Web based supervisory control and data acquisition Thomas Dreyer (RACOS) David Leal (CAESAR Systems) Andrea Schröder (FGH) Michael Schwan (FGH) 2 nd International Semantic Web Conference, October 2003

2 GbR mbH © ScadaOnWeb Project data Project-acronym: ScadaOnWeb Project-title: Web based supervisory control and data acquisition Sponsors: EC and BBW in the Information Society Technologies (IST) programmes Project start: 1st September 2001 Project duration: 2 years Partners: 7 Project manager:FGH

3 GbR mbH © ScadaOnWeb Project partners Caesar - Caesar Systems Limited Cygnus - Cygnus Engineering AG Bacher - Bacher Consulting LABEIN - Fundacion Labein SEfAS - Sintef Energy Research FGH - Forschungsgemeinschaft für Elektrische Anlagen und Stromwirtschaft e.V. RACOS - Racos Technische Informationssysteme

4 GbR mbH © Our objective  To put SCADA data on the web  So that SCADA data can be handled by cheap software  Low cost applications for which dedicated SCADA systems are not affordable  The opportunity  A semantically precise SCADA object  Open source software to access it defined by the project written by the project   Validated by project demonstrators

5 GbR mbH © Requirements for the technology  SCADA systems are different because they handle large amounts of data - gigabytes  The data is structured into arrays of different dimensions  for each time point there is a 1D array of 1000 measurements  time points gives a 2D array (10000  1000)  Efficiency requires  maintenance of the array structures - no ‘confetti’ data  numbers held as binary format  Use over the web requires  XML for the semantics of the data  ontologies for the measurement process - e.g. sampling rates  ontologies for physical properties, physical quantities and units  ontologies for measurement quality

6 GbR mbH © variables Structured semantic data block positions states/times semantics gigabytes of structured data extract and download subsets acknowledgements to

7 GbR mbH © OWL What we defined system definition property ontology measurement quality ontology units ontology self describing measurement object compact binary data block full semantics measurement quality HDF5 binary data OWL semantic wrapper

8 GbR mbH © HDF5 (Hierarchical Data Format - version 5)  Standard for the exchange of structured binary datasets  developed by NCSA  used for NASA and ESA for satellite telemetry  used for oil exploration data  Exchange of binary data between computers  access library availably on many different types  callable from C, Fortran, and Java  Range of tools for  data addition and extraction;  display and editing  interface to and from XML  But the HDF5 tools do not know about the meaning of the data

9 GbR mbH © Demonstrators  Flood warning system based upon many remote sensors  Flexible metering of domestic and small industrial consumers  Data sharing within a balance group in the energy market  Control of distributed wind and hydro electricity generation  Condition based maintenance of remote equipment

10 GbR mbH © Brig, Switzerland, September 23, 1993 © C. Heinen, 1993

11 GbR mbH © © G. Escher 1993 Brig, Switzerland, September 1993

12 GbR mbH © Proposed MacEco Web interface

13 GbR mbH © Different presentations - graphs 3 different weeks 3 different mondays

14 GbR mbH © Wind park main display

15 GbR mbH © Wind mill

16 GbR mbH © Monitoring data of transformers Failure rates of transformers with tap changers: (CIGRE failure statistic)

17 GbR mbH © Fundamentals of the technology  Formal approach to engineering data  based upon ISO  a design is a Class  Physical property, quantity and scale  a physical quantity is a member of a physical quantity space  a physical quantity space is the domain of a scale  Product, activity and state  4D world view  Measurement quality  quality is a measurement of the measurement system  Distribution  a distribution is a Property  Descriptions of a distribution  described by a numerical table  stored as HDF5

Engineering use of classes

19 GbR mbH © Designs are classes crankshaft V6 crankshaft Rover 75 crankshaft Rover 75 crankshaft rev1.2 rotating part engine part machined-surface part unmachined-surface part part with oil holes cast iron SG cast iron crankshaft SG cast iron SG cast iron grade XYZ

20 GbR mbH © ‘Members’ of a design Rover 75 crankshaft rev1.2 The crankshaft in test T_1234 member of class

21 GbR mbH © Definition of design classes length in range 9.99 to m material S_1234 XYZ_123

Physical property, quantity and scale

23 GbR mbH © Physical quantity as a class The class called “10 Kg” has instants in the lives of material objects as members. An instant in the life of a material object is a member if and only if it has 10 times the same inertial mass as the reference lump of platinum in Paris. But usually it is more complicated: Vessel Mass massWhenEmpty Physical property Physical objectPhysical quantity

24 GbR mbH © Getting units right Mass Real kg A unit or scale is a Property of a physical quantity. 10.0

25 GbR mbH © Getting units right Mass Real kg A unit or scale is a Property of a physical quantity. Vessel massWhenEmpty 10.0 </massWhenEmpty

Measurement quality

27 GbR mbH © A measurement system at an instant physical system measurement system partOf physical system at instant measurement system at instant partOf instantOf measured property measured system quality

28 GbR mbH © IEC Measurement quality Validity DetailQual Source TestStatus OperatorBlockedStatus OverflowStatus OutOfRangeStatus BadReferenceStatus OscillatoryStatus FailureStatus OldDataStatus InconsistencyStatus GoodQuestionableInvalid Overflow NotOverflow OutOfRange NotOutOfRange BadReference NotBadReference Oscillatory NotOscillatory Failure NotFailure OldData NotOldData Inconsistent NotInconsistent Process Default Substituted TestNotTest OperatorBlocked NotOperatorBlocked SpaceAllowed values

29 GbR mbH © Temperature, time and validity the temperature the time the validity

4D modelling

31 GbR mbH © Things in the real world space time Product Product Life Segment (activity) Product At Instant (state) its identifier what type it is how it is connected when: from --> to maximum flow rate total flow average flow rate when: at flow rate at instant

32 GbR mbH © Distributions time flow rate sampling decomposition time total flow in period

Property distributions with respect to space and time

34 GbR mbH © Array of sensors at an instant temperature For each sensor at an instant in the set there is a temperature my sensor at instant set temperature my distribution sensor at instant measuredTemperature subclasssubproperty

35 GbR mbH © Array of sensors at an instant temperature For each sensor at instant in the set there is a temperature and quality my sensor at instant set temperature and quality space my distribution For each integer there is a real and quality identifier 1 to20 real and integer vector array parameterisation: numbering of the sensors scale: Celsius and representation of quality by an integer vector

36 GbR mbH © Semantics and mathematical description HDF5 XML domain of distribution physical quantitydistribution (field) maths space maths function parameterisation scale: units coordinate system description product (instrument) sampling or decomposition

37 GbR mbH © Structured data block variables positions states/times semantics gigabytes of structured data extract and download subsets acknowledgements to

38 GbR mbH © External reference to HDF the property the object that has it the data order the data the units the data

Conclusions

40 GbR mbH © properties (ISO 15926) SCADA ISO maths ScadaOnWeb Ontologies OWL (with RDF and RDFS) physical object decomposition and sampling distribution and description physical quantity spaces SI units time IEC quality structure number and text W3C physical property quantity and scale demonstrator ontologies

41 GbR mbH © Next steps  Automated decision making  Now – predefined alert ( or txt message) template implemented by explicit code  Future – alert criteria defined by a rule base  Make the semantic measurement object stick as an industry standard  Publication of measurement ontologies as annexes to existing ISO/IEC standards  Process industry – links to ISO (Life cycle data for process plant)  Electricity transmission grid control standards  National energy management standards  Open source semantic measurement software

42 GbR mbH © Flood warning demonstrator  prototype

Questions