Live from WBF2008--Design of a Batch Process Control Tool on the PLC Platform

The presentation was authored by Giovani Godena, Igor STeiner, Janez Tancek and Marko Svetina, and presented by Steiner. The presentation content: ISA-S88.01 and Modular Batch Automation ISA-S88.01 Batch Control Tools: Configuration ISA-S88.01 Batch Control Tools: Pros&Cons PLC Batch Control: Requirements Concept of Tabular Recipes on PLC PLC Batch Control: Configuration PLC Batch Prototype: Features&Use PLC Batch Prototype: State model PLC Batch Further Concept Development ISA-S88.01 defines batch control models & terminology Separation of: Product Process Equipment Modular Batch Automation – a framework for: Flexibility Reusability Complexity management Graphical representation of recipes (SFC) A number of ISA-S88.01 based tools ISA 88.01Batch Control Tools Pros and Cons Pros: High flexibility&reusability High level of abstraction for complexity management Rich functionality Cons: Unsatisfactory reliability of the PC platform Poor adjustment to small and medium projects Unsatisfactory time behaviour of the PC platform Too low expressive power of phase behaviour model Alternative solution: Recipe execution on PLC Already used in practice Mostly oversimplified solutions Too low expressive power PLC Batch Control Requirements PC & PLC platform On PLC all real-time functions (incl. recipe execution) On PC only non-real-time functions SFC or tabular recipes representation Two levels of recipes Extended phase behaviour model Simple state propagation mechanism Portability to various PLC platforms PLC Batch Prototype Features Two-level recipes Procedure, containing Unit procedures Unit procedure, containing phases Concurrent recipes General recipes Based on Unit Classes Static Binding (on batch launching) Extended Phase Behaviour Model PLC Batch Control: Special Phases We need them for: OR branches Special recipe transition conditions Special phases are: Condition Branch (analog, digital, dialog) Jump … PLC Batch Control: Phase Logic Sequences State processing sequences: For durative states (9): Entry, Loop, Exit, Always For transient states (5): Transient Transition processing (17) Theoretical number of sequences: 58 Reduced to maximum 22 sequences Configurable to between 1 and 22 Result: customizable level of abstraction PLC Batch Control: State Propagation Propagation of holding Upwards Downwards Upper level recipes – fixed behaviour: Downwards (from procedure to unit procedure): YES Upwards (from unit procedure to procedure): NO Lower level recipes – two phase parameters: Propagation from phase to unit procedure Propagation from unit procedure to phase PLC Batch Further Concept Development Dynamic Tables Graphical (SFC) Recipes General recipes with Dynamic Binding Partner phases Parameter value deferring ……

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