Fieldbus wireless: dal manifatturiero al processo

Transcription

1 Eventi PNI 2011 Fieldbus wireless: dal manifatturiero al processo Emiliano Sisinni, Paolo Ferrari Università di Brescia DII Via Branze, BRESCIA Tel PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 1 Why wireless now? Wireless isn't new. Why all the recent interest about it in industries applications? Consider what happened with cell phones. Cellular technology was available for at least a decade before it was widely adopted, but the large size and short battery life of early phones made them impractical for most people. Once those problems were solved, adoption increased exponentially. Something similar has happened with wireless technology for process and factory automation. It wasn't hard to see the potential benefits, but users were reluctant to put wireless to work in their plants until concerns about security, battery life, standards, and communication reliability were addressed. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 2 profibus@csmt.it 1

2 Market Opportunity According to a research conducted by ON World, there will be 20 million wireless enabled sensing points worldwide in The industrial WSN market will be a multibillion dollar opportunity at this time including wireless networking equipment, software and services. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 3 An example: oil & gas industries this wireless technology enabled us to do things we simply could not do before, either because of cost or physical wiring obstacles. Through the trials, we found that the wireless approach is flexible, easy to use, reliable, and makes a step-change reduction in installed costs." Dave Lafferty BP Wireless truly is faster and cheaper. It just worked! Brandon Robinson EnCana Savings of a 5-node installation: 250m conduit 1km wire 2 guys, 2 full days of labor no trenching or surveying for buried cable PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 4 profibus@csmt.it 2

3 Inhibitors However, nowadays there is still confusion about wireless and psychological inhibitors. The result of ON World phone interviews with 105 plant managers, process engineers, and systems integrators reported data reliability as both the most intriguing adoption factor and the greater inhibitor! PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 5 Why wireless now? Nowadays, industry ready" wireless solutions are increasingly available. Built-in encryption, authentication, verification, key management, antijamming, and other security measures can make properly-implemented wireless networks as secure as many traditional wired ones or more so. Advanced power-management techniques, low-power electronics, and energy scavenging technologies help minimize power consumption so wireless devices can operate for years without battery replacement. Self-organizing networks offer unprecedented reliability for wireless field networks, even when changes in the plant environment interfere with existing transmission paths. Emerging industrial standards -- such as those under development by HART Communications Foundation and PI -- are addressing concerns about integration and long-term compatibility in wireless field networks. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 6 profibus@csmt.it 3

4 Standards Metropolitan networks - Wireless MAN (WMAN) WiMAX Cellular (GSM, GPRS, EDGE, UMTS ) Local networks - Wireless LAN (WLAN) WiFi, HIPERLAN DECT BAN: Body PAN: Personal LAN: Local MAN: Metropolitan WAN: Wide Area Network Short range networks - Wireless PAN (WPAN) Bluetooth, ZigBee, Z-Wave, WiBree, nanonet, UWB, Wireless USB, WirelessHD, WirelessHART, WSAN-WISA, ISA100, RFID, 6LoWPAN, WirelessFirewire,. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 7 What kind of wireless applications? There is no One Size Fits All!! kbps Data Rate Mbps Km Distance 100 m transmitters (a, b, g etc) (a, b, g etc) (a, b, g etc) WSN Proprietary wireless Wi-Fi standards (a, b, g etc) PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 8 profibus@csmt.it 4

5 Wireless applications Wireless reduces mounting errors and it makes easier to scale inplant network, avoiding cabling! Sometimes even moderate distances or other barriers (such as highways or rivers) can make a wired connection simply too expensive or difficult to install: near-plant applications Finally, wireless technology makes sense when a hard-wired connection is impractical, e.g. the sensing point is many kilometers from where you'll use it! PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 9 PA/FA requirements Continuous Process Manufacturing Discrete Manufacturing Process Attribute Sensor types Predominately Analog Predominantly Discrete Sensor count per unit Unit Physical Size 1000 Meter 10 Meter Units per Plant 10s 100s Production Cycle Length 100 Days 1 Day Unit Startup Time Hours Minutes Control Loop Time Sec Sec Field Device Cost $1000 $100 Installation Cost/device cost 10 X 4 X Automation Technology DCS PAC/PLC Commonly Used Solutions HART, Foundation Fieldbus, Profibus-PA, Ethernet Profibus-DP, DeviceNet, Interbus, AS-I, Ethernet PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 10 profibus@csmt.it 5

6 PA/FA requirements Requirements to similar variables But very different values Installation Cost/device cost 10 Field Device Cost [$] Device count per unit Continuous Process Manufacturing Unit Predominantly Analog Discrete Manufacturing Unit Predominantly Discrete Unit Physical Size [Meter] Units per Plant 100 Attention: Logarithmic Scales! 1 0,1 Time: slow [sec.] 0, ,01 0,001 0,01 0,1 1 Device density (in unit) Time: control loop [sec.] Devices per Plant Time: fast/ sub-unit [sec.] Unit Startup Time [minutes] 1000 Production Cycle Length h not one technology for all solutions: how to choose the right one? PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 11 The iwlan IEEE adaptation to industrial scenario; proposed by Siemens Determinism is ensured thanks to band reservation (TDMA coexists with CSMA/CA; allowed by IEEE PCF, improved in ipcf) RF channel redundancy; cell redundancy (overlapping) Fast roaming among different Access Points (<50ms with ipcf) Transparent integration with PROFINET and PROFIsafe Hall 1 Hall 2 Robust Access Point Scalance W Hall 1 Industrial Ethernet... PLC Station PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 12 profibus@csmt.it 6

7 iwlan: applications PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 13 Network topologies Star topology Mesh topology Cluster-tree topology Router Node Controller Router Node Node Controller Node Controller Repeater (optional) A star topology may be acceptable in fast applications (low latency), but requires a plant survey to ensure reliability. If data reliability is crucial, mesh topologies will best guard against data loss or signal degradation with the added benefit of allowing easy network expansion. A cluster tree may be used if you want to apply different topologies to different parts of the network. For example, battery-powered measurement devices can be linked in a star topology to line-powered routers, which can then be linked in a mesh topology. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 14 profibus@csmt.it 7

8 Choosing the right topology Each topology has its own strengths and challenges. So which is right for you? The answer is simple: The one whose characteristics best fit the most important requirements of your application. A star topology may be acceptable in fast applications (low latency), but requires a plant survey to ensure reliability. If data reliability is crucial, mesh topologies will best guard against data loss or signal degradation with the added benefit of allowing easy network expansion. A cluster tree may be used if you want to apply different topologies to different parts of the network. For example, battery-powered measurement devices can be linked in a star topology to line-powered routers, which can then be linked in a mesh topology. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 15 Self-organizing network In a self-organizing network, every wireless device and gateway has the capability to act as a router for other nearby devices. But instead of having every device talk with every other device all the time, the devices and gateways work together to identify and use the most efficient communication path for each message: If a device is within range of a gateway, direct point-to-point transmissions allow low power consumption (especially when combined with technology that minimizes the need for communication "re-tries"). Network expansion is easy. A new device can communicate with the nearest device or gateway which recognizes the new device as an authorized node on the network, and knows when to receive and transmit its messages. If a communication path is disrupted, the network's "self-healing" capabilities automatically re-route messages along the next-most-efficient route. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 16 profibus@csmt.it 8

9 The WirelessHART Initiative launched by HCF in November Standard in September Now IEC approved (Committee 65C WG 16). Supported by PI for PA wireless applications Objective: Establish a wireless communication standard for process automation, in particular for IN PLANT applications WirelessHART: wireless extension to HART protocol Based on IEEE STD (the same of ZB!) TDMA using timeslots organized into superframes Full wireless mesh network Highly secure communications using AES-128 block ciphers with individual Join and Session Keys and Data-Link level Network Key Self-organizing capability PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 17 The WirelessHART network HCF consortium PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 18 profibus@csmt.it 9

10 The WirelessHART Adapter Wireless Access to any HART Device Specified Requirements Support Multi-dropped HART Devices Automatically Route Messages Wireless to Wired and back Publish Measurement and Control Data for attached HART devices Well specified set of commands Gateway supports Adapter commands Acts as HART Master and Slave Like a special Remote I/O Poll devices as needed Request - Response Smart Data Publishing Notification by Exception Transparent Message Routing 19 Block Transfers Request - Response AT204 WirelessHART Adapter Examples - Many other uses of Adapters Possible TT206 HART PID Device Family VF206 PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 19 Channel Hopping and TDMA To enhance reliability, Time Division Multiple Access is combined with channel hopping. It provides frequency diversity, which can avoid interferers and reduce multipath fading effects. TDMA enables efficient, low power and reliable channel hopping communication because the synchronization of the slot and channel Devices rendezvous in time and frequency, thus promoting successful communications. 5MHz 3MHz F[GHz] Channel Cycle N 1 Cycle N 1 Cycle N+1 Cycle N+2 Time slot Link Time Superframe PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 20 profibus@csmt.it 10

11 Security The specific messages that are protected by the security functionality are: single hop MAC sublayer protocol data units, end to end network/transport layer protocol data units, and management of keys within the Application Layer protocol data units. Denial of Service Attacks Trusted Node Access DCS Critical Measurements Wired 128Bit Key Codes Communication Analysis Encrypted Communication Encrypted Messages Individual Session Key Spoofing PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 21 Security: Join the network Put JOIN key and into Network_ID the WirelessHART Field Device using standard tools (handheld device, compulsory wired link) Listen to advertise packets from neighbours Connect to a neighbour using JOIN key to authenticate Neighbour uses NETWORK key to pass message up to gateway Gateway determines optimized schedule Schedule is flooded to the devices PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 22 profibus@csmt.it 11

12 Cooperation for PA Major fieldbus standards cooperate for a uniform wireless solution Profibus International is part of the WCT WCT Wireless Cooperation Team HART COMMUNICATION FOUNDATION PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 23 Learn more WirelessHART consortium organizes FREE seminars PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 24 profibus@csmt.it 12

13 ISA100 What is it? Defines procedures for implementing wireless systems in the automation and control environment with a focus on the field level. IP based Internet of things ( e.g. 6LowPAN) 25 ISA Oct Ira Sharp Interface 10/21/2008 PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 25 ISA100.11a Update ISA100.11a Draft 2 (10/14) Failed to pass (63% Supported) Now for Draft 3 ISA100.11a Key Components Low Energy Wireless Infrastructure Robustness Coexistence Interoperability (IP based) PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 26 profibus@csmt.it 13

14 The Geographic Networks Objective: Establish a wireless communication standard for process automation over long distances (E.g. water and oil& gas) Use of public infrastructure: GSM/GPRS/UMTS network Many times there is an integrated TCP/IP stack that allows the implementation of simple control systems into the GPRS network. As the valve shaft is not connected to the public electric grid, the energy must be provided in another way. Therefore, the compact control system may be supplied by solar energy. The solar modules generate enough electricity to supply the GSM/GPRS control system or other devices with energy and recharge the solar batteries. The size of the system is such that there is sufficient solar power even on short, dark winter days. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 27 Topology over a wide area The logical topology is a long backbone that links cluster of sensors and actuators. PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 28 profibus@csmt.it 14

15 Topology over a wide area The physical topology is a star-cluster Long range, point to point, (private) wireless? To be investigated PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 29 Conclusions Wireless is a hot topic in industrial applications Some troubles as power supplies/cost still exist Thanks to the advent of standard solutions for both Factory and Process Automation, its adoption may be larger and larger Leader technologies are already available PROFIBUS PROFINET is deeply involved! wire less PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 30 profibus@csmt.it 15

16 Seminario gratuito gratuito WirelessHART Università Universitàdi di Brescia Brescia Giugno GRAZIE PER L ATTENZIONE! emiliano.sisinni@ing.unibs.it paolo.ferrari@ing.unibs.it PROFIBUS & PROFINET Competence Center 2011 Università Brescia - CSMT Gestione P. Ferrari E.Sisinni 31 profibus@csmt.it 16