A market leader in modular concrete block manufacturing systems is using the most flexible approach yet to meet safety requirements: freely programmable, failsafe PLC technology in combination with standard field bus ...
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A market leader in modular concrete block manufacturing systems is using the most flexible approach yet to meet safety requirements: freely programmable, failsafe PLC technology in combination with standard field bus engineering. This approach makes it possible to meet standards and regulations swiftly and with individualized solutions during any given expansion phase.
Recent developments in programmablelogic controller (PLC) hardware and software have increased the range of motion applications that these devices can control. These developments have also placed the PLC in strong co...
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Recent developments in programmablelogic controller (PLC) hardware and software have increased the range of motion applications that these devices can control. These developments have also placed the PLC in strong competition with personal computers in these same applications. Considerations must be given to the choice of computer hardware, computer software and computer networks.
Human-machine interfaces (HMIs) have come a long way since their inception in the 1980s as computers became more prevalent in manufacturing, and today's optimized plants deserve optimized HMI designs. HMIs were de...
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Human-machine interfaces (HMIs) have come a long way since their inception in the 1980s as computers became more prevalent in manufacturing, and today's optimized plants deserve optimized HMI designs. HMIs were developed so that humans could interact with the programmable logic controllers (PLCs) introduced in the 1970s to replace hard- wired relay logic.
Programming language choices for programmable logic controllers (PLCs) are many. It is said the great thing about standards is there are so many to choose from! While this is meant as sarcasm, in the case of IEC 61131...
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Programming language choices for programmable logic controllers (PLCs) are many. It is said the great thing about standards is there are so many to choose from! While this is meant as sarcasm, in the case of IEC 61131-3 Programming Languages, it is an advantage to have several language standards from which to choose.
As PLC (programmablelogic controller) become smaller and smarter and devices with more and more intelligence are interconnected on the factory floor and in the control room, issues such as data security will become i...
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As PLC (programmablelogic controller) become smaller and smarter and devices with more and more intelligence are interconnected on the factory floor and in the control room, issues such as data security will become increasingly important. However, ways will be found to use the strong points of existing technology and solution will be sought for problems as yet anticipated. Clearly, the complex relationship between human and computer is emerging.
The Generalized Predictive Controller (GPC) belongs to the general class of predictive controllers. The authors have proposed an alternative (although equivalent) formulation for the GPC in state space. This formulati...
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The Generalized Predictive Controller (GPC) belongs to the general class of predictive controllers. The authors have proposed an alternative (although equivalent) formulation for the GPC in state space. This formulation is based on a robust observer, and the poles selection is closely related to the controller robustness. An important feature of predictive controllers consists of their ability to take explicitly into account hard constraints in their formulation. However, their design must be accompanied by a guarantee of feasibility. There are some papers which deal with this problem, although all of them suppose that the state of the process can be measured on-line. However, in some cases, the design of the GPC proposed by the authors cannot measure online the process states since they are artificial states, that is to say, not related to physical magnitudes. The authors in paper extend the results of to the GPC in the case where all the states are online measurable. So the state estimation will be presented employing the same ideas of this previous work. When the states have to be observed with the robust observer proposed, the authors show that there appears in the analysis a linear but time varying system perturbed with the error in the initial estimation of states. This initial error belongs to a known and bounded set. The main result states that if it is possible to find a collection of non-empty sets Kj that converge to the maximal robust control invariant set when j increases, the feasibility of GPC control law is guaranteed for all the sampling instants. Finally, this result is verified in a numerical example with a 2 states process.
According to the technology requirements of measurement for animal casing, in this paper, we use PLC and touch screen as the control core, the electromechanical integration design ideas to research the methods and pri...
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Electrohydraulic proportional directional valves provide an easy, cost-effective way to eliminate damaging shock and vibration in a hydraulic system. Such control valves respond to discrete signals from the programmab...
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Electrohydraulic proportional directional valves provide an easy, cost-effective way to eliminate damaging shock and vibration in a hydraulic system. Such control valves respond to discrete signals from the programmable controller, allowing the machine designer to create an open-loop motion profile without the use of an analog output module or dedicated motion controller. The user is able to adjust the dynamic parameters of the motion profile on the valve itself. Other features and benefits include some method of program storage, automatic deadbands, linear ramps, and diagnostics. The two application areas of turret lathe and vertical head machining center are discussed.
programmablelogic arrays (PLAs) are widely used in VLSI systems because of their compactness, ease of automatic design, and regularity in their structure. This paper presents an innovative method for on-chip testing ...
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programmablelogic arrays (PLAs) are widely used in VLSI systems because of their compactness, ease of automatic design, and regularity in their structure. This paper presents an innovative method for on-chip testing of embedded PLAs which makes use of the input/output registers as test aids. Experimental results on the implementation of a real self-testing PLA are given in order to show the effectiveness of our approach.
The main objective of this paper is to present a working solution for measuring data from a sensor array via a PLC and simultaneously controlling a set of actuators by the means of a Labview application. A demo box wa...
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The main objective of this paper is to present a working solution for measuring data from a sensor array via a PLC and simultaneously controlling a set of actuators by the means of a Labview application. A demo box was developed in order to test the communication protocol and finally to simulate a closed loop control for a slow system.
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