FIELDBUS Industriell datakommunikation Luca Beltramelli Email: - PowerPoint PPT Presentation

FIELDBUS Industriell datakommunikation Luca Beltramelli Email: luca.beltramelli@miun.se Mittuniversitetet

References Books: • Practical Industrial Data Communications by Reynders, Deon Mackay, Steve Wright, Edwin • Industrial Communication Systems by Wilamowski, Bogdan M. Irwin, J. David Mittuniversitetet Industriell Datakommunikation - Fieldbus 2

Program 04/05/2018 • Seminar I: • Introduction to Fieldbus and Industrial Automation • Overview of fieldbus technologies (Part 1) 07/05/2018 • Seminar II: • Overview of fieldbus technologies (Part 2) • Real Time Ethernet • WirelessHART Mittuniversitetet Industriell Datakommunikation 3

Control System + Reference Set CONTROL ACTUATOR PLANT ALGORITHM - Feedback SENSOR Control System Mittuniversitetet Industriell Datakommunikation 4

Networked Control System Controller(s) Communication Sensor(s) Actuator(s) Network Mittuniversitetet Industriell Datakommunikation 5

What is a Fieldbus? Fieldbuses are real-time networks for sensors and actuators. Used for the communication among sensors, actuators and controllers Data and Nodes Management Fieldbus Diagnostic Safety and and Security Integration Mittuniversitetet Industriell Datakommunikation - Fieldbus 6

Real Time “ A real-time system is one whose logical correctness is based on both the correctness of the outputs and their timeliness ” Soft vs Hard Real Time Failure to meet deadline HARD RT SOFT RT Catastrophic Failure Performance degradation Mittuniversitetet Industriell Datakommunikation 7

The Automation Pyramid Office Network : TCP IP, Ethernet Plant Network : Ethernet, ControlNet Fieldbus : FF, PROFIBUS PA, LON Simple fieldbus or Sensor Bus : CAN, DeviceNet, SDS, ASI-bus, Interbus-S Mittuniversitetet Industriell Datakommunikation - Fieldbus 8

Fieldbuses: the beginning Traditionally in industries the communication was completly analog Moving to digital communication brings many benefits: • Immunity to noise; • Less cabling; • Better Diagnostic; 20 Fieldbus replace the traditional 4 – 20 mA analog technology. [mA] 4 Measurement Range Mittuniversitetet Industriell Datakommunikation - Fieldbus 9

4-20 mA vs Fieldbus 4-20 mA Fieldbus Information Analog Digital Signal Integrity Low (EMI, High Attenuation, ...) Communication Phyisical Physical, Data Link, Layer Application Diagnostic Minimal Extensive Installation cost High Low Cost per device Low High Mittuniversitetet Industriell Datakommunikation - Fieldbus 10

Fieldbuses: field devices One of the key requirements for the adoption of fieldbus is the distribuited intelligence. To access the fieldbus sensors and actuators are required to implement a communication stack. Smart Sensors : • Computetion capabilities; • Communicate in a digital way; • They use a communication standard (at least layers 1 and 2 of ISO/OSI); Mittuniversitetet Industriell Datakommunikation - Fieldbus 11

Fieldbus Evolution From the first proprietary solutions (’80) to the actually used standard (’90) International Predecessors Proprietary solutions Standards 1991 … 1996 1969 1979 First PLC (Modicon 084) MODBUS CAN Profibus FMS/DP/PA HART FOUNDATION fieldbus Mittuniversitetet Industriell Datakommunikation - Fieldbus 12

Fieldbus Evolution From the first proprietary solutions (’80) to the actually used standard (’90) Industrial Ethernet Wireless Networks 2001 … 2006 2007 2009 2010 EtherCAT (2003) Eth/IP (2001) Profinet (2004) SafetyNET (2006) … Release of WirelessHART Release of ISA100.11a Introduction of IO-Link Mittuniversitetet Industriell Datakommunikation - Fieldbus 13

Fieldbus and the OSI Model Layer ISO/OSI Model Layer ISO/OSI Model 7 Application 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data link 2 Data link + MAC 1 Physical 1 Physical Implementation Model OSI Model Mittuniversitetet Industriell Datakommunikation - Fieldbus 14

Fieldbus: the applications Factory Automation Process FIELDBUS Automative Automation Home Automation Mittuniversitetet Industriell Datakommunikation - Fieldbus 15

FIELDBUS FOR AUTOMOTIVE Safety • Redundancy, Check codes, very low data error rate Determinism • Synchronized communications, TDMA Wireless networks are considered unreliable and, up to now, are used for entertainment and extravehicular communications IEEE 802.11p for data exchange between high-speed vehicles (V2V) in the licensed ITS band of 5.9 GHz (5.85-5.925 GHz). Examples: LIN – very simple protocol (e.g. window automation) CAN – CAN version with TDMA (e.g. ABS) FlexRay – New (BMW, Audi, Mercedes …), increases baud rate with respect to CAN (up to 10Mbytes/s) and adopts a TDMA with dynamic slots assignment. Mittuniversitetet Industriell Datakommunikation - Fieldbus 16

FIELDBUS FOR HOME AUTOMATION The low-cost is mandatory, non-invasive and mobile sensors could be the future (wireless fieldbuses) Primary needs: low-cost, simple installation, auto-configuration There are a lot of proprietary solutions: • CAN – based solutions (different application layers) • Some emerging Ethernet-based solutions (security and costs problems) • EIB, EHS and Batibus converge into Konnex (KNX) (ISO/IEC 14543- 3,EN50090) • European Standard (Siemens, ABB, Bticino, Vimar, etc.) • Wired and wireless • LONWorks • Widespread in USA • Supported by electronic devices (Neuron Chips produced by Toshiba, Freescale, Cypress) Mittuniversitetet Industriell Datakommunikation - Fieldbus 17

FIELDBUS FOR PROCESS AUTOMATION • Safety is mandatory (particularly in chemical, oil, industries,…) • High availability (redundant system) • Reduce wiring (long distances) - the bus also powers the devices • Speed is not important • Cycle time are in the order of several hundreds of ms • Timestamp is important in case of fault (resolution ~ 100 ms) There are only two big players: • PROFIBUS PA • F IELDBUS F OUNDATION (it has local loop control between devices) They use the same physical layer (Manchester, powered, 31.25kbaud) but they are totally different at the data layer. Wireless can be used for non critical processes, as it reduce wiring and allow a range extension by suitable network topologies (mesh) Mittuniversitetet Industriell Datakommunikation - Fieldbus 18

FIELDBUS FOR FACTORY AUTOMATION The main goals are: • Fast and low-cost • High rejection to noise • Safety (e.g.protection of human operator) Speed can be very important • Reduced communication times means more products, i.e. higher gain… • Motion control (motor drives) need isochronous communication More than 20 fieldbuses for Factory Automation • PROFIBUS DP is the most diffused but holds only the 15% of the market (RS485, max 12Mbit/s) • DeviceNet , CANOpen , use CANbus (max 1Mbit/s) Factory environment is hostile for wireless technology (metal, walls ,…) Mittuniversitetet Industriell Datakommunikation - Fieldbus 19

The Ideal Fieldbus: some characteristics • Transfers a “big number” of small data; • Supports real-time traffic (Upper bounded response times, ex. 1ms..1s) ; • Operates in hazardous environments (high temperature, vibrations, etc.) ; • Is robust and easy to install; • Has high availability (e.g. redundant architectures) ; • Has continuous supervision and diagnostic; • Manages long distances (100m .. 4 km) ; • Has good data transmission rate (e.g . 50 kbit/s … 5 Mbit/s) ; • Supports clock synchronization (e.g. milliseconds up to microseconds) ; • Manages non real-time traffic for maintenance and diagnosis. Mittuniversitetet Industriell Datakommunikation - Fieldbus 20

Fieldbus: the topology Fieldbus daisy chain topology Tree topology • Flexibility of the hardware of the measurement system • Cable reduction • Every node can share information with other nodes • Different delays from node to the measurement system • Less realiable Mittuniversitetet Industriell Datakommunikation - Fieldbus 21

Fieldbus: distributed measurements In Industry to ensure good control and monitoring actions, sensor nodes should… A. Be synchronized • Synchronization protocols • Delay • Jitter B. Be identified and localized • Identifier for each sensor • Localization of moving sensor C. Be qualified • Uncertainty measurement • Status report Mittuniversitetet Industriell Datakommunikation - Fieldbus 22

Fieldbus: Measurement and Control Measurement Loop Control • • Data require a time reference Delay must be limited (timestamp) (deterministic transmission) Mittuniversitetet Industriell Datakommunikation - Fieldbus 23

Fieldbus: Networked Control System (NCS) Process Actuator Sensor Communication Network Controller Close loops in Process Automation Close loops in Factory Automation • Process (temperature, humidity,… T cycle > 1s) • Motion (positioning, speed, torque… T cycle < 1 ms) Mittuniversitetet Industriell Datakommunikation - Fieldbus 24

Fieldbus: a complex scenario Seriplex Ethernet Profibus-FMS CAN Batibus WorldFIP FlexRay Profibus- CANOpen PROFInet PA AND MANY OTHERS EtherLink Profibus-DP FieldBus Sercos !!! Foundation BacNET ControlFIP Hart IEEE 802.11 ModBus-RTPS DeviceNet M-Bus Modbus Profisafe ControlNet Ethercat Mittuniversitetet Industriell Datakommunikation - Fieldbus 25

HART Mittuniversitetet