Characteristics and Development Trend of Industrial Ethernet

Industrial Ethernet has gradually developed into the standard communication technology of global industrial control automation, with the advantages of higher efficiency, more functions and higher adaptability, so that enterprise data communication adopts a unified way. Let's take a closer look at the characteristics and development trends of Industrial Ethernet.

Characteristics and Development Trend of Industrial Ethernet

At present, the most important use of industrial Ethernet is in the management layer and the control layer. And through special real-time Ethernet technology, in motion control applications, it can meet the application requirements of response time less than 1ms. For example, CIPsync, ProfiNetIRT and ETHERNETPowerlink have implemented such applications, so the real-time problem can be considered solved. The situation of safety issues is similar, the basic issue is a proper safety protocol based on Ethernet transmission, such as Profisafe based on Profinet, CIPSafety based on EtherNet/IP are all about to be put into practical use.

1. Explosion-proof protection of industrial Ethernet network

Industrial Ethernet has been widely used in industrial automation, and in the field of process control, the problem to be solved urgently is explosion protection. There are already switches that support Ex-Zone2. However, implementing the requirements of Ex-Zone1 is the key to getting Ethernet deep into the field layer. Expensive cabinets are no longer favored by users.

What users need is a so-called intrinsically safe switch. While ensuring the high speed of Ethernet, the inherent safety feature is the challenge of this technology. Perhaps, it will take some time before the first intrinsically safe switches connected by twisted pairs are available. However, once this technology is realized, Industrial Ethernet will play an even more pivotal role in process automation.

2. Future network topology

In a bus system, users are used to daisy-chain connection of field devices. As a result, automation manufacturers now produce Ethernet devices that are compatible with daisy-chaining, or, in other words, install 2 switch ports on field devices. However, the switching cost increases as the number of devices increases compared to the use of a stand-alone Industrial Ethernet switch. Another disadvantage is that the throughput and bandwidth of daisy-chained switches can be limited when traffic bursts because all users have to communicate over a common cable. The important advantage of the ring connection is that on the one hand, it reduces the wiring cost, and on the other hand, it can improve the reliability of the link. For example, when one place does not work properly, the communication is not affected. Therefore, it is necessary to decide which method is suitable according to the application and requirements.

3. Let the switch learn automation language

Large automation manufacturers use their own Ethernet-based application protocols, similar to EtherNet/IP, Profinet or Modbus/TCP. These protocols all support standard TCP/IP, so standard industrial Ethernet switches can also be used in such applications. The SNMP protocol has been widely used in commercial environments for switch configuration and diagnostics. However, the configuration tools used in automation do not support the SNMP protocol, making it difficult to configure the appropriate switches. So Hirschmann started to let the switch learn the language of automation, and it will be possible to configure the switch using PLC, drive device or I/O in the future. The greatest benefit to the user is that the network can be configured with familiar automation tools, and a complete bill of materials can be easily created.

4. The Importance of Safe Growth

Since industrial Ethernet can achieve consistent data transmission from management level to field level, users only need to master one network technology, and at the same time, work efficiency is also improved.

However, a unified network structure also bears certain risks due to overall network transparency. For example: the IP address of the robot in the production line can be operated by any workstation. Therefore, there must be a set of clear rules to define the time and object of communication. Of course, it is not enough to just install a firewall at the company's egress to resist external attacks. A fatal error or even downtime is often caused by internal misoperations, so the distributed security system is very critical in the field of automation. Because of this, the entire system or system components can be divided into independent security units, and each security unit communicates through defined rules.

5. Wireless networks provide new application possibilities

Nowadays, wireless network technology (WirelessLAN(WirelessLocalAreaNetworks)) is widely used in office environment. The advantages of mobility, flexibility, very easy installation, low cost, and wireless communication make this technology increasingly used in industrial environments. WLANs are now increasingly becoming a supplement to traditional wired networks. Typical applications are on mobile terminals in production logistics, operating and monitoring production lines or providing fast exchange of online data. For example, reservation data can be sent directly from the monitoring center to the forklift in the warehouse.

Now there are many industrial-grade WLAN devices on the market, all of which are based on the IEEE802.11b/g/a/h protocol and can provide a data transmission speed of about 100Mbit/s. In terms of transmission distance, if a suitable antenna is used at the 5GHz frequency, it can reach 20 kilometers. Hirschmann's wireless network solutions can meet such needs. In the future, the extended protocol IEEE802.11n will further standardize the standard of WLAN in the industrial environment. The new standard is likely to be implemented next year, when data communication will be more reliable and faster, up to 640Mbit/s, even in environments with poor radio communication conditions.

Radio networks in industrial environments are also differentiated according to the application of WLAN. For example, WiMAX (IEEE802.16) for data transmission over a distance of 70 kilometers or Bluetooth (IEEE802.15.1) and Zigbee (IEEE802.15.4) for short-range transmission. Zigbee is very interesting, because of its low power consumption, it is very suitable for wireless communication between sensors. However, widespread adoption of this technology in an industrial setting may be several years away.

6. The trend of higher network bandwidth

Both wired and wireless networks require higher and higher network bandwidth. In industrial environments, especially at the control level, Fast Ethernet (100Mbit/s) is almost defaulted to today's mainstream. However, there is an increasing trend towards GigabitEthernet in both automation and office environments. The reasons can be attributed to the following three points:

First, as more and more field devices are connected via Ethernet, bandwidth requirements increase as the number of devices increases.

Second, multiple services, such as control data, IP telephony or IP video, are also growing rapidly and are transmitted over the same cable.

Third, Gigabit Ethernet has ten times the switching capacity of Fast Ethernet, and many real-time applications can be implemented in a standard Gigabit Ethernet environment.

As with wireless solutions, higher transmission speeds mean higher power consumption and higher-cost chips. However, as the cost of chips has fallen, Gigabit Ethernet has become increasingly common in industrial settings