in building automation, industrial settings, and transportation. 
  • Its toughness and capacity to function in harsh circumstances make it ideal for scenarios requiring reliable and flexible communication. RS-485 is a reliable solution for a wide range of industrial applications.


  • Bluetooth, a wireless technology standard, enables data exchange across short distances between fixed and mobile devices. 
  • Bluetooth Low Energy (BLE) is frequently used in industrial applications because to its robust and energy-efficient capabilities. Bluetooth’s adaptability and broad compatibility make it an ideal alternative for a variety of industrial settings where wireless communication is required.


  • Wi-Fi, which is based on the IEEE 802.11 standard family, is widely used for local area networking and Internet access. 
  • Its versatility and widespread adoption make it suited for a wide range of industrial applications, particularly those requiring high-speed data transfer and networking over long distances. 
  • Wi-Fi has become an essential component of the connection fabric in modern industrial environments, supporting a wide range of applications and enabling smooth device communication.

Sundareswaran Iyalunaidu

With over 24 years of dedicated experience, I am a seasoned professional specializing in the commissioning, maintenance, and installation of Electrical, Instrumentation and Control systems. My expertise extends across a spectrum of industries, including Power stations, Oil and Gas, Aluminium, Utilities, Steel and Continuous process industries. Tweet me @sundareshinfohe

Related Articles

Back to top button