Factory components from the lowest level to the highest level
As the volume of data produced increases, compatibility and connectivity become important
TSN-based OPC-UA, Key to Industry 4.0 Implementation


Factory automation collects data individually as automation and optimization are carried out on a unit-by-unit basis. In contrast, smart factories can collect data integrally, allowing for data linkage. To link the data collected by countless processes and equipment within a factory, it is facilitated by utilizing a supplier-independent factory automation application communication protocol called 'OPC-UA (Open Platform Communications Unified Architecture).'

Flexible and completely independent OPC-UA bridges the gap between the IP-based world of the factory's IT domain and the production site. All production process data is transmitted within the equipment, between equipment, or between equipment and a cloud database using a single protocol.

As the size of data and the number of equipment being produced increase, a Time Sensitive Networking (TSN) standard that is at least 10 times faster than existing industrial Ethernet standards is required to maximize the potential of the OPC-UA protocol.

◇ OPC-UA, an open protocol suitable for smart factory implementation

OPC-UA originated from OPC (OLE for Process Control). As industry demand for smart factories grew, the OPC Foundation changed the definition of OPC to 'Open Platform Communication'. Currently, almost all factory automation equipment suppliers, including Siemens, Rockwell, and Mitsubishi, supply products with the OPC-UA protocol built-in.

Smart factory engineers in the industry are grappling with how to integrate existing industrial fieldbus standards with the OPC-UA protocol. While this can be resolved by developing additional features internally, it creates a problem of incompatibility with products from other companies. Accordingly, the OPC-UA Foundation provides 32 information models.

This model includes industry-standards along with guidelines on how to handle events generated by each component when utilizing OPC-UA. As an open protocol, OPC-UA can be used on any enterprise's equipment and operating system (OS). In other words, it is an ideal protocol for enhancing smart factory connectivity.

◇ TSN, a next-generation standard that enhances the industrial applicability of Ethernet

Currently, industrial Ethernet operates at a speed of 100 Mbps. As the amount of data to be processed increases due to the advancement of automation facilities and the high performance of equipment, the need for Gigabit Ethernet standards has arisen, leading to the emergence of the TSN standard, a next-generation industrial Ethernet standard.

A characteristic of the TSN standard is that it possesses both real-time capability and time determinism simultaneously.

Real-time refers to the real-time connection between devices within the same network. While there may be some delay when viewed in clock units, the devices perceive this as real-time. In the field of automation, real-time refers to how often and at what frequency robot controllers, motion controllers, PLCs, and other devices communicate.

In the field of automation, time determinism refers to the ability of components to process real-time communication within a defined timeframe. High-performance communication is only possible when it operates consistently at specific intervals. This serves as a critical factor in high-speed I/O processing and synchronous control.

TSN is a standard that is continuously being refined. Automation companies are striving to convey industry opinions to the IEEE by establishing the 'IIC (Industrial Internet Consortium) TSN Interoperability Testbed.' Network switches are a representative TSN-related product. This is because it has become important to properly connect network systems that are growing massive due to gigabit speeds. Companies participating in the IIC are manufacturing numerous network switches.

If TSN is a highway, OPC-UA defines the specific types of vehicles that can operate on it. Although the OPC-UA protocol is currently used in 100Mbps Ethernet, the demand for data processing in smart factories continues to increase. This means that the number of components that can be connected to the network system is increasing.

Connecting sensors at the lowest level to equipment at the highest level via a neural network (NN) is a fundamental requirement for smart factories. Without an NN, gateways or middleware are required to connect them. This slows down speeds and hinders determinism, thereby increasing production costs. Therefore, the TSN standard is an essential network technology for systems such as Cyber Physical Systems (CPS).