2 Ethernet – Fundamentals and Protocols
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Pigan / Metter Automating with PROFINET Automating with PROFINET Industrial Communication based on Industrial Ethernet by Raimond Pigan and Mark Metter 2nd revised and extended edition, 2008 Publicis Publishing Bibliographic information published by the Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available in the Internet at http://dnb.d-nb.de. SIMATIC, S7-300, S7-400, ET 200S, STEP 7, Safety Integrated, SIMATIC NET, SCALANCE are registered trademarks of Siemens AG. If trademarks, commercial names, technical solutions or similar are not specifically mentioned, this does not mean that they are not protected. To improve readability, trademarks and the international designations PROFINET, PROFINET IO, PROFINET CBA, PROFIBUS DP, PROFIBUS DPV1, SCADA, SCALANCE, SINEMA are written in conventional notation (uppercase and lowercase letters). The authors, translator and publisher have taken great care with all texts and illustrations in this book. Nevertheless, errors can never be completely avoided. The publisher, author and translator accept no liability, regardless of legal basis. Designations used in this book may be trademarks whose use by third parties for their own purposes could violate the rights of the owners. www.publicis.de/books Print ISBN 978-3-89578-294-7 ePDF ISBN 978-3-89578-950-2 2nd edition, 2008 Editor: Siemens Aktiengesellschaft, Berlin and Munich Translation: Siemens A&D Translation Services, Erlangen Publisher: Publicis Publishing, Erlangen © 2008 by Publicis KommunikationsAgentur GmbH, GWA, Erlangen This publication and all parts thereof are protected by copyright. Any use of it outside the strict provisions of the copyright law without the consent of the publisher is forbidden and will incur penalties. This applies particularly to reproduction, translation, microfilming or other processing‚ and to storage or processing in electronic systems. It also applies to the use of individual illustrations or extracts from the text. Printed in Germany Foreword The success story of Industrial Ethernet began in 1985 when Siemens presented the SINEC H1 based on IEEE 802.3. Especially because of its ability to exchange large quantities of data, Industrial Ethernet was predestined for use in production control systems. Three years later, special fieldbus systems such as Profibus start- ed to establish themselves for communication at the field level. These permitted fast and reliable exchange of data between controllers and distributed I/O devices. However, the increase in the volume of data to be transmitted resulting from in- creasingly intelligent field devices means that current fieldbus systems have reached their performance limits. With the first presentation of Profinet by PROFIBUS International in August 2000, Industrial Ethernet started to overcome this limitation. Profinet is making the way free for continuous communication from the field level up to the corporate management level. Profinet as an open Industrial Ethernet standard now satisfies all requirements for industrial applications. It is a standard which combines industrial perfor- mance and the strict real-time communication requirements necessary for motion control applications with the advantages of modern office communication. Profinet IO permits automation solutions to be implemented which were previ- ously exclusively reserved for fieldbus applications. Profinet CBA divides complex automation applications into autonomous technological modules of manageable size. In both cases, existing fieldbuses can be integrated into future structures us- ing proxies. Profinet is the first communications standard which permits both standard and safety-related communication over Industrial Ethernet. With the PROFIsafe profile certified in accordance with IEC 61508, Profinet satisfies the highest safety re- quirements for the process and manufacturing industries in accordance with SILþ3 and ENþ954-1 Category 4. Profinet offers a complete solution ranging from industry-compatible cables and connectors up to switches with real-time capability. A security concept specially tailored to automation engineering covers access control, data encryption, au- thentication and logging, and takes into account the high network security re- quirements. By means of Profinet, Industrial Ethernet has been “reinvented”, and its success story extended by a further chapter. It is also our hope with the second edition of this book that readers will become rapidly and practically acquainted with the topic of Profinet. In addition to correc- 5 Foreword tions, the previous focal points “Distributed I/O” and “Distributed automation” have been updated, and the new topic “Safety” included. This new edition would not have been possible without our readers and their in- terest in this exciting topic, without Siemens and its friendly support in all techni- cal matters. Thanks also to everyone who proof-read it in their free time and con- tributed to continuous improvement of the book with a wide range of constructive suggestions, and last but not least to our families for their understanding and pa- tience during many late nights. Sincere thanks to all! Erlangen, August 2008 Raimond Pigan Mark Metter 6 Contents 1 From Contactor to Open Standard . 13 1.1 The Simatic Success Story . 13 1.1.1 Change in Structure Through Decentralization . 15 1.2 The Road to Industrial Ethernet . 15 1.2.1 Industrial Ethernet . 17 1.3 Profinet . 18 1.3.1 Profinet IO . 19 1.3.2 Profinet CBA . 20 1.3.3 Real-Time Communication . 20 1.3.4 Fieldbus Integration . 20 1.3.5 Security . 21 1.3.6 Motion Control with Profinet . 22 1.3.7 Safety on Profinet . 22 2 Ethernet – Fundamentals and Protocols . 23 2.1 Fundamental Structure of Ethernet . 23 2.2 Standard Ethernet Frame . 24 2.3 Ethernet or MAC Address . 25 2.3.1 How to Find Out the MAC Address of an Ethernet Device? . 25 2.4 Shared Ethernet . 25 2.5 Switched Ethernet – Fast Ethernet . 27 2.5.1 Switches as Intelligent Star Distributors . 27 2.5.2 Full Duplex and Half Duplex Modes in the Switched Ethernet . 28 2.6 Functions for Ethernet . 29 2.6.1 Autonegotiation . 29 2.6.2 Autosensing – Automatic Recognition of Data Rate . 30 2.6.3 MDI/MDI-X Autocrossover . 30 2.7 Gigabit Ethernet – an Introduction . 30 2.8 10-Gigabit Ethernet . 31 2.9 Power over Ethernet (PoE) . 31 2.10 Protocols Based on Ethernet for Profinet . 32 2.10.1 TCP/IP . 32 2.10.2 UDP/IP . 38 2.10.3 Further Protocols of the Network Layer . 40 3 Real-time Communication . 42 3.1 Requirements of Ethernet with Real-time Capability . 43 3.2 Real-time@Profinet . 44 7 Contents 3.3 Real-time Communication . 47 3.3.1 Send Clock Time and Bandwidth . 48 3.3.2 Phase . 49 3.3.3 Reduction Ratio and Send Cycle . 49 3.3.4 Frame Send Offset . 50 3.3.5 Real-time Connection Management . 50 3.4 Isochronous Real-time Communication . 51 3.4.1 Isochronous Real-time Technology . 52 3.4.2 Configuration of IRT Applications . 53 3.5 Time Synchronization . 54 3.5.1 Time Synchronization Sequence . 55 3.6 Profinet Protocol Elements . 59 3.7 Profinet ASIC . 63 3.7.1 Application . 64 3.7.2 Development of Profinet IO Devices . 66 3.8 Protocol Analyzer for Profinet . 67 4 Profinet IO – Distributed I/O . 69 4.1 The Profinet IO Concept . 69 4.1.1 Profinet IO Device Classes . 71 4.1.2 Device Model of an IO Device . 71 4.1.3 Data Objects . 74 4.1.4 Context Management (CM) . 75 4.1.5 Application Relations (AR) . 75 4.1.6 Communication Relations (CR) . 77 4.1.7 Services and Protocols . 79 4.1.8 From Configuration to Up-and-Running System . 87 4.1.9 Proxy Functionality with Profinet IO . 87 4.1.10 Profibus Integration . 89 4.2 From Planning to Operation of a Plant . 91 4.2.1 Planning the Plant . ..