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Advances in Programmable Logic Controllers, IEE Colloquium on

Date 24 Feb 1992

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Displaying Results 1 - 6 of 6
  • Advances in programmable controllers designed-in diagnostics for PLCs

    Publication Year: 1992 , Page(s): 2/1 - 2/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    The power of programmable controllers having greatly increased has given much enhanced capability but in return needs attention to program structure, status and error information automatically provided by the products and a much higher level of visibility of the condition and effectiveness of automation systems. There is continuing pressure to maximise up-time of plant, and also maintain a consistently high product quality through analysis of production tolerances and trends. Therefore the implementation of diagnostic functions within the PLC and its program for commissioning, plant operation, and maintenance is a primary concern in many industries. This is designed-in diagnostics (or D2 for short). D2 can be applied in three ways according to the facilities provided by the PLC manufacturer within the processor and its I/O structure: fault display routines; structured relay ladder programming; and the graphical program definition and structure View full abstract»

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  • IEC65B languages as a basis for open systems in PLCs?

    Publication Year: 1992 , Page(s): 1/1 - 1/9
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    The proposed IEC65B PLC (programmable logic controller) standard which covers many facets of PLC construction and usage also includes an important section on PLC programming. Four new textual and graphical programming languages are defined. This paper addresses standards that are now being developed to provide a consistent architecture and a set of languages for programming programmable logic controllers View full abstract»

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  • Integrated configuration and runtime tools for distributed control

    Publication Year: 1992 , Page(s): 6/1 - 6/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    Deals with the problem in improving the ease of use of control equipment in applications where there is a requirement for continuous evolution of the control strategy. Examples of this need arise in flexible manufacturing systems (FMS), where the deployment of a particular piece of process plant within a larger scheme will change, or where a process is being developed. An architecture which reduces the development cycle, i.e. the time it takes to implement a change to the control strategy, is needed. The procedure described requires input from systems/instrument engineers and product/process engineers View full abstract»

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  • Achieving traceability in PLC software

    Publication Year: 1992 , Page(s): 3/1 - 3/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    To reduce the risk of latent errors software development must be carried out using quality assurance procedures and applying the concept of traceability. It should be possible to show how the needs of the user have been satisfied, that the software is free of unwanted functions, and the design is complete. The history of modifications or errors should be recorded to show where changes have affected the design. The programmable controller manufacturers are supplying PC based computer aided software engineering tools working with Windows. This provides the framework for drawing up a quality plan and establishing traceability links View full abstract»

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  • Integration of PLCs with mobile information terminals

    Publication Year: 1992 , Page(s): 4/1 - 4/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    The information that can be collected and processed by PLCs, must then be passed on to staff in some form so that the information can be used, or reacted to, as required. Integration of a PLC system with a mobile information terminal (a small digital radio receiver) system offers real time information flow to people who are mobile, which results in increased efficiency through decreased response time, and decreased machine or plant down time. Integration of these two technologies is a reasonably simple task, usually only requiring a little software in the PLC View full abstract»

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  • PLC control systems for the remote control of cranes and manipulators

    Publication Year: 1992 , Page(s): 5/1 - 5/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    The currently under construction and nearing completion nuclear reprocessing plants, the Thermal Oxide Reprocessing Plant (THORP) at Sellafield in Cumbria, is divided into two main plant areas, the head end and chemical separation facility. Within the head end and chemical separation facility are two virtually identical areas known as the north and south filter caves. All contaminated air from within the THORP ventilation system is routed to these filter caves. The control system described is responsible for filter change and all other `in-cave' activities. Within the filter cave is an electrically driven overhead travelling crane (EOTC) a carriage, a 2 tonne auxiliary hoist, a 500 kg telescopic mast, a powered grab and a 70 kg articulated power manipulator arm. Two independent PLC's are used, the first controlling and monitoring the EOTC, hoist, telegrab and manipulator and the second to control and monitor shield doors, gamma gate, bogie and delidder View full abstract»

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