Complementing the pros and cons of existing fieldbus and general Ethernet, strengths in speed and redundancy
Wireless communication is increasingly being introduced for monitoring purposes based on 802.11 technology.

As smart factories become an issue due to innovation in manufacturing, interest in industrial network technology is also increasing.

In terms of industrial network technology, industrial Ethernet is rapidly expanding in wired communications, and in the wireless communications field, it is mainly used for monitoring purposes rather than control purposes based on 802.11 technology.

First of all, industrial wired communication is spreading industrial Ethernet technology that takes into account the strengths of existing fieldbus and general Ethernet. Fieldbus is an industrial communication technology that is widely used because it is excellent in wiring convenience and small data processing capability, and above all, it is a proven technology with price competitiveness. However, it had the disadvantages of lacking communication media and compatibility, not being able to respond to increasing application demands, and above all, having limited speed (12-16 Mbps) and poor implementation of redundancy functions.


▲Siemens industrial Ethernet switch

In contrast, Ethernet has the advantage of being a mainstream technology that is familiar to the general public, with high-speed transmission speeds (10M to 10Gbps), communication media compatibility, but has the disadvantages of having a vulnerable topology, being non-deterministic, and requiring external switches and hubs.

“Fieldbuses have been used for a long time in industrial networks because they only needed to process small amounts of data, but now that video data is increasing in factories, transmission speeds need to be faster,” said Kwon Dae-hyun, a senior researcher at LS Industrial Systems. “General Ethernet also has problems. It is price competitive, but if one switch breaks down, the entire system can have problems.”

Industrial Ethernet Market Continues to Grow at 20% Annually

Accordingly, industrial Ethernet, which has the advantages of these wired communication standards, is the trend. Industrial Ethernet has supplemented topology vulnerabilities with linear/ring/mesh structure topologies as well as communication media compatibility with high-speed transmission speeds. In particular, it complements its shortcomings with powerful redundancy functions, real-time communication at the 1ms level, and time synchronization at the 1us level.

The industrial Ethernet market is growing at a rate of 20% per year and is integrating existing networks into Ethernet. If this is expressed in numbers, the market size of about 4 trillion won in 2013 is expected to form a 7 trillion won market in 2016 and exceed 10 trillion won in 2018. In terms of technology, the real-time performance of Ethernet is increasing and the commonization of cables and connectors is leading the integration of existing 3-level networks into one. Furthermore, it is expected that its influence will be maximized in the future as it can be applied to tens of millions of devices.

▲ Comparison of industrial wireless communication standards

Accordingly, it is expanding from the existing serial communication base to the industrial Ethernet base. The basic Ethernet technology that is convenient for development and considers compatibility is also moving to technology that considers performance, redundancy, and safety. In contrast, the EtherCAT technology that was growing rapidly is limited to the motion field and its importance is slightly decreasing.

It is also noteworthy that Siemens is expanding its territory by utilizing Profinet technology, and Mitsubishi's CC-Link is strong in Asia. These companies are expanding industrial control networks to include lower-level device communications. Siemens is expanding its overall measurement through Profinet, and Mitsubishi is promoting a unified network for control and device measurement with Ethernet-based CC-Link IE. Domestic LS Industrial Systems is expanding its RAPIEnet expansion strategy by securing various communication modules. American company Rockwell standardized the upper layer with EtherNet/IP and the lower with DeviceNet, and expanded its Ethernet solution to the device area.

Industrial wireless communication is centered on Wi-Fi technology and 802.15.4-based technology.

The remarkable growth of industrial wireless communication is also noteworthy. Wireless communication can be classified by system. Cross Plant Wireless Network is a wireless network for remote maintenance and control, and Plant Wide is a wireless network for various plant applications. Sensor/Actuator Wireless Network monitors sensor actuator nodes operating at the field level through gateways. The industrial wireless network market is expanding centered on Emerson, GE, and Honeywell, and is being developed mainly based on individual standards and WirelessHART/ISA 100.11a.

The need for industrial wireless communications is centered around six use cases: ▲ worker safety around operating equipment ▲ level monitoring and alarms in oil tank assembly areas ▲ field worker support with mobile wireless equipment ▲ vibration monitoring and analysis of rotating equipment ▲ oil well monitoring and control ▲ several applications for factory automation with many nodes.

In the wireless communications field, there are Wi-Fi technologies based on 802.11 and technologies based on 802.15.4. IEC is reviewing the bandwidth (80MHz) and frequency (1.4GHz~6GHz) considering the industrial environment. Looking at the application technologies of specialized companies such as Siemens, Rockwell, Mitsubishi, and Schneider, WLAN and Bluetooth account for a significant proportion. These wireless technologies were mainly used for monitoring purposes rather than control purposes.

“What makes industrial communications different from general communications is that it requires real-time communication and deterministic recovery times in the event of an error,” said Kwon Dae-hyun, head of LS Industrial Systems. “High availability, functional safety, and security are also important considerations when applied to the industrial sector.”