An Overview of Industrial Communication Protocols

Industrial communications protocols are sets of rules that govern how devices and applications exchange data and information. They define the syntax, procedures, and error handling rules for data exchange, similar to how programming languages are used in software engineering.

In manufacturing environments, industrial communications protocols dictate which devices can integrate with which applications, and vice versa. Common OT to OT integrations include devices to HMIs, devices to SCADA systems, devices to MES applications, and in the era of industry 4.0 and smart manufacturing, there are an increasing number of OT to IT integrations, for IoT, analytics, BI, and AI.

These integrations and use cases enable manufacturers to improve visibility, enable data-driven decisions, and automate processes. In this blog, we will discuss the top 10 industrial automation protocols, their functionality, and why they are pivotal for modern manufacturing operations.

What are industrial communication protocols?

Industrial communication protocols are standardized sets of rules that govern the exchange of data among machines, sensors, programmable logic controllers (PLCs), and other industrial equipment. These protocols ensure that interconnected devices communicate effectively and consistently in industrial networks.
Some of the key messaging patterns used in industrial communication include:

• Request-response pattern: One machine requests data or commands and the other machine responds, as it is widely deployed in point-to-point communication
• Publish-subscribe pattern: Devices or systems publish data to each other or to an intermediate broker, and subscribers who have expressed interest in specific data sets begin to receive data as it's published

Let’s break down the most widely used protocols in industrial automation.

What are the top 10 industrial communication protocols?

1. MTConnect

• Overview: MTConnect is an open, royalty-free protocol that standardizes the communication vocabulary for machine tools and manufacturing devices, ensuring interoperability
• Key uses: Found in manufacturing environments needing real-time production monitoring and analytics
• Strength: Provides consistent terminology between machines and software for manufacturing operations

Kepware’s MTConnect Driver

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2. Open Platform Communications Unified Architecture (OPC UA)

• Overview: OPC UA is a highly versatile secure, cross-platform communications specification for industrial automation and IoT
• Key uses: Industrial automation systems and IoT-enabled devices requiring secure data exchange between diverse equipment, manufacturing systems, and IT systems
• Strength: Interoperable across operating systems such as Windows, Linux, and custom embedded architectures

Kepware’s OPC Connectivity Suite

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3. Ethernet/IP

• Overview: This protocol employs standard Ethernet technology, integrating with the Common Industrial Protocol (CIP)
• Key uses: Facilitates high-speed, real-time communication for motion control, I/O, and device-to-device and device-to-host communication
• Strength: Its foundation on Ethernet and deep feature set offers robust scalability and flexibility for a variety of uses across automation settings, including machine-to-machine and integrations into IT systems

4. FANUC FOCAS

• Overview: A proprietary protocol developed by FANUC for computer numerical control (CNC) data exchange
• Key uses: Widely used in CNC operations to monitor or control FANUC devices with third-party systems
• Strength: Recommended for factories with FANUC machinery for enhanced productivity insights

5. Modbus

• Overview: Originally developed in 1979 for communication with PLCs, Modbus remains a simple, performant, and widely supported protocol
• Key uses:
  • Modbus RTU: Communication over serial connections like RS-485
  • Modbus RTU over Ethernet: Serial-style Modbus RTU packaged in TCP/IP or UDP/IP
  • Modbus TCP/IP: Native Modbus communications over Ethernet networks
• Strength: Open and vendor-neutral, ensuring wide compatibility

Kepware’s Modbus Suite

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6. Building automation and control network (BACnet)

• Overview: BACnet is widely adopted for building management systems (BMS), facilitating control over HVAC, lighting, fire detection, and access control systems
• Key Uses: Especially prevalent in automation for smart buildings
• Strength: Open standard supporting cross-vendor integration

Kepware’s BACnet/IP Driver

Connect to building automation devices with the BACnet/IP driver from Kepware.

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7. LSV/2

• Overview: Used for communication with CNC machines, particularly favored in Europe for precise control functions
• Key uses: Industrial machining environments with CNC systems requiring sophisticated data handling
• Strength: Offers high command granularity for specialized CNC applications

8. Transmission Control Protocol/Internet Protocol (TCP/IP)

• Overview: A staple in both industrial and nonindustrial networks, enabling data exchange over Ethernet
• Key uses: Ubiquitous data transfer protocol; typically leveraged any Ethernet-based communications network from legacy industrial systems to modern IIoT ecosystems
• Strength: Universally adopted with robust compatibility across software and hardware, usually as part of basic Ethernet feature set

9. IO-Link

• Overview: A point-to-point protocol that integrates sensors and actuators with automation systems, enhancing diagnostics and simplifying configurations
• Key uses: Frequently employed to retrieve sensor diagnostics or adjust settings, improving predictive maintenance tasks
• Strength: Supports rapid device parameterization, while delivering detailed diagnostics

10. Universal machine technology interface (UMATI)

• Overview: UMATI is a global initiative for open communication interfaces, where machine-building industries and their customers can leverage OPC UA as its foundation in a standards-based approach, allowing for broad compatibility across different manufacturers and platforms
• Key uses: Standardizes integration with machinery as part of manufacturing, IT, and Industry 4.0 ecosystems
• Strength: Promotes modularity and vendor agnosticism in machine tool communication

What is the most commonly used industrial communication protocol?

Modbus is recognized as the most widely implemented protocol, owing to its time in the market, wide vendor support, simplicity, performance, and openness. With options like Modbus RTU for legacy systems and Modbus TCP/IP for modern networks, it supports seamless integration with diverse industrial systems.

What are the different industrial communication protocols?

Here’s a compiled list of protocols catering to specific applications:

• Widely used protocols: Modbus, Ethernet/IP, PROFINET, PROFIBUS, OPC UA, BACnet
• Emerging protocols: Message Queuing Telemetry Transport (MQTT) and UMATI
• Legacy systems protocols: RS-232, RS-485, CAN bus

Key Takeaways and Next Steps
Industrial communication protocols form the backbone of enterprise connectivity in increasingly digitalized ecosystems. Leveraging these systems ensures operational efficiency and makes predictive maintenance, real-time tracking, and enhanced interoperability achievable.

To explore how industrial communication protocols can be tailored to your operations, visit Kepware and learn about solutions providing reliable, standardized, and secure industrial connectivity.

Kepware driver library

For more information about industrial protocols, explore the Kepware Device Driver library.

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