Supervisory Control & Data Acquisition

1. Supervisory Control & Data Acquisition Communication Technology

2. Seriplex FAQ • CAN FAQ • Interbus S FAQ • IBS club • WorldFIP • LON works • Modbus • Fieldbus compare • Honeywell • Control competition Which Network Do I Use? Modbus Interbus S Modbus Plus ASI Profibus Echelon CAN Ethernet Device Net SDS Seriplex

3. What is a Network ? • A group of devices physically connected together for the purpose of sharing information, resources and a common transmission medium.

4. Why do you need a network? • Control the flow of information • security, accessibility, data control • Centralize resources • save cost on local work stations and peripherals • Simplify data / software management • Backups, IS maintenance • Share information with multiple users • Distribute tasks • reduce local need CPU power

5. What makes a network work ? • Computers, printers …... • Network interface cards • Network adapter Software drivers • Network Cabling • Network protocols

6. The Basic Types of Networks • Master / Slave (Similar to the teacher- student relationship) • Peer to Peer (Similar to the workgroup concept) • Client / Server (Similar to an automated teller transaction)

7. Slave Slave Slave Master / Slave Network • Central Control and Administration • Central Processing of Information • Polling of Stations Master

8. Peer To Peer Network • Distributed Administration • Independent Processing of Information • Shared Transmission Medium

9. Client / Server Network • Central Network Administrator • Controlled Flow of Information • Independent Processing of Information • Shared Transmission Medium

10. Application Layers Designed for Data Processing Presentation Session Transport Network Layers Designed for Communications Datalink Layer Physical Medium How is a network put together ? • The OSI model uses 7 layers to categorized the main elements of a basic network

11. Application Application Presentation Presentation Session Session Transport Transport Network Network Datalink Layer Datalink Layer Physical Medium Physical Medium OSI Model Layers • A Model is used to ensure Compatibility • Each station utilizes the same Protocol Stack

12. Application Presentation Application Presentation Session Transport Session Network Transport Datalink Layer Network Physical Medium Datalink Layer Physical Medium OSI Model: Flow of Data • Logical Structure • Data Multiplexing

13. Application Presentation Session Transport Network Datalink Layer Physical Medium Hardware / Software integration • The upper five layers are implemented with software • The lower two layers are implemented with hardware Software Layers Hardware Layers

14. Application Presentation Session Application Transport Transmission Control Network Internet Protocol Datalink Layer CSMA - CD Physical Medium Twisted Pair/ Fiber Optics OSI Model vs. Ethernet -TCP/IP • Ethernet does not incorporate all 7 layers because it’s development predated the OSI model CDMA/CD – Carrier Sense Multiple Access with Collision Detection

15. Application Presentation Session Transport Network Application Datalink Layer ASIC Dependent Physical Medium Multiple Mediums OSI Model vs. Field Bus Model • The typical field bus only utilizes 3 layers. The functions of the other layers are either built into the ASIC chip or the application layer ASIC - Application-Specific Integrated Circuit

16. What is common to all networks ? • Application message - dependent on software package • The message is created by the application package • Media Access Control • The procedure for sharing the physical medium • Logical Topology • The associations between the devices • Physical Topology • The layout of all the device connections • Transmission Mediums • The physical path used between the devices

17. Jacket of PVC or Teflon Jacket made of PVC or Teflon Various Transmission Mediums • Coaxial Cable • Twisted Pair • Optical Fiber • Wireless

18. Basic Physical Topologies • Bus Topology • Star Topology • Ring Topology • Free Topology • Hybrid Topology

19. Bus Architecture Topology • Single Channel - Broadcast oriented • More delicate to maintain signal integrity based on cable selection, distance and drops/taps

20. Star Architecture Topology • Central Hub • multi-port repeater • Loose star = lost network • channel selecting switch

21. Ring Architecture Topology • Each device is a repeater • Loose node= broken ring

22. Star term. Loop Bus Free Topology • Devices are wired in any combination of topologies • Usually requires one terminator

23. Hybrid Architecture Topology • Non-rooted Tree Architecture (ex.- Internet)

24. Gateway Network Extenders Repeater and Hub • Repeater and Hub • Bridge • Router • Gateway Bridge Router

25. Application Application Presentation Presentation Session Session Transport Transport Network Network Datalink Layer Datalink Layer Physical Medium Physical Medium Physical Medium Physical Medium Physical Layer Network Extenders • Repeater or Hub • Active repeaters regenerate the signal (store and forward) • Passive repeater amplifies the signal; adds no latency

26. Application Application Presentation Presentation Session Session Transport Transport Network Network Datalink Layer Data Link Layer Datalink Layer Data Link Layer Physical Medium Physical Medium Physical Medium Physical Medium Data Link Layer Network Extenders • Bridge or Level 2 Switch

27. Application Application Presentation Presentation Session Session Transport Transport Network Network Network Network Datalink Layer Datalink Layer Data Link Layer Data Link Layer Physical Medium Physical Medium Physical Medium Physical Medium Network Layer Network Extenders • Router or Level 3 Switch

28. Application Application Application Application Presentation Presentation Session Session Transport Transport Network Network Datalink Layer Datalink Layer Physical Medium Physical Medium Application Layer Network Extenders • Gateway

29. Bridge Router Network A Router Network B Logical Terminology & Topologies Node • Node • Segment / Channel • Subnet • Network • Domain • System Segment Segment Subnet Subnet Gateway Domain A Domain B

30. Node Node ID Parameters Data A Node • A collection of SW objects that communicate over a network based upon a single hardware ID. • A physical device may contain one or more nodes • Example - a router

31. Segment Node Node Node Node Node Node Segment / Channel • One or more nodes electrically connected to a continuous section of a transmission media • May include the trunk line, drop line, multi-port taps and other cable components.

32. Segment Segment Segment Subnetwork (Subnet) • One or more nodes sharing a common protocol and a media access arbitration method • May contain multiple segments Subnet

33. Network • One or more subnets using a common network level protocol where each hardware ID is unique on the network • May contain multiple subnets Network

34. Domain Network Network Network Network Router Gateway Domain • One or more networks where each network has a unique ID within the domain • May contain a variety of network types connected together with gateways and routers

35. Domain Domain Domain System • One or more Domains System

36. Basic Media Access Control Methods • Time Division Access • Polled Access • Token Access • Carrier Sense Multiple Access How will they share the common media ? NODE #2 NODE #12 NODE #10 NODE #5 Token

37. Time Division Access • Utilizes a master clock • Each device is assigned a slice of time

38. Slave Request Frame immediate response Master DP-Slave Header Input Data Trailer Trailer Output Data Header Response Frame Polled Access • Utilizes one device as a master • Other devices a considered slave devices • The master requests information from each slave • The slave responds to the request

39. Token Access • Every device is considered equal • A token is used to administer access rights • The token is passed logically among the devices • Requests are initialized when a device possess the token Message Message Message Message Token Token Token Token Token Token Token Message Message NODE #2 NODE #12 NODE #10 NODE #5 Token Token

40. Carrier Sense Multiple Access • No priority is assigned to the devices • All the devices contend for access • Messages are only sent if the shared media is not in use Message Message Message Message Message Message Message Message Message Message Message NODE #2 NODE #12 NODE #10 NODE #5

41. Application: message specifications Various Media Access Methods: ASIC Dependent Multiple Mediums & Physical Topologies Typical Automation Field Bus Model • The typical field bus only utilizes 3 layers. The functions of the other layers are either built into the ASIC chip or the application layer • The application layer will characterize the overall function of the field bus or the network.

42. Operations Level Data Network Management Level Control Network System Level (Cell) Device Bus / Field Bus Process Level Sensor/Actuator Bus Sensor / Actuator Level Basic Types of Automation Networks • Data Network • Control Network • Device Bus / Field Bus • Sensor / Actuator Bus

43. Level 2: Hosts Recipe data downloads Production data uploads Application programming and management Level 1: Control Peer to peer data HMI displays Level 0.5: I/O I/O racks and blocks Intelligent devices Variable frequency drives Process valves Power meters Complex Sensors Level 0: Devices Pushbuttons / Simple sensors Host Level 2 Level 1 HMI Controller Peer Level 0.5 Intelligent Devices Level 0 Pusbutton Sensor Network Levels - Typical Applications

44. Level 2: Hosts Data: blocks or files Frequency: seconds to minutes Distance: LAN / WAN / Internet Level 1: Control Data: words or blocks Frequency: 50 to 500 Milliseconds Distance: 300m Level 0.5: I/O Data: bytes or words Frequency: 20 to 100 Milliseconds Distance: 300m Level 0: Devices Data: bits Frequency: 5 to 50 Milliseconds Distance: 30m Host Level 2 Level 1 HMI Controller Peer Level 0.5 Intelligent Devices Level 0 Pusbutton Sensor Network Levels - Transmission Characteristics

45. Level Network Name Information Type Data Network Information Level ( Level 2 ) Control Network Word Level ( Level 1 ) Device / Field Bus Byte & Word Level ( Level 0.5 ) Sensor/ Actuator Bus Bit Level ( Level 0 ) Ethernet TCP/IP Token ring Modbus Plus FIPWay Device NetEthernet TCP/IP Remote I/O Interbus ™ Profibus DP ™ DeviceNet ™ Lonworks ™ Fip IO ™ Lonworks ™ Seriplex ™ ASi ™ File Transfers Data Transfer Program Discrete Analog Set Points Words Discrete Limited Analog Communication Network Levels * ™ is a trade mark

46. Automation & Control System Hierarchy • Automation and control systems can incorporate them all

47. Sensor / Actuator Bus • Sensor Actuator Buses are bit level oriented

48. Sensor / Actuator Bus LONworks 16-100 ms 64 nodes 32385 500m 228 bytes High High Large Seriplex 0.7ms 64 nodes 510 1500m 1 bit Low Low Small ASi 5ms 31 nodes 31 100m 4 bits Low Low Small Speed Nodes Distance Message Size Node Cost Installed Cost Physical Size

49. ASi power supply 24 V DC Controller Network Interface Module Distribution Module Pilot Lights Actuators Valves I/O Module Push Buttons ASI Communication Network • Master - Slave Network – polled media access method • Utilizes a special 2 conductor cable for data and power • Data size - 4 bits • 31 maximum slave devices on the bus

50. 24 VDC power supply Controller / Network Interface Module Push Buttons Pilot Lights Actuators Valves Seriplex Communication Network • Master - slave or peer to peer network type • Time division media access control - 100kHz clock • Special 4 conductor cable - clock, power, data, common • Clock pulse number equals address