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Automation Technologies 2/2014

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Automation Technologies 2/2014

Components and software

Components and software back to current issue Author: Xaver Schmidt, Industrial Automation Systems, Siemens AG, Nuremberg, Germany PROFIsafe and Profinet for more efficiency in safe plants and machines Xaver Schmidt A new era in the automation of safety-related machines and plants began 15 years ago with the first PROFIsafe specification in 1999. The continuous development of PROFIsafe in this new era not only guarantees greater safety, but also maximum functionality. 118 AUTOMATION TECHNOLOGIES 2/2014

Components and software next page Even today, users and manufacturers alike are impressed by the simplicity and safety of the PRO- FIsafe solution. This is based on the “black channel” principle that was first used with PROFIsafe as the foundation of a communication-based solution for functional safety. In order to reduce the costs for equipment, engineering and the operation of safetyrelated plants and machines, safety and standard data are routed together on the same communication medium. This permits a much more efficient implementation of extremely effective safety reactions. One essential requirement was the reactionless integration. The core of the principle is that safety-related information is packed into a secure “PROFIsafe container”. In the case of an emergency stop, for example, the signal status of the safety sensor or of the emergencyoff pushbutton is transmitted by PROFIsafe telegram to the safety controller, edited and then forwarded to a drive, for example. On arrival of this telegram in the drive unit, the requested safety reaction is triggered, for example the drive is switched to torque-free operation using the “Safe Torque Off” (STO) safety function. In parallel with the safety-related traffic of the PRO- FIsafe telegrams, standard data is also exchanged over the same medium with the drive unit in question and the other devices; meanwhile the communication continues in the network. Without PROFIsafe this would require additional cabling and the interconnection of relays. With PRO- FIsafe, everything runs on one cable so that standard and safety data can be processed together in one F-CPU. The drive manufacturers, who established an international standard (IEC 61800-5) for failsafe drives, became the promoters of the PROFIsafe technology. Manufacturers of electrical drives have integrated safety functions into their products, such as “Safe Torque Off”, which has now become the standard in electrical drives. Thanks to the high profile of the PI Organization (Profibus & Profinet International) and of the member companies, PROFIsafe was quickly able to establish itself in the market and become the clear market leader. Both the number of device manufacturers and — far more importantly — the number of applications using PROFIsafe is outstanding in comparison with other safety communication solutions. Last year alone, a growth of 50 % was recorded, showing that even at this high level, further growth is possible. Meanwhile, the black channel principle is now included as a state-of-the-art feature in the IEC standards. After all, the use of safety is not a “voluntary” matter, but a subject of statutory regulation. Many standards and guidelines, such as the Machinery Directive 2006/42/EC of the European Union, the Seveso Directive, standards such as IEC 62061 and ISO 13849 (for production automation) and IEC 61511 (for process automation), as well as other local regulations such as NFPA 79 (USA), must be observed. PROFIsafe meets all the requirements of these safety standards. Continuous development Building on many years of experience with Profibusbased PROFIsafe applications, it was possible in 2005 01 The “black channel” permits the transfer of safety data on standard communication media AUTOMATION TECHNOLOGIES 2/2014