Microcontroller

>> Senin, 10 November 2008

Microcontroller


The integrated circuit from an Intel 8742, an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.
A microcontroller (also MCU or µC) is a functional computer system-on-a-chip. It contains a processor core, memory, and programmable input/output peripherals.
Microcontrollers include an integrated CPU, memory (a small amount of RAM, program memory, or both) and peripherals capable of input and output.[1]
It emphasizes high integration, in contrast to a microprocessor which only contains a CPU (the kind used in a PC). In addition to the usual arithmetic and logic elements of a general purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data storage, read-only memory for program storage, Flash memory for permanent data storage, peripherals, and input/output interfaces. At clock speeds of as little as 32KHz, microcontrollers often operate at very low speed compared to microprocessors, but this is adequate for typical applications. They consume relatively little power (milliwatts or even microwatts), and will generally have the ability to retain functionality while waiting for an event such as a button press or interrupt. Power consumption while sleeping (CPU clock and peripherals disabled) may be just nanowatts, making them ideal for low power and long lasting battery applications.
Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, remote controls, office machines, appliances, power tools, and toys. By reducing the size, cost, and power consumption compared to a design using a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to electronically control many more processes.

1 Embedded design
1.1 Interrupts
1.2 Programs
1.3 Other microcontroller features
2 Higher integration
3 Volumes
4 Programming environments
5 Types of microcontrollers
6 Interrupt latency
7 History
8 See also
9 Notes
10 External links

Embedded design
The majority of computer systems in use today are embedded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems. These are called embedded systems. While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system, and low software complexity. Typical input and output devices include switches, relays, solenoids, LEDs, small or custom LCD displays, radio frequency devices, and sensors for data such as temperature, humidity, light level etc. Embedded systems usually have no keyboard, screen, disks, printers, or other recognizable I/O devices of a personal computer, and may lack human interaction devices of any kind.

Interrupts
It is mandatory that microcontrollers provide real time response to events in the embedded system they are controlling. When certain events occur, an interrupt system can signal the processor to suspend processing the current instruction sequence and to begin an interrupt service routine (ISR). The ISR will perform any processing required based on the source of the interrupt before returning to the original instruction sequence. Possible interrupt sources are device dependent, and often include events such as an internal timer overflow, completing an analog to digital conversion, a logic level change on an input such as from a button being pressed, and data received on a communication link. Where power consumption is important as in battery operated devices, interrupts may also wake a microcontroller from a low power sleep state where the processor is halted until required to do something by a peripheral event.

Programs
Microcontroller programs must fit in the available on-chip program memory, since it would be costly to provide a system with external, expandable, memory. Compilers and assembly language are used to turn high-level language programs into a compact machine code for storage in the microcontroller's memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory, or program memory may be field-alterable flash or erasable read-only memory.

Other microcontroller features
Since embedded processors are usually used to control devices, they sometimes need to accept input from the device they are controlling. This is the purpose of the analog to digital converter. Since processors are built to interpret and process digital data, i.e. 1s and 0s, they won't be able to do anything with the analog signals that may be being sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form that the processor can recognize. There is also a digital to analog converter that allows the processor to send data to the device it is controlling.
In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the Programmable Interval Timer, or PIT for short. A PIT just counts down from some value to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the heater on, etc.
Time Processing Unit or TPU for short. Is essentially just another timer, but more sophisticated. In addition to counting down, the TPU can detect input events, generate output events, and other useful operations.
Dedicated Pulse Width Modulation (PWM) block makes it possible for the CPU to control power converters, resistive loads, motors etc.. without using lot's of CPU resources in tight timer loops.
Universal Asynchronous Receiver/Transmitter (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU.
For those wanting ethernet one can use an external chip like Crystal Semiconductor CS8900A, Realtek RTL8019, or Microchip ENC 28J60 (buggy). All of them allows easy interfacing with low pin count.

Higher integration
In contrast to general-purpose CPUs, microcontrollers may not implement an external address or data bus as they integrate RAM and non-volatile memory on the same chip as the CPU. Using fewer pins, the chip can be placed in a much smaller, cheaper package.
Integrating the memory and other peripherals on a single chip and testing them as a unit increases the cost of that chip, but often results in decreased net cost of the embedded system as a whole. Even if the cost of a CPU that has integrated peripherals is slightly more than the cost of a CPU + external peripherals, having fewer chips typically allows a smaller and cheaper circuit board, and reduces the labor required to assemble and test the circuit board.
A microcontroller is a single integrated circuit, commonly with the following features:
central processing unit - ranging from small and simple 4-bit processors to complex 32- or 64-bit processors
discrete input and output bits, allowing control or detection of the logic state of an individual package pin
serial input/output such as serial ports (UARTs)
other serial communications interfaces like I²C, Serial Peripheral Interface and Controller Area Network for system interconnect
peripherals such as timers, event counters, PWM generators, and watchdog
volatile memory (RAM) for data storage
ROM, EPROM, EEPROM or Flash memory for program and operating parameter storage
clock generator - often an oscillator for a quartz timing crystal, resonator or RC circuit
many include analog-to-digital converters
in-circuit programming and debugging support
This integration drastically reduces the number of chips and the amount of wiring and circuit board space that would be needed to produce equivalent systems using separate chips. Furthermore, and on low pin count devices in particular, each pin may interface to several internal peripherals, with the pin function selected by software. This allows a part to be used in a wider variety of applications than if pins had dedicated functions. Microcontrollers have proved to be highly popular in embedded systems since their introduction in the 1970s.
Some microcontrollers use a Harvard architecture: separate memory buses for instructions and data, allowing accesses to take place concurrently. Where a Harvard architecture is used, instruction words for the processor may be a different bit size than the length of internal memory and registers; for example: 12-bit instructions used with 8-bit data registers.
The decision of which peripheral to integrate is often difficult. The microcontroller vendors often trade operating frequencies and system design flexibility against time-to-market requirements from their customers and overall lower system cost. Manufacturers have to balance the need to minimize the chip size against additional functionality.
Microcontroller architectures vary widely. Some designs include general-purpose microprocessor cores, with one or more ROM, RAM, or I/O functions integrated onto the package. Other designs are purpose built for control applications. A microcontroller instruction set usually has many instructions intended for bit-wise operations to make control programs more compact. For example, a general purpose processor might require several instructions to test a bit in a register and branch if the bit is set, where a microcontroller could have a single instruction that would provide that commonly-required function.
Microcontrollers typically do not have a math coprocessor, so floating point multiplication and division are carried out using a standard library, or the faster and more compact Horner method.

Volumes
About 55% of all CPUs sold in the world are 8-bit microcontrollers. According to Semico, Over 4 billion 8-bit microcontrollers were sold in 2006.[2]
A typical home in a developed country is likely to have only four general-purpose microprocessors but around three dozen microcontrollers. A typical mid range automobile has as many as 30 or more microcontrollers. They can also be found in any electrical device: washing machines, microwave ovens, telephones etc.

A PIC 18F8720 microcontroller in an 80-pin TQFP package.
Manufacturers have often produced special versions of their microcontrollers in order to help the hardware and software development of the target system. Originally these included EPROM versions that have a "window" on the top of the device through which program memory can be erased by ultra violet light, ready for reprogramming after a programming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been replaced by EEPROM and flash, which are easier to use (can be erased electronically) and cheaper to manufacture.
Other versions may be available where the ROM is accessed as an external device rather than as internal memory, however these are becoming increasingly rare due to the widespread availability of cheap microcontroller programmers.
The use of field-programmable devices on a microcontroller may allow field update of the firmware or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product.
Where hundreds of thousands of identical devices are required, using parts programmed at the time of manufacture can be an economical option. These 'Mask Programmed' parts have the program laid down in the same way as the logic of the chip, at the same time.

Programming environments
Microcontrollers were originally programmed only in assembly language, but various high-level programming languages are now also in common use to target microcontrollers. These languages are either designed specially for the purpose, or versions of general purpose languages such as the C programming language. Compilers for general purpose languages will typically have some restrictions as well as enhancements to better support the unique characteristics of microcontrollers. Some microcontrollers have environments to aid developing certain types of applications. Microcontroller vendors often make tools freely available to make it easier to adopt their hardware.
Many microcontrollers are so quirky that they effectively require their own non-standard dialects of C, such as SDCC for the 8051, which prevent using standard tools (such as code libraries or static analysis tools) even for code unrelated to hardware features. Interpreters are often used to hide such low level quirks.
Interpreter firmware is also available for some microcontrollers. For example, BASIC on the early microcontrollers Intel 8052[3]; BASIC and FORTH on the Zilog Z8[4] as well as some modern devices. Typically these interpreters support interactive programming.
Simulators are available for some microcontrollers, such as in Microchip's MPLAB environment. These allow a developer to analyse what the behaviour of the microcontroller and their program should be if they were using the actual part. A simulator will show the internal processor state and also that of the outputs, as well as allowing input signals to be generated. While on the one hand most simulators will be limited from being unable to simulate much other hardware in a system, they can exercise conditions that may otherwise be hard to reproduce at will in the physical implementation, and can be the quickest way to debug and analyse problems.
Recent microcontrollers are often integrated with on-chip debug circuitry that when accessed by an In-circuit emulator via JTAG, allow debugging of the firmware with a debugger

Programming
PLC programs are typically written in a special application on a personal computer, then downloaded by a direct-connection cable or over a network to the PLC. The program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory. Often, a single PLC can be programmed to replace thousands of relays.
Under the IEC 61131-3 standard, PLCs can be programmed using standards-based programming languages. A graphical programming notation called Sequential Function Charts is available on certain programmable controllers.
Recently, the International standard IEC 61131-3 has become popular. IEC 61131-3 currently defines five programming languages for programmable control systems: FBD (Function block diagram), LD (Ladder diagram), ST (Structured text, similar to the Pascal programming language), IL (Instruction list, similar to assembly language) and SFC (Sequential function chart). These techniques emphasize logical organization of operations.
While the fundamental concepts of PLC programming are common to all manufacturers, differences in I/O addressing, memory organization and instruction sets mean that PLC programs are never perfectly interchangeable between different makers. Even within the same product line of a single manufacturer, different models may not be directly compatible.

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Assembly line

Assembly line


This article needs additional citations for verification.Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2008)

Modern car assembly line.
An assembly line is a manufacturing process in which parts (usually interchangeable parts) are added to a product in a sequential manner using optimally planned logistics to create a finished product much faster than with handcrafting-type methods. The best known form of the assembly line, the moving assembly line, was realized into practice by Ford Motor Company between 1908 and 1915, and made famous in the following decade by the social ramifications of mass production, such as the affordability of the Ford Model T and the introduction of high wages for Ford workers. However, the various preconditions for the development at Ford stretched far back into the 19th century. Ford was the first company to build large factories around the concept. Mass production via assembly lines is widely considered to be the catalyst which initiated the modern consumer culture by making possible low unit costs for manufactured goods.
1 Concept
2 History
2.1 Overview: a culmination of many efforts
2.2 The Terracotta Army (circa 215 BC)
2.3 Venetian Arsenal (1500s)
2.4 Block production at Portsmouth: Brunel, Maudslay, et al (1800-1820s)
2.5 Eli Whitney (1780s-1820s)
2.6 Firearms, clocks, et al (1860s-1890s)
2.7 Ransom E. Olds (1890s-1900s)
2.8 Ford Motor Company (1908-1915)
3 Sociological problems
4 See also
5 References
6 Bibliography
7 External links


Concept
Consider the assembly of a car: assume that certain steps in the assembly line are to install the engine, install the hood, and install the wheels (in that order, with arbitrary interstitial steps). A car on the assembly line can have only one of the three steps done at once. After the car has its engine installed, it moves on to having its hood installed, leaving the engine installation facilities available for the next car. The first car then moves on to wheel installation, the second car to hood installation, and a third car begins to have its engine installed. If engine installation takes 20 minutes, hood installation takes 5 minutes, and wheel installation takes 10 minutes, then finishing all three cars when only one car can be operated at once would take 105 minutes.
On the other hand, using the assembly line, the total time to complete all three cars is 75 minutes. This is possible because there are 3 different installation stations, an engine station, a hood station and a wheels station. By having 3 stations, a total of 3 different cars can be operated at the same time, albeit all working on different steps. After finishing on the first car, the engine installation crew can move onto the second car. While the engine installation crew works on the second car, the first car can be moved to the hood station and then the wheels station to be fitted with the hood and the wheels respectively. After the engine has been installed on the second car, the second car moves to the hood and then the wheels assembly (5 minutes after the wheels assembly is done with the first car), at the same time the third car moves onto the engine assembly. When the third car’s engine has been mounted, it then can be moved to the hood and then wheels installation facilities, meanwhile subsequent cars (if any) can be move to the engine installation station. Because it takes 20 minutes to finish work on the engine while it takes only 15 minutes to complete the installation of both the hood and the wheels, the bottleneck is at the engine installation. Hence, additional cars will come off the assembly line at 20 minute increments.
Assembly lines don't increase the speed of producing a single unit, but only increases rate when there are a stream of units to be produced. In the example above, a car will still require 35 minutes to be made, however when there is a stream of cars it will only take 20 minutes to have a new car coming off the assembly line.

History

1913 Ford Model T assembly line.

[edit] Overview: a culmination of many efforts
The assembly line concept was not "invented" at one time by one person, and no one person is the "father" of it. It has been independently redeveloped throughout history based on logic. Its exponentially larger development at the end of the 19th century and beginning of the 20th occurred among various people over decades, as other aspects of technology allowed. The development of toolpath control via jigs, fixtures, and machine tools (such as the screw-cutting lathe and milling machine) during the 19th century provided the prerequisites by making interchangeable parts a practical reality. Before the 20th century, the way that most manufactured products were made was that a single craftsman or team of craftsmen would create each part of a product individually by hand, using their skills and such tools as files and knives, and assemble them together into an assembly, making cut-and-try changes in the parts so that they would fit and work together (the so-called English System). The transition to other methods began as creativity and logic took advantage of the opportunities that the aforementioned machining developments presented. Thus, before the modern assembly line took shape, there were prototypical forms in various industries, as outlined below.

The Terracotta Army (circa 215 BC)
The Terracotta Army commissioned by the first Chinese Emperor Qin Shi Huangdi is a collection of about 8000 life-sized clay soldiers and horses buried with the emperor. The figures had their separate body parts manufactured by different workshops that were later assembled to completion. Notably, each workshop inscribed its name on the part they manufactured to add traceability for quality control.

Venetian Arsenal (1500s)
At the peak of its efficiency in the early 16th century, the Venetian Arsenal employed some 16,000 people who apparently were able to produce nearly one ship each day, and could fit out, arm, and provision a newly-built galley with standardized parts on an assembly-line basis not seen again until the Industrial Revolution.

Block production at Portsmouth: Brunel, Maudslay, et al (1800-1820s)
Probably the first linear and continuous assembly line of post-Renaissance times was created in 1801 by Marc Isambard Brunel (father of Isambard Kingdom Brunel), with the help of Henry Maudslay and others, for the production of blocks for the Royal Navy. This assembly line was so successful it remained in use until the 1960s, with the workshop still visible at HM Dockyard in Portsmouth, and still containing some of the original machinery.

Eli Whitney (1780s-1820s)
Eli Whitney is sometimes credited with developing the armory system of manufacturing in 1801, using the ideas of division of labor, engineering tolerance, and interchangeable parts to create assemblies from parts in a repeatable manner. But Whitney's contribution was mostly as a popularizer rather than "the inventor" of repeatability. He was probably inspired by several others (including Honoré Blanc), or at least by the contemporary zeitgeist that was building around such ideas. Thomas Jefferson had tried to bring a French mechanic (who was almost certainly Blanc) and his methods to America in 1785, but the project never went anywhere.[1] A few years later, Whitney and his American contemporaries succeeded in introducing the relevant concepts (interchangeable parts, toolpath control via machine tools and jigs, transfer of skill to the equipment allowing use of semi-skilled or unskilled machine operators) to American firearm manufacture.

Firearms, clocks, et al (1860s-1890s)
The Industrial Revolution in Western Europe and North America, but perhaps most especially in Great Britain and New England, led to a proliferation of manufacturing and invention. Many industries, notably textiles, firearms, clocks and watches,[2] buttons, railroad cars and locomotives, sewing machines, and bicycles, saw expeditious improvement in materials handling, machining, and assembly during the 19th century, although modern concepts such as industrial engineering and logistics had not yet been named.

Ransom E. Olds (1890s-1900s)
Ransom Olds patented the assembly line concept,[citation needed] which he put to work in his Olds Motor Vehicle Company factory in 1901, becoming the first company in America to mass-produce automobiles. This development is often overshadowed by the independent redevelopment of assembly-line work at Ford Motor Company a few years later (see below), which introduced the ramifications of the method to a wider audience. The work of Olds shows clearly the flaws in the oversimplistic storyline of Ford's having "invented" the assembly line.

Ford Motor Company (1908-1915)
The assembly line developed for the Ford Model T had immense influence on the world. Despite oversimplistic attempts to attribute it to one man or another, it was in fact a composite development based on logic that took 7 years and plenty of intelligent men. The principal leaders are discussed below.
The basic kernel of an assembly line concept was introduced to Ford Motor Company by William "Pa" Klann upon his return from visiting a Chicago slaughterhouse and viewing what was referred to the "disassembly line", where animals were butchered as they moved along a conveyor. The efficiency of one person removing the same piece over and over caught his attention. He reported the idea to Peter E. Martin, soon to be head of Ford production, who was doubtful at the time but encouraged him to proceed. Others at Ford have claimed to have put the idea forth to Henry Ford, but Pa Klann's slaughterhouse revelation is well documented in the archives at the Henry Ford Museum[citation needed] and elsewhere, making him an important contributor to the modern automated assembly line concept. The process was an evolution by trial and error of a team consisting primarily of Peter E. Martin, the factory superintendent; Charles E. Sorensen, Martin's assistant; C. Harold Wills, draftsman and toolmaker; Clarence W. Avery; and Charles Ebender. Some of the groundwork for such development had recently been laid by the intelligent layout of machine tool placement that Walter Flanders had been doing at Ford up to 1908.
In 1922 Ford (via his ghostwriter Crowther) said of his 1913 assembly line, "I believe that this was the first moving line ever installed. The idea came in a general way from the overhead trolley that the Chicago packers use in dressing beef."[3]
Charles E. Sorensen, in his 1956 memoir My Forty Years with Ford, presented a different version of development that was not so much about individual “inventors” as a gradual, logical development of industrial engineering:
“Years later in My Life and Work, a book which was written for him, Mr. Ford said that the conveyor-assembly idea occurred to him after watching the reverse process in packing houses where hogs and steers were triced up by hind legs on an overhead conveyor and disassembled. This is a rationalization long after the event. Mr. Ford had nothing to do with originating, planning, and carrying out the assembly line. He encouraged the work, his vision to try unorthodox methods was an example to us; and in that there is glory enough for all.”[4]
“Henry Ford had no ideas on mass production. He wanted to build a lot of autos. He was determined but, like everyone else at that time, he didn’t know how. In later years he was glorified as the originator of the mass production idea. Far from it; he just grew into it, like the rest of us. The essential tools and the final assembly line with its many integrated feeders resulted from an organization which was continually experimenting and improvising to get better production.”“What was worked out at Ford was the practice of moving the work from one worker to another until it became a complete unit, then arranging the flow of these units at the right time and the right place to a moving final assembly line from which came a finished product. Regardless of earlier uses of some of these principles, the direct line of succession of mass production and its intensification into automation stems directly from what we worked out at Ford Motor Company between 1908 and 1913. [¶] Henry Ford is generally regarded as the father of mass production. He was not. He was the sponsor of it.”[6] [Sorensen explains that Henry Ford did not invent all the aspects of mass production, but he knew that production efficiency meant low unit price, and so he encouraged his engineers to develop the methods.]
“Today historians describe the part the Ford car played in the development of that era and in transforming American life. We see that now. But we didn’t see it then; we weren’t as smart as we have been credited with being. All that we were trying to do was to develop the Ford car. [¶] The achievement came first. Then came logical expression of its principles and philosophy.”
Much has been written about the original layout of the assembly line at Ford. In an article published by Fortune Magazine in June 1944, Henry Ford said that he and Peter E. Martin did it.
As a result of these developments in method, Ford's cars came off the line in three minute intervals. This was much faster than previous methods, increasing production by eight to one (requiring 12.5 man-hours before, 1 hour 33 minutes after), while using less manpower.It was so successful, paint became a bottleneck. Only Japan black would dry fast enough, forcing the company to drop the variety of colors available before 1914, until fast-drying Durco lacquer was developed in.In 1914, an assembly line worker could buy a Model T with four months' pay
Ford's complex safety procedures—especially assigning each worker to a specific location instead of allowing them to roam about—dramatically reduced the rate of injury. The combination of high wages and high efficiency is called "Fordism," and was copied by most major industries. The efficiency gains from the assembly line also coincided with the take off of the United States. The assembly line forced workers to work at a certain pace with very repetitive motions which led to more output per worker while other countries were using less productive methods.
Ford at one point considered suing other car companies because they used the assembly line in their production, but decided against, realizing it was essential to creation and expansion of the industry as a whole.
In the automotive industry, its success was dominating, and quickly spread worldwide. Ford France and Ford Britain in 1911, Ford Denmark 1923, Ford Germany 1925; in 1921, Citroen was the first native European manufacturer to adopt it. Soon, companies had to have assembly lines, or risk going broke by not being able to compete; by 1930, 250 companies which did not had disappeared.[2]

Sociological problems
Sociological work has explored the social alienation and boredom that some workers feel because of the repetition of doing the same specialized task all day long.[8] Because workers have to stand in the same place for hours and repeat the same motion hundreds of times per day, repetitive stress injuries are a possible pathology of occupational safety. Industrial noise also proved dangerous. When it was not too high, workers were often prohibited from talking. Charles Piaget, a skilled worker at the LIP factory, recalled that beside being prohibited from speaking, the semi-skilled workers had only 25 centimeters in which to move.[9] Industrial ergonomics later tried to minimize physical trauma.

References
^ Roe 1916, p. 129-130.
^ a b c d e Georgano 1985.
^ Ford 1922, p. 81.
^ Sorensen 1956, p. 129.
^ Sorensen 1956, p. 128.
^ Sorensen 1956, p. 116.
^ Sorensen 1956, p. 131.
^ Alienation and Freedom: The Factory Worker and His Industry, Robert Blauner, in Technology and Culture, Vol. 6, No. 3 (Summer, 1965), pp. 518-519 (English)
^ Leçons d'autogestion (Autogestion Lessons), interview with Charles Piaget (French)

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LEARNINGPLC

>> Minggu, 09 November 2008

24-Jul-2001 » Training Press Releases » Acquisition significantly increases GTSLearning's market penetration and breadth of portfolio
LONDON, ENGLAND - July 24, 2001 - GTSLearning plc, a leading international provider of education products and services for the IT sector, today announced the acquisition of UK-based CourseWare Company Limited. This acquisition significantly broadens GTSLearning's portfolio of courseware and consolidates its market position. The CourseWare Company was established in 1994 to market quality-driven instructor-led course materials to training providers and is currently selling over 500 different courses in 30 countries. The business and all personnel will be integrated into GTSLearning plc and the "CourseWare Company" brand will be retained. "Over the past twelve months, GTSLearning plc has embarked on an aggressive expansion plan to add new product ranges to our portfolio. We took the decision to enter the Internet learning space through a strategic agreement with iGeneration, we contracted with the Help Desk Institute to provide certification training for Help Desk Professionals, and now,with the CourseWare Company, we have significantly grown our portfolio of desktop and support courses" said Robin Adda, Managing Director of GTSLearning plc. James Minter, Managing Director of the CourseWare Company will assume responsibility of Courseware Director for GTSLearning plc. Minter added: "We are very excited about joining forces with a world class education provider such as GTSLearning. For some time now, we have recognised the strengths of GTSLearning's international operations. We are confident that our combined business offering represents a very strong content opportunity for learning providers across the globe ". With immediate effect, GTSLearning will begin marketing the CourseWare Company products (including the LearnIT self-study series for ECDL/ICDL and Microsoft Office XP courseware) to its network of GTSpartners. Existing customers of the CourseWare Company will also have immediate access to GTSLearning's broad range of products. - ENDS -
About gtslearning gtslearning is a global supplier of learning content for business skills and IT training. gtslearning products include printed courseware and licenses, CD-based interactive CBT (computer-based training) and a full portfolio of online and blended learning solutions. Represented through nine international sales offices, gtslearning supplies commercial and academic education providers, corporates and individual learners in more than 50 countries worldwide. gtslearning is a winner of several key industry awards, notably CompTIA's Gold Award of Excellence, Technology Award, Gold Training Materials Provider Award and A+ Committee Member Award 2006. gtslearning was also awarded Element K's 2005 Circle of Excellence award for online learning solutions gtslearning's Managing Director, Robin Adda, is the sole International Representative Board Member of CompTIA's Board of Directors.

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learningPLC

>> Jumat, 07 November 2008

Automation






automation (ancient Greek: = self dictated), roboticization or industrial automation or numerical control is the use of control systems such as computers to control industrial machinery and processes, reducing the need for human intervention.[1] In the scope of industrialization, automation is a step beyond mechanization. Whereas mechanization provided human operators with machinery to assist them with the physical requirements of work, automation greatly reduces the need for human sensory and mental requirements as well. Processes and systems can also be automated.
Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities.
Many roles for humans in industrial processes presently lie beyond the scope of automation. Human-level pattern recognition, language recognition, and language production ability are well beyond the capabilities of modern mechanical and computer systems. Tasks requiring subjective assessment or synthesis of complex sensory data, such as scents and sounds, as well as high-level tasks such as strategic planning, currently require human expertise. In many cases, the use of humans is more cost-effective than mechanical approaches even where automation of industrial tasks is possible.
Specialised hardened computers, referred to as programmable logic controllers (PLCs), are frequently used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events. This leads to precisely controlled actions that permit a tight control of almost any industrial process.
Human-machine interfaces (HMI) or computer human interfaces (CHI), formerly known as man-machine interfaces, are usually employed to communicate with PLCs and other computers, such as entering and monitoring temperatures or pressures for further automated control or emergency response. Service personnel who monitor and control these interfaces are often referred to as stationary engineers.[2]
Social impact
Automation has had a notable impact in a wide range of highly visible industries beyond manufacturing. Once-ubiquitous telephone operators have been replaced largely by automated telephone switchboards and answering machines. Medical processes such as primary screening in electrocardiography or radiography and laboratory analysis of human genes, sera, cells, and tissues are carried out at much greater speed and accuracy by automated systems. Automated teller machines have reduced the need for bank visits to obtain cash and carry out transactions. In general, automation has been responsible for the shift in the world economy from agrarian to industrial in the 19th century and from industrial to services in the 20th century
The widespread impact of industrial automation raises social issues, among them its impact on employment. Historical concerns about the effects of automation date back to the beginning of the industrial revolution, when a social movement of English textile machine operators in the early 1800s known as the Luddites protested against Jacquard's automated weaving looms[4] — often by destroying such textile machines— that they felt threatened their jobs. One author made the following case. When automation was first introduced, it caused widespread fear. It was thought that the displacement of human operators by computerized systems would lead to severe unemployment.
Critics of automation contend that increased industrial automation causes increased unemployment; this was a pressing concern during the 1980s. One argument claims that this has happened invisibly in recent years, as the fact that many manufacturing jobs left the United States during the early 1990s was offset by a one-time massive increase in IT jobs at the same time. Some authors argue that the opposite has often been true, and that automation has led to higher employment. Under this point of view, the freeing up of the labour force has allowed more people to enter higher skilled managerial as well as specialised consultant/contractor jobs (like cryptographers), which are typically higher paying. One odd side effect of this shift is that "unskilled labour" is in higher demand in many first-world nations, because fewer people are available to fill such jobs.
At first glance, automation might appear to devalue labor through its replacement with less-expensive machines; however, the overall effect of this on the workforce as a whole remains unclear. Today automation of the workforce is quite advanced, and continues to advance increasingly more rapidly throughout the world and is encroaching on ever more skilled jobs, yet during the same period the general well-being and quality of life of most people in the world (where political factors have not muddied the picture) have improved dramatically. What role automation has played in these changes has not been well studied.
Current emphasis
Currently, for manufacturing companies, the purpose of automation has shifted from increasing productivity and reducing costs, to broader issues, such as increasing quality and flexibility in the manufacturing process.
The old focus on using automation simply to increase productivity and reduce costs was seen to be short-sighted, because it is also necessary to provide a skilled workforce who can make repairs and manage the machinery. Moreover, the initial costs of automation were high and often could not be recovered by the time entirely new manufacturing processes replaced the old. (Japan's "robot junkyards" were once world famous in the manufacturing industry.)
Automation is now often applied primarily to increase quality in the manufacturing process, where automation can increase quality substantially. For example, automobile and truck pistons used to be installed into engines manually. This is rapidly being transitioned to automated machine installation, because the error rate for manual installment was around 1-1.5%, but has been reduced to 0.00001% with automation. Hazardous operations, such as oil refining, the manufacturing of industrial chemicals, and all forms of metal working, were always early contenders for automation.
Another major shift in automation is the increased emphasis on flexibility and convertibility in the manufacturing process. Manufacturers are increasingly demanding the ability to easily switch from manufacturing Product A to manufacturing Product B without having to completely rebuild the production lines. Flexibility and distributed processes have led to the introduction of Automated Guided Vehicles with Natural Features Navigation.

Automation tools
Different types of automation tools exist:
ANN - Artificial neural network
DCS - Distributed Control System
HMI - Human Machine Interface
SCADA - Supervisory Control and Data Acquisition
PLC - Programmable Logic Controller
























































































































































































































































































































































































































































































































































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