Numerical testing of microcontrollers is a reasonable way to design their parameters in a consistent environment. Indeed, in such a way, one avoids unrepairable failures of the device to be controlled and the conseque...
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By integrating the MPM (multi package module) and flip chip (FC) technologies together, the MPM-FCBGA package can increase performance and allow miniaturization. This also offers a lower-cost solution for customers wh...
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programmable logic controllers, PLCs, have become the industry standard, replacing the hard-wired electromechanical devices, in controlling process machines and driving the equipment of manufacturing. Varying in size ...
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programmable logic controllers, PLCs, have become the industry standard, replacing the hard-wired electromechanical devices, in controlling process machines and driving the equipment of manufacturing. Varying in size and sophistication, these electronic devices are now produced by over 50 manufacturers. In our 2 and 4 credit-hours courses for manufacturing and electronic engineering technology students, relay circuits, fundamentals of sensors, and electrical controls are explained first. Then, the PLCs, from hardware structures, installation, wiring, to ladder logic programming are elucidated. Experience in teaching two different groups of students with different academic background and preparation are presented. Approaches taken in each class are discussed.
The Tracker is one of the CMS (Compact Muon Solenoid experiment) subdetectors to be installed at the LHC (Large Hadron Collider) accelerator, scheduled to start data taking in 2007 at CERN (European Organization for N...
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ISBN:
(纸本)0889863725
The Tracker is one of the CMS (Compact Muon Solenoid experiment) subdetectors to be installed at the LHC (Large Hadron Collider) accelerator, scheduled to start data taking in 2007 at CERN (European Organization for Nuclear Research). The tracker will be operated at a temperature of -10°C in order to reduce the radiation damage on the silicon detectors;hence, an insulated environment has to be provided by means of a screen that introduces a thermal separation between the Tracker and the neighboring detection systems. The control system design includes a formal description of the process by means of a thermodynamic model;then, the electrical equivalence is derived. The transfer function is inferred by the ratio of the voltage on the outer skin and the voltage input, i.e. the ratio of the temperature outside the tracker and the heat generated (which is the controlled variable). A PID (Proportional Integral Derivative) controller has been designed using MatLab. The results achieved so far prove that this methodology is rigorous, effective and time saving;every step of the procedure is well defined, simplifying the debugging and updating. Besides, the first field tests show a good accordance of the model to the real system.
Formal modeling and verification of a control algorithm allow to derive a correct and fault tolerant controller. In this contribution the combination of Signal Interpreted Petri Nets (SIPN) as formal model and symboli...
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For the lower Safety Integrity Levels, SIL1 and SIL2, as defined by the functional safety standards ANSI/ISA 84.01 [1], IEC 61508 [2], and process industry specific draft IEC 61511 [3], many end-users / operating comp...
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ISBN:
(纸本)1556178433
For the lower Safety Integrity Levels, SIL1 and SIL2, as defined by the functional safety standards ANSI/ISA 84.01 [1], IEC 61508 [2], and process industry specific draft IEC 61511 [3], many end-users / operating companies tend to focus on the use of a General Purpose PLC instead of a Safety PLC as the logic solver in their Safety Instrumented Functions. In order to improve the reliability of the General Purpose PLC, the use of a Hot-Standby PLC is often suggested. This paper will describe the advantages and disadvantages of a Hot-Standby General Purpose PLC when compared to a General Purpose PLC, simplex Safety PLC, and ultimately a fully redundant Safety PLC. The difference in system behavior for a General Purpose PLC, a Hot-Standby PLC, and the simplex or fully redundant Safety PLC will be described using Markov models derived for each of the logic solver configurations. Using these models the performance parameters, PFDavg and MTTFS, for the configurations will be calculated. An important aspect why end-users / operating companies are more favorable of the General Purpose Hot-Standby PLC compared to a fully redundant Safety PLC is the perceived cost of ownership. However, especially when considering applications that need to achieve SIL2, extra validation steps need to be taken to ensure the suitability of the logic solver for that Safety Integrity Level. The Safety PLC manufacturer has performed these additional validation steps, whereas the General Purpose PLC manufacturer has not. This means that the extra validation steps need to be performed by the end-user / operating companies which will drastically influence the cost of ownership. The cost benefits of each of the logic solver configurations will also be discussed in this paper.
The presented self-tuning nonlinear controller ASPECT (Advanced control algorithms for programmable logic controllers) is intended for control of a practically important class of nonlinear processes that may be repres...
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In order to make electronic products such as Personal Digital Assistants (PDA) and cellular phones be small and thin, their components must be also small and thin. Since it is very difficult to inspect these small com...
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In order to make electronic products such as Personal Digital Assistants (PDA) and cellular phones be small and thin, their components must be also small and thin. Since it is very difficult to inspect these small components by human eyes, an automation system for inspecting them has been used. Compared with inspection systems for large or medium size components, those for small components need to be more precise. In particular, more precise timing for each action in the inspection system of small components is required. programmable logic controllers (PLC) have been used for generating precise timing signals. However, it is neither convenient nor economical to generate timing signals by PLC. In this paper, a low-cost programmable timing controller to generate precise signals in the inspection system of small components is proposed and it is applied to an inspection system of multilayer chip capacitors (MLCC). Since the proposed controller is organized to have internal registers, counters, and software routines for generating timing signals, users do not have to program the details about timing signals and need to only send some values about an inspection system through an RS232C port. By selecting theses values appropriate for a given inspection system, desired timing signals can be generated.
Within the electricity and telecommunication businesses of Eskom, research examined the latest developments associated with Power Line Communication (PLC) technology. PLC is the first technology that couples electrici...
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Within the electricity and telecommunication businesses of Eskom, research examined the latest developments associated with Power Line Communication (PLC) technology. PLC is the first technology that couples electricity with communication services. Communication services relating to access and connectivity are provided concurrently with services for electricity. The PLC Proof of Concept delivered to the end-users their regular energy demands together with the provisioning of communication services on an existing electrical grid. Business value was attained from the research investigations of the PLC technology. Eskom, is today in a better position to understand how integrated services produce cost reductions through the convergence of customer electricity demand together with communication services on one network. Eskom can proclaim that the research undertaken has delivered a proof of concept that now opens a variety of commercial opportunities for electricity and communication services. This paper describes the research approach that led to the proof of concept in the form of a trial site. References to the findings, experiences and testing are explained in the paper. Further investigations are recommended, so that PLC as an access technology can become part of the Next Generation Network (NGN). Eskom can greatly benefit not only in terms of incremental revenue generation, but also from future partnership developments.
According to some key technical problems of hardware and software design of PLC, we developed a new type of PLC. This type of PLC is in low cost and with a good performance. At the same time, we developed an Integrate...
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ISBN:
(纸本)0780378652
According to some key technical problems of hardware and software design of PLC, we developed a new type of PLC. This type of PLC is in low cost and with a good performance. At the same time, we developed an Integrated Development Environment (IDE) for the PLC. We used C8051F, which comes from Cygnal Company when we designed our PLC. C8051F is a high-speed 8051-compatible micro-controller. And it is integrated with enough interfaces. This character of C8051F simplified the hardware structure of PLC. And, our IDE is based on the PLC Programming Language Standard IEC6113-3, supporting multi-language and graphic drive.
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