Beckhoff: System-integrated overcurrent protection with EtherCAT
Request Further Info   Print this Page   Send to a Friend  

Applied protocols: EtherCAT case study

SWISS COMPANY Ferag AG, located in Hinwil near Zurich, specialises in the conveying and handling of newspapers after the initial printing process. The company has developed production modules with high-tech controllers for NZZ Print, the print shop for Neue Zürcher Zeitung , equipped with Beckhoff CX1020 embedded PCs, the TwinCAT software PLC and EtherCAT.

The finished newpaper comes folded and cut out from the printing press line. Depending on the size of the issue, special newspaper sections and supplements must be laid automatically inside the main newspaper. After the inserts have been added, the address of the recipient is printed on the newspapers and on the accompanying tickets for the newspaper parcels. Finally, the dispatch units are created by wrapping them with a plastic film. Tracking the newspapers through the entire production process is an essential part of the application.

NZZ Print uses virtually the entire range of processing modules offered by Ferag. The linking conveyor equipment is a most spectacular sight: as if on a string of beads, the newspaper sections are conveyed on the typical Ferag yellow clips at breakneck speed in all directions through the plant horizontally, vertically, crossing the room without errors.
The reliability of the plant components is mandatory in the application. This concerns, for example, the machine operation, flexibility in adapting production conditions, interaction in the form of visualisation, display of process status and the like.
Four lines lead from the new Rotation, as the print line in Zurich is called, to the Finishing department. Two of them are main lines, which integrate the insertion area and lead to the packaging area. The two remaining lines are implemented as so-called auxiliary lines. The redundant plant concept covers capacity requirements and, over and above that, serves for production safety. The possible capacity depends on the scope of production, but it can be up to 80,000 copies per hour.

On the control side, the individual workstations are controlled by the Beckhoff CX1020 embedded platform with EtherCAT Terminals, networked via EtherCAT. Embedded PCs are overlaid by a control technology that was developed by Ferag. In deciding in favour of Beckhoff, one important argument was that Ferag already had experience with TwinCAT control software and remove capacity limitations of the previous control system. Many special solutions were previously used with proprietary hardware and local I/O components. In contrast the, EtherCAT solution offers flexible topology and high performance. Specialised modules that were previously implemented in hardware form have now be realised in software.

As the first Ferag modules, the three most important stations were equipped with the CX1020 Embedded PC: the stacker, for packaging; the release controller, which controls the inlet of the newspapers to the stacker; and the MultiSert insertion drum. One special feature of the control solution used at the NZZ is the use of the EtherCAT bridge module, which enables the bidirectional transfer of data from one EtherCAT strand to another. Both strands can also be synchronised via the bridge. An external infeed ensures that the main branch can continue to communicate when the auxiliary branch is switched off.

For example, the release controller handles the exact positioning of the 'released' newspaper in front of the ink-jet labeller and that this process must neither be interrupted nor allowed to get out of control. Reliable release is guaranteed through use of EtherCAT and fast I/O modules the company says.
On account of the high speed involved, the synchronisation of the controllers is also important with respect to the transfer of the newspapers from one transport system to another, which means that we cannot do without cross-communication between the embedded PCs. Synchronisation between communication devices that are far apart is further improved by the use of the distributed clocks function with microsecond accuracy.


Accelerate your HART data at the speed of Ethernet
Industry of Things World

Get Social with us:

© 2010-2020 Published by IEB Media GbR · Last Update: 07.07.2020 · 14 User online · Privacy Policy · Contact Us