Practical steps to a successful PROFIBUS project - Xiu Ji of the UK's PICC

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Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013.
Basics of PROFIBUS
Considerations at the design stage
Installation
Visual Checks

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Practical steps to a successful PROFIBUS project - Xiu Ji of the UK's PICC

  1. 1. Practical Steps to a Successful PROFIBUS Project Dr. Xiu Ji
  2. 2. Outline of this presentation Basics of PROFIBUS Considerations at the design stage Installation - visual checks Summary – Steps to a successful PROFIBUS project Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 2
  3. 3. Introduction to PROFIBUS Fieldbus is widely used in many automation systems. PROFIBUS solutions for Factory Automation (FA) and Process Automation (PA) Applications also involving drives, instruments, servos, robotics, functional safety, redundancy, and explosive environments etc. Extensive diagnostic functions available to operators and maintenance engineers Probably the single reason to use bus or networked devices and systems Diagnostic tools available for engineering, commissioning, maintenance, and fault finding Excellent support from PROFIBUS International, regional events and competence and training centres. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 3
  4. 4. More Information More adjustable settings and parameters (e.g. scaling, linearization and calibration). Diagnostic data to inform if measurement is valid. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 4
  5. 5. Extensive Diagnostics Controller SCADA/HMI 1 2 Engineering Station 3 PA Software 2 Analyser Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 5
  6. 6. The PROFIBUS Family PROFIBUS DP (Decentralised Periphery) Low cost, simple, fast for general automation applications Within short distances, in large quantities, mainly in-door, in dry areas, in cabinets Parameters, options and capabilities can be defined using a simple, text file, GSD file. Machines or a production line can be stopped in case of communication problems Physical layer uses RS485 or fiber optic Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 6
  7. 7. The PROFIBUS Family PROFIBUS PA (Process Automation) Developed specifically for the process industry to replace 4-20mA transmission Two-wire connection carrying both power and data Spread over long distances, in low quantities, mainly out-doors, in wet and exposed sites Parameters, options and capabilities are defined additional to a GSD file, also in EDD or FDT/DTM. Machines and processes cannot be stopped if there are only communication problems Large number of parameters, options and diagnostic events Cyclic and acyclic communications PA equipment is often used in explosive environments Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 7
  8. 8. Transmission Technologies PROFIBUS supports different transmission technologies HART on PROFIBUS LabAutomation XY Weighing & Dosage PROFIsafe, I&M, iPar-Server, Time Stamp, Redundancy, … Communication Technology Transmission Technologies .... PROFIBUS DP (DP-V0, -V1, -V2) Wired Optical RS485 / RS485 -IS MBP / MBP-IS Engineering Technologies GSD, EDD, FDT / DTM, TCI Common Application Profiles Encoder Ident Systems PA Devices Specific Application Profiles PROFIdrive Wired, Optical, and Wireless Wireless Glass, PC F, Plastic Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 8
  9. 9. Connection technologies 9 PROFIBUS DP uses 2-core shielded and twisted RS485 wiring. 9-pin sub-D or M12 connectors extensively used. DP can also use plastic or glass fibre optic cabling. ST/BFOC connectors widely used PROFIBUS PA uses “Manchester Bus Powered” (MBP) cabling over 2 cores. Glanded screw or M12 connection normally used Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 9
  10. 10. Fibre Optic The implementation of a fibre optic cable network involves the use of electro optical converters (OBT and OLM): for long distance, between buildings, and to solve grounding problem (grounds with un-even earth potential). OLM (Optical Link Module) OBT (Optical Bus Terminal) Fibre to Copper Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 10
  11. 11. Control System Architecture Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 11
  12. 12. From DP (RS485) to PA (MBP) 1 1 1 4 To 7 volts 0 0 PROFIBUS PA, MBP PROFIBUS DP, RS485 Current/mA 0 1 1 0 0 +9mA 10 mA -9mA time Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 12
  13. 13. DP & PA Segments One PROFIBUS network can host up to 126 stations (masters and slaves) – capacity of a PROFIBUS DP master Limitation of RS485 and MBP – 32 loads and total cable length per segment Segment 1 RS485 M Repeater S Segment 2 RS485 S Segment 3 Fibre Optic S S R S O S DP/PA Coupler C S S O S S Segment 4 RS485 S M Fibre optic links S S Segment 5 MBP Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Page 23 Slide 13
  14. 14. Segmentation, PA The maximum number of devices on a PA segment is the same as the maximum on a DP segment, which is 32. However, how many slaves can be connected to a PA segment depends primarily on the power supplied to the segment. Segment Coupler V = 13.4 VDC, I = 100 mA Maximum number of PA slaves = 100 / 14 = 7 I actual = 5 x 14 = 70 mA 14 mA 14 mA 14 mA #13 14 mA 14 mA #16 T #17 #15 #14 Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 14
  15. 15. Reflections When electrical signals travel down a cable, any electrical discontinuity can cause reflections to occur. The end of the cable in particular is a major discontinuity, which can cause severe reflections. Just like an echo, the reflected signal can cause multiple signals or corrupted telegrams to appear on the line. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 15
  16. 16. Reflections Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 16
  17. 17. Termination - Rules To avoid reflections from the ends of the cable it is essential that each segment is terminated at the two ends and nowhere else. Two terminators in each segment must be powered at all times. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 17
  18. 18. Termination Standalone termination boxes are available. for DP, and for PA. Termination on Repeaters Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 18
  19. 19. Termination #10 #0 #1 #11 T T DP/PA coupler Power supply for PA segment T T 1 network with 2 segments. #13 #15 #14 #16 Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. #17 Slide 19
  20. 20. Causes of Reflections Missing terminator Un-powered terminator Terminator switch - faulty Extra terminator Reflection can also be caused by:  Un-certified devices. Cable length between two devices is too short. Spurs are used in high speed networks. Wrong types of cables are used. Cores are sharply bended. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013.  Page 31 Slide 20
  21. 21. Interference 2 1 Interference is picked up from adjacent equipment or connected equipment with poor Electromagnetic Compatibility (EMC) rating. Interference can be caused by: Inadequate earthing of equipment, Poor or incorrect earthing of cable shield, Insufficient segregation of power and bus cables, Routing cables through electrically noisy areas, and Heavy earth currents on the cable screen. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 21
  22. 22. Equipotential Bonding Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 22
  23. 23. Installation: Shielding and Grounding intern 2 3 Shielding and Grounding The recommended grounding practices: Connect all PROFIBUS interfaces and cable shields to ground. Use a grounding cable to go from cabinet to cabinet in the same segment – equipotential bonding. Types of grounding: Direct grounding (at any connecting point) Capacitive grounding Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 23
  24. 24. Grounding of devices and shields Connect the PROFIBUS cable shield to the equipotential bonding at every PROFIBUS station assuming local potentials are equal! Connector Shielded, twisted-pair cable Red = + Green = - Screw terminals Rx Cable shield route to ground Rx Tx Tx Device Device Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 24
  25. 25. Wrong connectors Which connectors are faulty? A B C Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. C Slide 25
  26. 26. Cable Segregation • All channels and partitions must be properly earthed. • Use flexible bonding links are protected against corrosion. • Braided straps are better than solid metal. Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 26
  27. 27. Cable Segregation Distance In general, the greater the spacing between the cables and the shorter the paths run parallel, the lower the risks of interference. Recommended cable segregation distances:  20 cm Cable Category I  10 cm  50 cm Cable Category II  10 cm Cable Category III  50 cm Cable Category IV Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013.  50 cm Slide 27
  28. 28. Cable Segregation ? An example: frequent converters. Can you spot the error here? Power able route Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 28
  29. 29. Spot the errors Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 29
  30. 30. Spot the errors Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 30
  31. 31. Spot the errors Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 31
  32. 32. Use PROFIBUS connections - DP Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. 3 2 Slide 32
  33. 33. Use PROFIBUS connections - PA 3 3 Trunk PROFIBUS DP Link/ Coupler T T PROFIBUS PA Spur lines Devices PROFIBUS DP Link/ Coupler T Junction Box PROFIBUS PA Junction Box Trunk T Spur lines Devices Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 33
  34. 34. Spot the errors Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 34
  35. 35. Design considerations - details Limitations of segment loads and total cable length Standalone terminations for DP, redundant power supply to terminators Network drawings – node addresses, position of termination, cable length between connectors and junction boxes, trunk cable and drop cable length Piggyback connectors – spare connection into EVERY segment for voltage measurements and troubleshooting Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 35
  36. 36. Design considerations - architecture Which network to use – PROFIBUS, PROFINET, DP, PA, AS-i? 3 6 Designation of safe and explosive areas Production and functional safety systems Cable routes – fibres, copper cables, earthing systems, equipotential bonding cable in place? Cabinet or field assembly Connection of devices via remote IO or integrated fieldbus? Use of redundancy at difference levels Network and device access for engineering, monitoring and maintenance Design documents and drawings Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 36
  37. 37. Installation Checklists 3 7 Checklist to determine network topology and obtain the network drawing Checklist for PROFIBUS DP (RS485) Grounding Checklist for PROFIBUS PA (MBP) Grounding Checklist for PROFIBUS DP (RS485) Cabling Page 73 Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 37
  38. 38. Practical steps to a successful PROFIBUS project The very first step to a successful project should be 3 8 Training PROFIBUS training courses are available for: Designers, Installers, Commissioning Engineers, and Maintenance staff. Many industry sectors specify that their staff, contractors and sub contractors must be appropriately trained. PI Competence Centre - Manchester Metropolitan University, in-house or on-site training PI Training Centre – Verwer Training and Consultancy, on-site training for min. 6 people Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 38
  39. 39. Summary: Steps to a successfully project 3 9 1. Design staff should be trained before the design starts. 2. Everyone involved in the project at a technical level is trained to an adequate level, at the least to the designer or installer level. 3. Make sure that designers are fully aware of the methods for diagnosing and locating faults. 4. Ensure that health checking and performance monitoring facilities are incorporated into the network. 5. Follow the extensive guidance that is available from PI and from competency and training centres, for example, incorporating the checklists into your installation acceptance tests. Reference (Page 79) Practical steps for a successful project, Xiu Ji. PROFIBUS Seminar at MTC, Coventry, 2013. Slide 39

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