Process Control and Data Acquisition SystemsOutlineDistributed Control System (DCS) ArchitectureProgrammable Logic Controller (PLC) ArchitectureSafety Instrumented Systems (SIS) ArchitectureSCADA – Supervisory Control and Data Acquisition SystemPSCC Control System ArchitectureEmerson Process Management DeltaV and OSISoft PI in PSCC – System OverviewEmerson Process Management DeltaV and OSISoft PI in PSCC – NetworkingDeltaV System – How it worksDeltaV & MD Controller – How it worksMD Controller I/O – How it worksProcess InstrumentationInput-type Field Devices – TransmittersField Junction CabinetMD Controller CabinetOutput-type Field Devices – TransducerOutput-type Field Devices – Regulatory Control ValveOutput-type Field Devices – Ball Valve w/ ActuatorDeltaV & Foundation FieldbusData Acquisition and Process Management SystemPI – Plant Information SystemSlide 23PI – How it worksSlide 251Process Control and Data Acquisition SystemsCM4120Chemical Plant OperationsJanuary 20082OutlineTypes of Control SystemsControl System Architecture for the PSCCBrief Recap of Process Instrumentation Connections to Control SystemData Archival and Retrieval System3Distributed Control System (DCS) ArchitectureUsed for continuous control of chemical processingControl functions are distributed throughout redundant, deterministic networked computer architecture–I/O interface and level 1 control functions–advanced control functions–human interfaceDCS replaced the mainframe computers of the 1970’s–non-distributed–single point of failureAdded a high level of robustness to control systemsPre-configured functionality geared toward process industries, but have a relatively high cost4Programmable Logic Controller (PLC) ArchitectureUsed for control where the devices are primarily discreteProvide very fast response (< .1 sec) to system changesTypical applications are packaging, material conveyance, and waste water treatmentVery little, if any pre-configured functionality, but PLC’s are relatively low costIn chemical processing, often are used along side DCS5Safety Instrumented Systems (SIS) ArchitectureAn over-ride control system that takes the process to a safe state when predetermined abnormal conditions occur Also called Emergency Shutdown System (ESD, ESS), Safety Shutdown System (SSD), and Safety Interlock SystemIncludes the logic control system and all the associated instrumentation including sensors, solenoids, valves, and actuatorsTypical applications are burner controls on furnaces and exothermic reactorsUsed with, but always physically separated from, process control systems6SCADA – Supervisory Control and Data Acquisition SystemScalable systems that may provide some additional level of control and data acquisition “above” the controller, DCS and/or PLC levelTypically use non-redundant TCP/IP communications and therefore are not considered appropriate for direct process controlBuilt upon non-proprietary, off-the-shelf hardwareUsed in large plants or across several plant sites where data from many sources must be collected into a single location7PSCC Control System ArchitectureWhat we have in the PSCC:Field instrumentation for measurement and final controlDCS for process control and data acquisitionUses OSIsoft PI for data archival, retrieval, process managementWindows networking and TCP/IP for communications8Emerson Process Management DeltaV and OSISoft PI in PSCC – System OverviewProPlus DeltaV server4 Operator WorkstationsMD controller w/ I/O interface cardsField instruments and interconnecting wiring systemsPI ServerDeltaV ProPlus StationPilot Plants – valves, xmittersmtu.edu NetworkPI ServerPSCCPSCCRouterRouterPSCC_DeltaVPSCC_DeltaVRedundant HubRedundant HubProfessional WorkStationsMD Controllerand I/O Cards9Emerson Process Management DeltaV and OSISoft PI in PSCC – NetworkingBusiness systems need access to data from control systems and production areasPSCC_DeltaV is a secure Control Network (green)Plant Network is local network for plant operations (red)Plant data is available to the outside thru alias “steam.we.mtu.edu”DeltaV ProPlus Stationmtu.edu NetworkPI Serveruolab-piPlant Network RouterPlant Network Routersteam.we.mtu.edusteam.we.mtu.eduPSCC_DeltaVPSCC_DeltaVRedundant HubRedundant Hub(4) Operator WorkStationsMD Controllerand I/O Cards10Control network is Windows XP Workgroup – PSCC_DeltaV, uses Windows Networking and TCP/IP protocolControl system configuration and operations graphics building are done thru ProPlus and/or Professional WorkstationsDeltaV System – How it worksProPlus station stores configuration and archives data, displays informationOperator stations archive data, display informationOperator WorkStationsPSCC_DeltaVPSCC_DeltaVRedundant HubRedundant HubProPlus StationMD Controller11DeltaV & MD Controller – How it worksPID control, discrete control, signal conversions, alarming, Fuzzy control, etc. are continuously executed by the MD controllerField instruments and final control elements are wired individually to the I/O cards in the MD controllerAlso, “networked instrumentation” available – Foundation Fieldbus, ASi bus, DeviceNet, etc.12MD Controller I/O – How it worksMD Controllerand I/O CardsPlant Area – valves, xmittersI/O cards are specific to device requirements•4-20 mA input, 4-20 mA output•24 VDC input, 24 VDC output, etc.•ASi Interface•Foundation Fieldbus Interface13Process InstrumentationInput devices used to “see” what’s going on in the processOutput devices control the processWiring systems used to connect instrumentation to the DCS14Input-type Field Devices – TransmittersWiring to field junction cabinetRTD or T/C headTemperature transmitterWiring from transmitter to temp measuring elementLevel transmitter15Field Junction CabinetSingle pairs from field devices8 pr. Cables to controller cabinet16MD Controller CabinetMD controller8 pr. cables from field junction cabinetPower-limiting Zener barriersI/O cards2nd I/O chassis17Output-type Field Devices – TransducerWire prs. to transducersCurrent to pneumatic transducersAir lines to control valves8-pr. cable from field termination cabinetSolenoids for 2-position air-actuated ball valvesAir lines to ball valvesWire prs. to solenoids18Output-type Field Devices – Regulatory Control ValveAir