The FPO micro programmable controller (PLC) from Aromat Corp. is featured. Features of the microPLC include floating point math;two-axis positioning with pulse or pulse width modulation output to 10kHz;four high-speed...
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The FPO micro programmable controller (PLC) from Aromat Corp. is featured. Features of the microPLC include floating point math;two-axis positioning with pulse or pulse width modulation output to 10kHz;four high-speed counters;trapezoidal motion profile;5K words of program memory;seven hardware interrupts;and 0.9 microsec/step scan rate. One unique programming feature of the PLC is the ability to edit the program while it is executing. Contact information and price are given.
Flexible manufacturing cells (FMCs) are well established as a means of improving manufacturing efficiency in many batch production industries. They consist of an integrated group of computer numerically controlled (CN...
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Flexible manufacturing cells (FMCs) are well established as a means of improving manufacturing efficiency in many batch production industries. They consist of an integrated group of computer numerically controlled (CNC) machine tools, programmable logic controller (PLC) based work/tool handling equipment and a control system to synchronize their operation. The safe and reliable operation of FMCs is clearly essential for their efficient use. However, FMCs are complex systems with elements that operate concurrently and interact at irregular times, depending upon the components to be produced. This inherent complexity demands intricate and sophisticated control systems which require development methodologies that are both comprehensive and rigorous. In this paper the authors introduce a methodology (PN ↔ PLC) which uses Petri nets for producing correct programmable logic controller (PLC) programs directly from the specifications. The methodology is specifically contrasted with the benefits, and problems, encountered in using tools such as 'ladder diagrams' (LDs) and 'sequential function charts' (SFCs) for designing logical control systems. PN ↔ PLC has advantages over ladder logic in clarity, which allows the program to be checked, maintained and updated reliably. Furthermore, the Petri net graph is a one-to-one equivalent of a ladder logic diagram, and thus either representation may be algorithmically translated to the other without loss of information. Finally, the rules for creating Petri net graphs, and subsequently translating them, are both simple and robust in use. [ABSTRACT FROM AUTHOR]
The industrial world lacks common models for the design and realization of distributed industrial-process measurement and control systems. The different models and approaches originate from private solutions of differ...
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The industrial world lacks common models for the design and realization of distributed industrial-process measurement and control systems. The different models and approaches originate from private solutions of different vendors of control equipment aimed at different customers. An approach for distributed control blocks is introduced and refined, which describes distributed control systems, hierarchical control systems, and agent systems. Since this model is currently under standardization in the International Electrotechnical Commission, widespread use can be expected and further contributions from research institutes will be helpful.
In this paper, a new gain self-tuning method for PI controllers based on a fuzzy inference mechanism has been proposed and implemented. The essential idea is: (1) define a dynamically changed reference trajectory in t...
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In this paper, a new gain self-tuning method for PI controllers based on a fuzzy inference mechanism has been proposed and implemented. The essential idea is: (1) define a dynamically changed reference trajectory in the error and error derivative plane, called a 'sliding trajectory';(2) compute the error area between the sliding trajectory and the effective one with a special algorithm, and use this quantity as a performance index to evaluate the system response;(3) draw a fuzzy relationship between a PI gain correction parameter and the performance index;(4) based on the fuzzy inference mechanism, PI gains are calculated and tuned. The proposed method has been verified through simulations, using the speed control of a PM synchronous motor drive system as a testbed. The results obtained demonstrate the effectiveness of this novel method.
Guidelines developed by the SEMSPLC Project, a DTT/EPSRC sponsored project, are being published by the IEE. The SEMSPLC Guidelines provide industry with a software engineering method which is suitable for use in the d...
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Guidelines developed by the SEMSPLC Project, a DTT/EPSRC sponsored project, are being published by the IEE. The SEMSPLC Guidelines provide industry with a software engineering method which is suitable for use in the development of safety-related PLC application software and is a PLC specific implementation of IEC 1508.
Verification method has been developed for determining the safety and operability of programmable logic controller (PLC) based systems. The method automatically checks sequential logic embedded in PLCs and provides co...
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Verification method has been developed for determining the safety and operability of programmable logic controller (PLC) based systems. The method automatically checks sequential logic embedded in PLCs and provides counterexamples if it finds errors. The method consists of a system model, assertions, and a model checker. The model is a Boolean-based representation of a PLC's behavior. Assertions are questions about the behavior of the system, expressed in temporal logic. The model checker generates a state space based on the above two inputs, searches the space efficiently, determines the consistency of the model and assertions, and supplies counterexamples. A modeling technique has been developed to verify relay ladder logic (RLL), a PLC programming language. The performance of the model checker is studied in a series of alarm designs
The purpose of this paper is to present a programmable logic controller (PLC) control system that is applied to the main feedwater process of a pressurized water reactor, construct a structure that the alternative sys...
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ISBN:
(纸本)0780335457
The purpose of this paper is to present a programmable logic controller (PLC) control system that is applied to the main feedwater process of a pressurized water reactor, construct a structure that the alternative system is a hot backup to the operating system between PLC and the original analog instrument control system, overcome the draw backs of TI545 type PLC control module, and implement an advanced digital control algorithm to improve the control performance simultaneously. Successful results are obtained from this scheme. Implementation indicates that the PLC control system improves the performance of both steam generator water levels regulation and disturbance rejection.
BridgeVIEW, National Instruments' new data acquisition and control (DAC) and man-machine interface (MMI) software, leverages LabVIEW's graphical programming environment and provides additional tools for SCADA ...
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BridgeVIEW, National Instruments' new data acquisition and control (DAC) and man-machine interface (MMI) software, leverages LabVIEW's graphical programming environment and provides additional tools for SCADA functions. The software is specifically addressed to the needs of users in manufacturing and process control. BridgeVIEW, which runs on Microsoft Windows 95 and Windows NT, is designed to monitor and control one or more distributed units in a client-server architecture. With BridgeVIEW, users can monitor the process, change setpoints and send control instructions to individual data acquisition devices.
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