The most popular programmable automation controlle

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The rise of programmable automation controller

pac is an embedded controller specially designed for industrial automation applications, which can carry out logic, action, process control and video work. But 30 years ago, this technology was owned by a small number of countries and enterprises. How did it change from an expensive PLC to a technology benefiting the public

30 years ago, most industrial manufacturing processes were either controlled by hardwired relay logic or by analog cycle controllers; At that time, the memory of the three computer systems in the space shuttle was less than 100 kb, but a whole set of complex programs had to be executed in such memory space; Similarly, 30 years ago, there was no personal computer (PC)

in the past 30 years, we have cut through difficulties all the way from hardwired relays to analog controllers, and the evolution and change of computers have gone beyond the realm imaginable in the 1970s

initial stage: programmable logic controller plc

in the 1970s, microprocessors were slow, expensive and prone to failure, and memory was even more expensive. The challenge faced by Richard Morley of Bedford associates (who later introduced "modular digital controller", Modicon) and Otto struger of Allen Bradley is how to introduce a device called "programmable logic controller (PLC) in the automotive industry to try to eliminate the costs associated with redesigning and reconnecting hardwired relay logic. As the automobile industry saves a staggering cost when importing PLC, this device has become very popular

medium term: personal computer pc

30 years ago, office computing was all completed by microcomputer and mainframe computer system. Most computers are independent, but some people began to experiment with building several computers into a network to perform simple word processing or spreadsheets. The licensing cost of each set of software developed exceeded 10000 dollars. Memory and storage devices are extremely expensive, and the quantity is very scarce. After that, apple, IBM, and many other manufacturers developed simple and cheap personal computers. By the end of the 1990s, PC had become the standard equipment for business and manufacturing computing all over the world

later stage: programmable automatic control 2 is to promote the progress and development of plastic blending technology, new products of plastic additives and utilization technology. Pac

as the price of personal computers becomes cheaper and cheaper, the memory and processor capabilities become stronger and stronger, and the reliability becomes more and more important. By the beginning of 2000, these researches had developed into a programmable automation controller called PAC (Programmable Automation Co), which Chinese plastic machinery enterprises have increased the development of new markets for extruders in recent years. Craig Resnick of ARC Advisory Group is the creator of this term, that is, to replace the ladder logic programmable PLC with a personal computer architecture. In 2002, he wrote that PAC includes: logic, motion and process control functions can be executed on a single platform, and different application requirements can be met by a single development tool, a single database and the same tag. It can also provide cross machine or cross process unit software tools. With an open and modular architecture, it adopts standard network interfaces and programming languages. Systems of different manufacturers can also exchange data with each other

where does the programmable automation controller PAC apply

compared with the traditional PLC design, the advantages of PAC include: it can connect the general network and provide connectivity with wireless network and fieldbus; Support multiple communication protocols; CPU with high computing efficiency; Commercial operating systems can be used, such as DOS, Linux, Windows CE, etc; Provide large memory and data storage space; SCADA/HMI can be controlled simultaneously by a single platform; Provide higher performance control algorithm; Large amount of data processing; Develop customized control function library; Complex process control simulation can be carried out. In fact, PAC can be used in all kinds of applications that used hard wired relays, analog controllers, or PLC before or now. Of course, there are a few exceptions, such as controls that require very fast movement, or safety device systems (SIS)

great changes in embedded computing

pac was born as a result of the popularization of "embedded computing", which means that almost every device has a built-in processor. In fact, PAC is an embedded controller specially designed for industrial automation applications

therefore, with the continuous growth of the embedded computing market, it not only drives the vigorous development of the PAC market, but also the latest technology of embedded computing can be applied to the PAC embedded controller. The PAC is very similar to the PC with PLC or desktop computer. First, you must select the hardware and operating system, and then select the matching peripheral devices; Finally, select the application to be executed by PAC. The biggest advantage of PAC over PLC is that most programmers are proficient in using these high-level languages to write programs, and relatively few know how to use ladder diagrams. Therefore, PAC using Windows operating system allows users and machinery manufacturers to take se2020 fiberglass yarn from 3B group to benefit from a huge program code database in terms of reinforcing materials for the blade

with PAC, you can select operating system (OS)

pac has built-in DOS or windows operating system, or provides Linux OS. Although DOS is no longer popular, it still has some advantages that other operating systems do not have. First of all, DOS does not need to be updated frequently when using high voltage and Linux in Windows experiments, so the program code written in DOS PAC will not be outdated or potentially damaged due to updates and patches. Of course, DOS is also more cost-effective, allowing end users or machinery manufacturers to operate with lower power requirements and lower heat dissipation requirements. It is easier to achieve fanless PAC operation with DOS PAC

on the other hand, the PAC of Windows CE can give full play to most windows functions in applications, peripheral devices and network communication. The windows operating system allows users to connect the touch panel or flat panel monitor to the VGA interface of the controller. In fact, PAC is usually built into a composite unit to integrate the display and controller in the same box

the user can install the panel software into the controller, and can use a relatively low-cost flat panel to replace the touch panel. Windows CE as the PAC operating system can also use some special modules that dos cannot do, such as connecting through Ethernet and USB

with hardware, the next step is software. The PAC system has three types of software. The first is the operating system, as mentioned above; Next is programming software; Finally, the application software program that can be executed on PAC

most people familiar with PLC are used to ladder diagram or one of IEC program languages. Most people who are familiar with personal computers are used to programming in higher-level programming languages, such as visual basic, c++, Visual C, etc. PAC can be compatible with ladder diagram, structure text, or PLC central program language of FBD, and can be immediately used as remote terminal unit (RTU) in SCADA system. It can even execute man-machine interface (HMI) system, and can be used as a point-to-point node in distributed network control system

the PAC design with embedded Windows CE system can be easily integrated into the standard Ethernet network with industrial Ethernet switch

other advantages of using Windows PAC include the ability to execute existing programs and applications on the same machine responsible for operating the manufacturing process controller. It is quite easy to integrate control data history and HMI with PAC, and it is difficult for traditional PLC design to achieve this. In the past decade, PAC has proved with strength that it can achieve more durable, reliable, powerful and widely accepted by the market with the help of the existing software and hardware in the market

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