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world of industries 3/2017 (EN)

world of industries 3/2017 (EN)

in cooperation with

in cooperation with Fluidtechnik Antriebstechnik in cooperation with in cooperation with in cooperation with Fluidtechnik Antriebstechnik REACH INTERNATIONAL DECISION MAKERS! BRASIL CHINA GERMANY INDIA INDONESIA ITALY RUSSIA TURKEY USA Selection of the DLC control platform During the towing operation, DLC is the heart of the towing tractor. Therefore selecting the right DLC is extremely crucial. For the selection of the drive control, focus was mainly on a flexible and high power control unit which would be in a position to reliably execute the functionalities related to safety. The control unit should be adaptable to other types of aircraft tractors and provide the required performance to safely cover the current and future requirements. The 32-bit control unit ESX-3XL Safety from the company Sensor-Technik Wiedemann (STW) seems like a perfect solution that caters to all the requirements. The ESX-3XL is certified according to the DIN IEC 61508: SIL 2 and DIN EN ISO 13849: PL d standards (Fig. 2). The control unit is based on a 32-bit Tri-Core controller with a 150 MHz core, 4 MB RAM, 6 MB Flash and 32 kB EEPROM. In addition to the flexible adaptation possibilities in the basic version – e.g. all inputs can be configured via the functions in it as current/ voltage/digital or rpm inputs – the possibility to extend the device via expansion boards represents an outstanding feature of the ESX- 3XL. Because the control unit can be configured with up to six of these boards, it simply provides more flexibility to the operation. At the moment, 14 expansion board versions featuring different inputs and outputs, in addition to RS232 / RS485 / CAN interfaces and a programmable Linux system including Ethernet and USB are available. Generally, development environments for programming in “C”, Matlab and Codesys are available. For the development of the DLC, the development environment Codesys in version Codesys Safety SIL2 was chosen (Fig. 3). DLC: safety functions and standards INTRALOGISTICS & DISTRIBUTION INDUSTRIAL AUTOMATION 01/2017 www.engineering-news.net www.engineering-news.net 01/2017 MOTION, DRIVE & AUTOMATION 01/2017 01/2017 In accordance with the applied standards, a risk analysis for the drive functionalities was carried out, which required several functions to be in a safety level of AgPLr ≥ c. Safety-orientated development represents a substantial cost factor during product development and during maintenance of the subsequent product. Therefore, particular attention was paid during drafting of the technical safety concept to a clear and unambiguous definition of the safety functions and their assignment to the appropriate software components. The focus was placed on keeping safetyrelevant parts as simple as possible and creating clear interfaces between safety-relevant and non-safety-relevant software parts. In the software architecture, this is presented in appropriate safety-relevant and non-safety-relevant modules (Fig.4). The clear assignment of functionalities and the precise definition of the interface between the two software worlds is always meaningful. But it will only lead to cost reductions for development and maintenance if the separation of different software components is supported by the hardware. www.engineering-news.net www.engineering-news.net www.world-of-industries.de About Sensor-Technik Wiedemann GmbH (STW) The company Sensor Technik Wiedemann, based in Kaufbeuren Germany, develops a wide range of products in measurement technology, control and automation systems, telematics and machine connectivity. The company also offers services in system design, implementation support and software solutions for communication and control functionality. STW caters to companies that are manufacturers of mobile machines and industrial vehicles both on and off-road. The company has subsidiaries in UK and USA, and employs more than 440 people. Please find media informations here: www.vereinigte-fachverlage.info

MACHINE ELEMENTS IEC 61508-3, 7.4.2.9 defines that software parts with different safety classifications are to be developed on a control unit in accordance with the highest safety level, unless they are suitably independent through temporal and spatial separations. The ESX-3XL control unit supports temporal and spatial independence of application parts by providing appropriate memory protection and watchdog functionalities. With the supplied safety mechanisms software with different safety requirements can be independently executed on the ESX-3XL. This opens up the possibility for the development team to develop non-safety-relevant parts of the application in accordance with a simplified development and verification process. Optimum DLC parameterization reduces costs and complexity The objective was to guarantee a standard compliant parameterization of the DLC. In addition, it was necessary to verify that parameter changes to non-safety-relevant application parts would not have any effects on the safety relevant application parts, in order to keep the required validation and verification expenses as low as possible here, too. Basically, every additional parameterization provides additional complexity, additional error sources and therefore increased validation and verification expenses. Accordingly, attention was paid in the specifications and design of the safety relevant modules to limit the number of parameters to a minimum. The process of safe parameterization is supported via the ‘ESX-Kefex’ toolchain. This Toolchain is part of the ESX-3XL development environment and comes with a detailed user and safety manual. The ‘ESX-Kefex’ toolchain has been certified for use in projects with safety requirements in accordance with DIN IEC 61508: SIL 2 and DIN EN ISO 13849: PL d. Disconnection of safety-relevant / non-safety-relevant components The entire development process including risk analysis, hardware assignment, preparation of safety concept, software architecture, implementation and verification has been realized in close coordination between STW and Goldhofer, which has resulted in a safe, maintainable and optimally tuned drive system. Photographs: Lead Photo Goldhofer AG, 01-03 STW GmbH www.sensor-technik.de/en Power Transmission Engineering Fluid Power New Edition: VDMA Directory 2017 Power Transmission Engineering and Fluid Power „Motion, Drive & Automation“ • Economic/Technical Situation of German Manufacturers • List of German Suppliers • Company Profiles HANNOVER MESSE 24. – 28.04.2017, Hanover Pick up your free copy at the VDMA booth in hall 19/A52 or contact us: fluid@vdma.org