PROFIBUS Installation Guidelines - Verwer Training

1 PROFIBUS Installation Guidelines Revision April 2016 Verwer Training & Consultancy Ltd Contact information: Verwer Training & Consultancy Ltd 5 Barclay Road, Poynton, Stockport Cheshire SK12 1YY web: email: tel: +44(0)1625 871199 Copyright Verwer Training Consultancy Ltd, 2008-16 Installation Guide Page i Copyright Verwer Training & Consultancy Ltd, 2008 - 13 Table of Contents 1. PREFACE .. 3 2. INTRODUCTION TO FIELDBUS AND 3 PROFIBUS DEVELOPMENT AND HISTORY .. 4 THE PROFIBUS FAMILY .. 5 PROFIBUS FMS - Fieldbus Message Specification .. 5 PROFIBUS DP - Decentralised 5 PROFIBUS PA - Process Automation .. 5 PROFINET .. 6 The control system hierarchy .. 6 THE OSI MODEL.

2 8 Layer 1 The physical layer .. 8 Layer 2 The data link layer .. 8 Layer 7 The application layer .. 8 3. BASIC PROFIBUS NETWORKS .. 9 DEVICE TYP ES .. 10 NETWORKS AND 10 ADDRESSING .. 11 PROFIBUS DATA RATES .. 11 4. PROFIBUS NETWORK OPERATION .. 12 TOKEN PASSING .. 12 PLC PROGRAMMING .. 13 NETWORK 14 GSD files .. 14 BUS START-UP .. 15 DATA EXCHANGE .. 16 The watchdog 16 5. PROFIBUS PA .. 16 6. PROFIBUS Installation .. 18 PICK-UP IN FIELDBUS CABLES .. 18 Electrostatic pick-up .. 18 Electromagnetic pick-up .. 18 Pick-up reduction .. 19 PROFIBUS CONNECTION TECHNOLOGY .. 20 Balanced and unbalanced transmission .. 20 RS485 RULES .. 22 RS485 segmentation .. 22 Segment length considerations.

3 22 RS485 repeater limits .. 23 FIBRE-OPTIC TRANSMISSION .. 23 MBP TRANSMISSION .. 23 7. DEVICE ADDRESSING .. 24 SETTING ADDRESSES .. 24 Physical address switch on the device .. 24 Software setting of device address over PROFIBUS .. 25 Special software and communication link .. 25 SETTING AN ADDRESS ON A BINARY SWITCH .. 25 RESERVED ADDRESSES .. 25 Installation Guide Page ii Copyright Verwer Training & Consultancy Ltd, 2008 - 13 8. PROFIBUS RS485 WIRING .. 25 DP CONNECTORS .. 26 REFLECTIONS AND TERMINATION .. 27 The RS484 termination rules .. 29 SP UR LINES .. 30 PROFIBUS RS485 CONNECTORS AND WIRING TOOLS .. 31 PIGGY-BACK SOCKETS .. 34 COMMON RS485 WIRING ERRORS .. 34 9.

4 HAND-HELD CABLE TEST TOOLS .. 35 WIRING TESTING USING THE BT200 .. 35 Basic cable testing .. 35 Use of the BT200 keypad and display .. 36 Wiring testing using the COMSOFT NetTEST II .. 37 10. LAYOUT OF DP SEGMENTS .. 37 IDEAL SEGMENT LAYOUT .. 38 NETWORK LAYOUT WITH REPEATERS AND 40 M12 CONNECTOR SYSTEMS .. 41 WHEN ARE SPUR LINES ALLOWED? .. 43 SP ECIAL REQUIREMENTS FOR BIT RATES > MBIT/S .. 45 11. LAYOUT OF PA SEGMENTS .. 45 COUPLER AND LINK TECHNOLOGY .. 45 Simple DP/PA 46 Siemens DP/PA link module .. 46 Higher speed transparent couplers .. 47 MBP SPUR 47 MBP TERMINATION .. 47 INTRINSIC SAFETY 49 12. CABLES FOR 50 CABLES FOR PROFIBUS RS485 (DP) .. 50 CABLES FOR PROFIBUS MBP (PA).

5 50 13. INSTALLING PROFIBUS CABLES .. 51 GENERAL 51 JOINING CABLES .. 51 CABLE SEGREGATION .. 52 US E OF CABLE TRAYS AND CHANNELS .. 53 14. EARTHING CONSIDERATIONS .. 54 PROTECTIVE AND FUNCTIONAL EARTHS .. 54 PLANT EARTHING SYSTEMS .. 54 CABLING WITHIN WIRING CABINETS .. 55 POTENTIAL 56 MEASURING SCREEN CURRENT AND EARTH LOOP IMPEDANCE .. 57 15. FIBRE-OPTIC COMPONENTS .. 57 OPTICAL LINK MODULES .. 58 16. BIBLIOGRAPHY .. 59 INDEX .. 60 Installation Guide Page 3 of 61 Copyright Verwer Training & Consultancy Ltd, 2008 - 13 1. Preface PROFIBUS is an extremely flexible and reliable communication technology, however, like all high-speed digital communications systems, problems can be caused by a large variety of simple errors.

6 Sometimes these errors are caused by inappropriate or just plain wrong information that is handed down from people, who have extensive experience with traditional instrumentation and automation technologies, but little knowledge of high speed digital communications. Anyone involved with PROFIBUS at a technical level will require some Training . This includes not only installers but also system designers, maintenance technicians and automation engineers. The basics of high speed digital communications are not at all obvious. However, with good quality Training an understanding of the techniques and problems can be developed. This document forms a first introduction to PROFIBUS technology and covers the essential practical requirements for Installation and layout of networks that will operate reliably and that can be maintained with the minimum of disruption to plant operation.

7 The document forms the main text that covers the learning outcomes of the Certified PROFIBUS Installer course which is accredited by PROFIBUS International. This one-day course is appropriate not only for installers, but for anyone involved with PROFIBUS at a technical level. The document starts with an introduction to fieldbus and PROFIBUS for those that are not familiar with these technologies. It then goes on to provide simple practical guidance on the layout, Installation and static wiring testing for PROFIBUS networks. The main body of the document is concerned with the various rules and guidance on PROFIBUS DP and PA layout and Installation . The document provides not only the rules for Installation , but also the reasons for these rules.

8 Important Notice Although considerable care has been taken to ensure that the information contained in this document is accurate and complete, no responsibility can be taken for errors in the document or Installation faults arising from its use. 2. Introduction to fieldbus and PROFIBUS Fieldbus is a communications network designed for automation and control systems. There are many different fieldbusses in existence, but the most important are specified in the international fieldbus standard IEC 61158. Fieldbus is a digital communication network providing two way communications for devices that are mounted in the field in the factory or plant being controlled or automated.

9 Being a network, fieldbus can be used to communicate with many devices over one cable. Further, the communication is always two-way so, for example, sensors can not only communicate the process value back to the controller, but can also receive information for option settings, parameters etc. Devices can also report diagnostics and other maintenance information over the same fieldbus. The data communicated over the fieldbus can be diverse, from simple discrete devices that give only on/off values to sophisticated devices such as multi-function instruments, drives and servo systems. All can be combined on one fieldbus cable. Installation Guide Page 4 of 61 Copyright Verwer Training & Consultancy Ltd, 2008 - 13 The main advantages of fieldbus over traditional, separately wired, devices include the following: Reduction in the amount of wiring involved.

10 Cable supports, junction boxes and marshalling racks are also significantly reduced, saving cost, space and weight. The number of connections is drastically reduced. This is a very important consideration since connections are always a weak link, prone to problems such as water ingress, corrosion, high resistance, open and short circuits. Fewer connections can mean a more reliable system. Because of the more extensive data that can be transmitted, devices can show a level of intelligence that can provide self-diagnostic information, settings and parameters that can be downloaded over the network. This can drastically reduce the set up and commissioning time for a device. Fieldbus also makes it relatively easy to expand and modify the system.