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Connected Machines One Communication Protocol for All Machines
Today, machines communicate in many languages. A fact that makes networking more difficult. The standard OPC UA, which is increasingly supported by more and more vendors, is supposed to change this.
It all began with the construction of the Tower of Babel: when God saw that people were trying to match him with this gigantic project, he punished the builders by giving each of them his own language and no one could understand the other anymore. Due to this Babylonian language confusion, the construction of the tower remained unfinished. Nowadays, linguists count about 7,000 languages in the world — dialects not included.
Industrial automation processes are also rich in languages, where machines use communication protocols to exchange control commands or data with each other. These protocols are often linked to specific manufacturers and machines do not understand each other. The disadvantages of this diversity are obvious: While end customers are often caught up in proprietary systems, manufacturers of sensors, controllers or other components have to develop multiple versions of the same products in order to support the different protocols.
VDMA in Favor of OPC UA
Poor conditions for the Industrial Internet of Things: "The aim of IIoT is to network the individual machines involved in the production process, not only the product itself, as well as the employees and customers. The prerequisite for this is that all components fit together," said Dr. Burkhard Raith, Chairman of the VDMA Technical Policy Steering Committee, in the run-up to SPS IPC Drives 2017, "Only coherent standards and norms can create the prerequisites for components, machines and entire systems to communicate with each other reliably".
The VDMA favors the open interface standard OPC UA to achieve connectivity. This abbreviation stands for Open Platform Communications Unified Architecture. The manufacturer-independent communication protocol for industrial automation applications enables integrated communication from individual sensors and actuators to the ERP system or into the cloud. This protocol is platform-independent and has built-in security mechanisms.
Standard for the IoT
However, OPC UA has hitherto reached its limits in complex processes with real-time requirements. The relevant committees want to eliminate this deficiency: To this end, OPC UA will be extended to include a Publish/Subscribe model and will in future be based on the Time-Sensitive Network Standard (IEEE 802.1). The resulting OPC UA TSN protocol will become the standard for communication in the Industrial Internet of Things (IIoT) up to the control level.
At this year's SPS IPC Drives trade fair in Nuremberg, leading companies recommended the use of OPC UA TSN at a joint press conference. ABB, Bosch Rexroth, B&R, Cisco, General Electric, Kuka, National Instruments, Parker Hannifin, Pilz, Schneider Electric, SEW-Eurodrive and TTTech want to support the protocol in future product generations.
Tests Passed Successfully
According to the companies, tests carried out by B&R and TSN network specialist TTTech have already shown that time-critical applications at line level, such as synchronizing conveyor belts with different machine or plant components, can be realized with OPC UA TSN.
Thomas Pilz, managing partner of automation specialist Pilz GmbH & Co from Ostfildern near Stuttgart, Germany, places high expectations on the protocol: "Thanks to OPC UA TSN, manufacturers will be able to compete on the functionality of their products in the future, while ensuring communication between the products" Thomas Pilz admits, however, that he is anticipating a "transition period of ten years until interoperability works".
This article was first published by Konstruktionspraxis.