Open- and closed-loop control using Ethernet

Ethernet has turned into one of the most important technologies in the area of industrial communications. An ever-increasing number of mechanical equipment and plant manufacturers is using Ethernet and they fare very well with it. According to users, getting into this technology is very easy. Most engineers and technicians are familiar with it from the IT realm.

Taking advantage of this technology


Ethernet is best of all used along with the higher-level protocols and Web technologies. The combination of these technologies offers a number of advantages. Some of them are listed below:

• One integrated networking technology used throughout the whole plant (no discontinuity between systems)
• Each device connected to the network is able to freely communicate with any other device (transparent communications)
• Easy servicing thanks to browser-based visualization. Each device is able to send SMS messages and e-mails. (Preventive maintenance is also possible)
• Very simple connection to the office IT network of production plants (integration into the corporate IT network)

These features of Ethernet and Web technologies offer up possibilities which could not be implemented so far; and if they could, they involved significant effort and expenses.

Solutions for automation tasks using Ethernet

The advantages of Ethernet can be exploited to the full extent if all required devices are equipped with an Ethernet interface. The JetWeb technology offers an integrated solution comprising of controllers, drive control systems, remote I/O devices, HMIs, and industrial PCs. For all these devices, Modbus-TCP can be used as protocol.

Entry-level solutions can be implemented using controllers of the JetControl 24x family. All devices of this family have a modular design. Expansion modules allow remote arrangement through the serial system bus which is transparent with regard to programming and commissioning. Besides a Fast-Ethernet interface, these devices feature an FTP server which can hold programs, as well as additional data. Furthermore, they can hold HTML pages and send e-mails or SMS messages. As to Ethernet and Web functions, the JetControl 647 control system offers the same features, but it is provided with an increased CPU performance and a better expandability.

Real-time Ethernet for motion systems

A distributed automation solution is complete only if it comprises the required drives. Therefore, Jetter AG offers a range of servo controllers communicating with all other devices via Ethernet. The servo controllers of the JetMove 200 family are equipped with a controller, an FTP, as well as an http server, and they make it possible to control brushless drives of the 0.1 to 35 Nm range. The available motor power ranges from 0.4 to 8.5 kW. These servo controllers are logically integrated into the control systems.

The performance of Ethernet is more than sufficient for synchronizing motion systems while using internet protocols.

JetSync is part of the JetWeb technology and makes use of genuine and open Ethernet TCP/IP for drive synchronization:

• During synchronization run, open access to all Web servers located in the drives
• TCP/IP communication with no limitations
• Jitter < 5 – 10 µsec with no special hardware required (ASICs, switches, etc.)
• Download of motion profiles and parameters during synchronization run
• Plug&Work functionality
• Synchronized event handling within 1 ms (e.g. stopping in case of an error)

Remote I/O modules and HMIs make the product range complete

The peripheral system JX-SIO and the Web terminal JetView 301 complete the control technology JetWeb which is fully Ethernet-based. The remote I/O system JX-SIO features various terminals for digital and analog signals. With its Web visualization, the Web terminal JetView 301 is equipped with all the functions required for plant-wide monitoring. The way for using Ethernet in automation has now been paved.

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