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DESY SCADA Experience. Matthias Clausen DESY/ MKS-2. Overview. What is SCADA (compared with DCS systems) Where and Why are SCADA systems used What do SCADA systems Provide? Evolution OPC for SCADA Benefits Experience from DESY Outlook. S upervisory. D ata. A cquisition. C ontrol.
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DESY SCADAExperience Matthias Clausen DESY/ MKS-2 EPICS Workshop - Oak Ridge
Overview • What is SCADA (compared with DCS systems) • Where and Why are SCADA systems used • What do SCADA systems Provide? • Evolution • OPC for SCADA • Benefits • Experience from DESY • Outlook EPICS Workshop - Oak Ridge
Supervisory Data Acquisition Control Distributed database Data Server Data Server PLC’s Field Bus ERP Systems Expert Systems SCADA ? SCADA ? SCADA ? And Archiving, Logging, Access Control, Alarms Graphics and Batch processing Control Programs EPICS Workshop - Oak Ridge
What, Where and Why • What is “SCADA”and where is it used • Supervisory Controls And Data Acquisition • Application area : • Industrial processes: chemical, power generation and distribution, metallurgy, … • Nuclear processes: reactors, nuclear waste, ... • Experimental physics: Tokamaks, HEP laboratories • Application size: • 20 K I/O to 450 K I/O, two examples of 1 M I/O under development • Why SCADA systems were evaluated for LHC SLC ? • Reduction of resources • CERN policy of “outsourcing” EPICS Workshop - Oak Ridge
What do SCADA Provide? • Flexible and open architecture • Basic SCADA functionality • MMI • Alarm Handling and Trending • Access Control • Automation • Logging, Archiving, Report Generation • Interfaces to H/W and S/W • Interfaces to ERP- and Expert-Systems • Development Tools EPICS Workshop - Oak Ridge
Generic Software Architecture SCADA Developt. Environt. SCADA Client Graphics Editor Active X Controls MMI Tren- ding Alarm Display Log Display ASCII File Editor Active X Container Library Client / Server - Publish / Subscribe - TCP/ IP ASCII Files SCADA Server Recipe DB RT & Event Manager Export / Import Data Proces Report Gener. Alarm Log Archive Recipe Managt Commercial DB RT DB SQL Alarm DB Log DB Archive DB Ref. DB Project Editor ODBC Commercial Devel. tool Data R/W DDE Driver Toolkit API/DLL Private Application EXCEL Driver OPC VME PLC PLC EPICS Workshop - Oak Ridge
SCADA functions • Logging, Archiving • Data stored in compressed and proprietary format • Logging / Archiving either for a set number of parameters or for a set period of time • Logging / Archiving can be frequency or event driven * • Logging of user actions together with a user ID • VCR facility for playback of stored data • Writing logs into RDB • Report Generation • Reports created using SQL type queries to the RTDB or logs • Automatic generation, printing and archiving of reports • Use of ‘components’ for report generation * ! Experience @ DESY EPICS Workshop - Oak Ridge
Interfaces to H/W and S/W • H/W • Multiple communication protocols supported in a single system (in particular CERN supported Field busses) • Support for major PLCs/DCSs but not VME • S/W • API • ODBC, DDE and OLE I/F to PC Products • OPC Client and OPC Server • ActiveX Containers • Web clients EPICS Workshop - Oak Ridge
Development Tools • Project editor • Graphics editor • Configuration through parameter templates • Scripting language • Most processing tools based on IEC 1131 • Batch configuration according to S88.1 • Driver Development Tool Kit EPICS Workshop - Oak Ridge
Benefits of SCADA • Standard frame for application • Rich functionality (50 - 100 p-yrs investment) • Reliability and Robustness (very large installed base, mission critical processes) • Limited specific development • Technical support and maintenance • ….. Etc Enough arguments for the management to promote SCADA systems. EPICS Workshop - Oak Ridge
Benefits? – not only • Namespace: flat vs. OO • System Load • Network • Processor • Project Management More Aspects to take into Account: • Configuration of SCADA Systems • Data Access Mechanism’s DESY Experience: EPICS Workshop - Oak Ridge
Data Server Data Server PLC’s Field Bus Configuration of SCADA Systems Different Namespaces!! EPICS Workshop - Oak Ridge
Configuration of SCADA Systems 2nd PLC SCADA Communication Processor Programs • Analog-Input • Value-AI-0 • Value-AI-1 • Analog-Output • Value-AO-0 • Value-AO-1 • Analog-Input • Vacuum_VALUE • Pressure_VALUE • Analog-Output • Valve_1_OUT • Heater_1_OUT Mapping Field Bus EPICS Workshop - Oak Ridge
Configuration of SCADA Systems 3rd(Alarms) SCADA Data Server Alarm Generation • (generic) Alarm scripts: • IF (Pressure_VALUE > Pressure_HIHI_ALARMVAL) • {Pressure_ALARM_HIHI=TRUE • Pressure_ALARM_STATE=CRITICAL • Pressure_ALARM_COLOR=RED } • IF (Pressure_VALUE < Pressure_LOLO_ALARMVAL) • {Pressure_ALARM_LOLO=TRUE • Pressure_ALARM_STATE=ATTETION • Pressure_ALARM_COLOR=BLUE } • Analog-Input • Vacuum_VALUE • Pressure_VALUE • Analog-Output • Valve_1_OUT • Heater_1_OUT EPICS Workshop - Oak Ridge
The burden of flat namespaces: ... A lot of individual tags! 17 10 10 8 4 • Vacuum_VALUE • Pressure_VALUE • Valve_1_OUT • Heater_1_OUT Pressure_VALUE Pressure_HIHI_ALARMVAL Pressure_ALARM_HIHI Pressure_ALARM_STATE Pressure_ALARM_COLOR Pressure_VALUE Pressure_LOLO_ALARMVAL Pressure_ALARM_LOLO Pressure_ALARM_STATE Pressure_ALARM_COLOR 4 4 2 EPICS Workshop - Oak Ridge
Data Access Mechanism's Alarm Server • Alarm Server typically poll data from the data server ( -> impact on network bandwidth) More advanced techniques like publish / subscribe are available in some cases • Data from field buses are mainly polled Asynchronous protocols are difficult to handle Data Server Polling Polling Field Bus EPICS Workshop - Oak Ridge
DESY Experience 1st • Namespace • Individual tags for each property blow up the namespace • Flat namespaces of thousands of tags can not be properly handled without adequate tools • Latest SCADA technology clearly shows the trend to support the definition of objects which cleans up the namespace • System Load • Additional –non standard- features like • calculating alarms for each channel • temperature conversions ( 6th grade polynomial) ... can cause a lot of overhead which needs to be taken into account for the calculation of the system load on process controllers ( here: in a SCADA-like DCS system) EPICS Workshop - Oak Ridge
DESY Experience 2nd • Project Management • Small systems can be easily handled with in-house personal • Big systems (several thousand of channels) should be coordinated by an engineering office because of: • The coordination of the Field Bus (PLC) databases and the SCADA databases • The knowledge of the various tools which come along with a SCADA system • One of the main arguments for SCADA systems is: outsourcing EPICS Workshop - Oak Ridge
DESY Experience 3rd • The SCADA project at DESY failed: • The project management of the company underestimated the necessary time to perform the engineering of the project. • The company underestimated the overhead for temperature conversions and the required calculations for alarm checking • As a result – the front end processors were not capable to handle the I/O and the calculations in the specified rate EPICS Workshop - Oak Ridge
Preliminary conclusions • DCS system requirements are different from SCADA requirements • More frond end functionality • More record or device oriented configuration • System wide configuration tools are needed • Water tight specifications are necessary • DCS systems are more expensive than SCADA systems • A call for tender has to focus on either DCS or SCADA • SCADA systems are less expensive, but they offer different functionality • SCADA and DCS (mixed) can not selected by price EPICS Workshop - Oak Ridge
SCADA @ DESY • Utility controls @ DESY use EPICS as a SCADA system • H1 is going to use PVSS for their slow controls • For TESLA a lot of components will be delivered by industry: • Various subsystems can be controlled by SCADA systems: • Utility Controls (water, energy, air, heating...) • Cryogenic Controls (cryogenic plants, cryogenic distribution) • Vacuum Systems (insulation vacuum, beam vacuum) • Problem: Integration of SCADA systems into accelerator controls EPICS Workshop - Oak Ridge
That’s all Folks EPICS Workshop - Oak Ridge