Mitsubhishi company has developed a new PLC compact controller system called FX3U, which is a high performance compact PLC with upto 384 control points, and adds greater flexibility and increased performance to the sy...
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Mitsubhishi company has developed a new PLC compact controller system called FX3U, which is a high performance compact PLC with upto 384 control points, and adds greater flexibility and increased performance to the system. Various features of the system include flexibility due to application-specific special function modules, integrated real-time clock, and internal PID controller with autotuning. The brand has remained one of constant quality, reliability, innovation, and versatility to remain ahead of others in the market. The company has sold six million units of the system in every country of the world in the last 25 years. Analog adapters include those for voltage/current input, voltage-current output, PT100 input and thermocouple input.
The importance of programmable logic controllers (PLCs) in improving the information flow is discussed. PLCs have become smaller, cheaper and easier to use and can now provide motion control, interface with vision sys...
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The importance of programmable logic controllers (PLCs) in improving the information flow is discussed. PLCs have become smaller, cheaper and easier to use and can now provide motion control, interface with vision systems, and link to enterprise networks. PLCs are also called programmable automation controllers (PACs), that provide fully configurable I/O, motion control, human-machine interface (HMI) support, and direct device-to-enterprise connectivity. Engineers can monitor, control and program the PAC via Internet browsers and enterprise servers and the device can be controlled for various applications through six internal module bays. Besides this, the devices are also managing the assembly line.
The control of accurate axle position is discussed in this paper. The pulse output function and highspeed count function of PLC (programmablelogical Controller) are used to realize the purpose of the study. The main ...
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The control of accurate axle position is discussed in this paper. The pulse output function and highspeed count function of PLC (programmablelogical Controller) are used to realize the purpose of the study. The main principle of this control and its practical application are discussed. The systematic composition of such control system model is given. Several key problems are discussed. The principle obtained in this study has got very good application in the real work. The usage of this principle in automatic equipment controlling or in transformation from manual equipment to automatic ones has certain theoretical and actual directive significance.
The paper describes a modeling approach that aims to provide a unified framework for the specification and verification of logiccontrollers for multi-domain physical systems. The proposed modeling methodology is base...
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ISBN:
(纸本)0780395670
The paper describes a modeling approach that aims to provide a unified framework for the specification and verification of logiccontrollers for multi-domain physical systems. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows to describe both control software and physical components using the same basic concepts, like classes and interface ports, and the same modeling notation, based on the UML language. Thanks to this unified approach, it is possible to describe structural and behavioral aspects of any multi-domain system coupled with a logic control device. Moreover, the behavior of the closed-loop system can be analyzed with formal verification techniques for hybrid systems, in order to prove correctness properties otherwise difficult to verify considering only discrete-event models.
programmable logic controllers (PLCs) are a key component of modern industrial automation installations. Nowadays there is an increasing trend to integrate them in enterprise networks, for accessing real time producti...
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Functional safety, as addressed in the standard IEC 61508, is a key requirement for a high dependability of controlled systems. in order to guarantee that the function of programmable logic controllers (PLC) complies ...
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The transition between the supervisory control theory (SCT) and its implementation in programmable logic controllers (PLCs) is not straightforward. This is mainly due to the fact that the SCT is stated in an event-bas...
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The transition between the supervisory control theory (SCT) and its implementation in programmable logic controllers (PLCs) is not straightforward. This is mainly due to the fact that the SCT is stated in an event-based asynchronous setting whilst PLCs are signal-based, synchronous and sequential. Based on Petri nets, the PLC programming language sequential function chart (SFC) seems to be the ideal choice for this transition. However, the transition requires detailed knowledge of how the PLC and SFCs work. Different execution models for SFCs are presented and compared with the international standard IEC 61131-3. Often, the application of the SCT to a control problem results in a set of modules between which mutual exclusion and synchronisation are important aspects. The results indicate, however, that for modular SFC programs it seems generally impossible to simultaneously achieve both mutual exclusion between modules as well as synchronisation of modules without using workarounds that may be either manual or suffer from state space explosion. Nevertheless, one of the presented execution models, the immediate transit/ immediate action model, together with a handshaking procedure is shown to give a simple solution to both mutual exclusion and synchronisation. (c) 2004 Elsevier Ltd. All rights reserved.
This paper presents a systematic approach for the design and implementation of the sequence controller in manufacturing systems. By employing the IDEF0, we construct the simplified Petri net controller (SPNC) through ...
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This paper presents a systematic approach for the design and implementation of the sequence controller in manufacturing systems. By employing the IDEF0, we construct the simplified Petri net controller (SPNC) through the material flow diagram and the information flow diagram. Then, the ladder logic diagram (LLD) can be transformed from the SPNC through the token passing logic (TPL). The proposed approach, including the IDEF0, SPNC, and TPL tools, leads to the standard IEC1131-3 LLD for PLC implementation. Finally, an application of a stamping process is provided to illustrate the design procedure of the developed approach.
One area where discrete event systems are currently used is the design of control systems based on programmable logic controllers (PLCs). As the PLC technology is evolving into a family of control functions of many ty...
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One area where discrete event systems are currently used is the design of control systems based on programmable logic controllers (PLCs). As the PLC technology is evolving into a family of control functions of many types at many different levels of complexity, there is an increasing need for software tools providing the systematic development of real industrial applications including modeling and control of discrete event systems. This paper describes the use of a state-diagram method in the computer aided logical synthesis and design of automation circuits. It also presents the corresponding software package developed for control logic creation. The developed software generates control logic in the form of Ladder electric circuits since they present descriptive simplicity and are widely known in the PLCs' world. The developed software package is also suitable for both industrial practice and teaching purposes. (c) 2004 Elsevier Ltd. All rights reserved.
The introduction of programmable automation controller (PAC), a new generation of industrial controllers that combine the functionality of a programmablelogic controller (PLC) and a PC, is discussed. PAC that incorpo...
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The introduction of programmable automation controller (PAC), a new generation of industrial controllers that combine the functionality of a programmablelogic controller (PLC) and a PC, is discussed. PAC that incorporate vision or high speed measurements with logic and motion control eliminate the need for engineers to integrate dissimilar hardware and software platforms. Some PAC can directly take high accuracy measurements at hundreds of thousands of samples per second, allowing engineers to pull data directly into their control systems. Common applications include part inspection for manufacturing or assembly verification, such as checking for correct component placement on a circuit board.
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