Development and application of programmable contro

Development and application of programmable controller in China

1 Introduction

programmable controller is a new generation of industrial control device based on microprocessor and integrating computer, communication, interconnection and automatic control technology. Programmable controller has been developed and applied in China for more than 30 years. Now it has been widely used in various industrial production fields of the national economy and has become an important equipment and powerful pillar to improve the level and technical ability of traditional industrial equipment. With the development of global integration economy, it should be the direction of the majority of technicians to strive to develop the large-scale application of programmable controller in China and form the programmable controller technology with independent intellectual property rights

2 development history of programmable controller

programmable controller came out in the 1960s. At that time, the functions of programmable controller were very simple, only logic, timing, counting and other functions; In terms of hardware, the integrated circuit for programmable controller has not been put into large-scale industrial production, and the CPU is composed of discrete components; The memory is magnetic core memory with limited storage capacity; Generally, there are only twenty or thirty user instructions, and there is no formed programming language; Single model, no series. A programmable controller can only replace the control system composed of 200 ~ 300 relays at most. In terms of volume, it can be said to be a behemoth compared with the current programmable controller

in the 1970s, with the industrial production of small and medium-sized integrated circuits, the technology of programmable controller has been greatly developed. In addition to logic operation, the programmable controller adds numerical operation, computer interface, analog control, etc; The software development has self diagnosis program, and the program storage starts to use EPROM; The reliability is further improved, a series is initially formed, the structure begins to distinguish between modular and integral, and the function of the whole machine transitions from special to general

in the late 1970s and early 1980s, microprocessor technology became more and more mature, single-chip microprocessor and semiconductor memory entered industrial production, and large-scale integrated circuits began to be widely used. The programmable controller began to develop to multiprocessor, which greatly enhanced the function and processing speed of the programmable controller, and had the ability of communication and remote I/O. a variety of special functions were added, such as floating-point operation, trigonometric function, look-up table, list, etc. the self diagnosis and fault-tolerant technology also developed rapidly

from the late 1980s to the mid-1990s, with the popularization and application of computer and network technology and the rapid development of VLSI, gate array and ASIC, the CPU of programmable controller has been developed into 16 bit or 32-bit microprocessor, and the processing speed has been greatly improved. The functions of high-speed counting, interrupt, PID and motion control have been introduced into programmable controller. The programmable controller has completely replaced the traditional logic control device, analog instrument control device and DDC (direct digital control) control device with minicomputer as the core. Due to the enhanced connection ability, it can be connected with the upper computer, flex I/O or remote I/O, so it is no longer difficult to form a distributed control system (DCS). Ladder diagram language and statement table language are fully mature and basically standardized. SFC (sequential function diagram) language is gradually popularized. The special programmer has been replaced by personal computer and corresponding programming software. The man-machine interface device is becoming more and more perfect. It has been able to monitor and manage the whole plant, and redundant technology has been developed to greatly strengthen the reliability

in the 21st century, programmable controller still maintains a vigorous development momentum and continues to expand its application fields, such as configuring flexible manufacturing system (FMS) and computer integrated manufacturing system (CIMS) for users. At present, the programmable controller mainly expands in two directions: first, the integrated control system, which has broken through the original concept of programmable controller, closely combines the factory production process control with the information management system, and even prepares the technical foundation for MES and ERP system. This development trend will provide a solid technical foundation for the difficult ERP system, which will bring a change in industrial control, Realize the real electronic information chemical plant; Second, the micro programmable controller has sprung up. Its volume is like the size of the palm of the hand. Its function can cover the control function of single equipment and the whole workshop, and has the connection function. This kind of micro programmable controller enables the control system to extend its tentacles to all corners of the factory. With the acceleration of the process of world economic integration, while developing technology, developed countries pay more attention to the protection of the intellectual property rights of programmable controllers. Large international programmable controller manufacturers have joined the international standardization organization of programmable controllers. They use many technical standards to establish technical protection barriers in line with their economic interests

3 development of programmable controller in China

the development of programmable controller in China is different from that in the world. The development of programmable controller in the world is from research, development, production to application, while China is from the introduction of complete sets of equipment, the introduction and application of programmable controller, digestion and transplantation, joint venture production to wide application. It can be roughly divided into the following three stages:

(1) the primary understanding stage of programmable controller (from the late 1970s to the early 1980s)

the development of programmable controller in the world first aroused great interest in the domestic engineering and technical circles. Therefore, China's understanding of programmable controller began with the introduction of complete sets of equipment from the late 1970s to the early 1980s, At that time, a number of projects in Shanghai Baosteel Phase I project introduced more than a dozen models and more than 200 programmable controllers. These programmable controllers are used in the whole steel smelting and processing production line from raw material wharf to blast furnace, steel rolling and steel pipe, replacing the traditional relay logic system, and partially replacing analog control and small DDC system. Following the first phase project of Baosteel, most of the equipment and production lines successively introduced by many domestic manufacturers are equipped with programmable controllers, which are used in power stations, petrochemical industry, automobile manufacturing, ports, wharfs and other fields. It is in the process of introducing complete sets of equipment that we have opened our eyes and understood the programmable controller, which also promotes the development of the programmable controller in our country

(2) the introduction, application, digestion and transplantation stage of programmable controller (from the early 1980s to the early 1990s)

since the early 1980s, with the deepening of China's reform and opening up, with the introduction of complete sets of equipment, foreign original programmable controllers began to flow into the domestic market. Many departments and units have successively introduced programmable controllers and designed their own control systems. Their application scope has also been expanded to industrial fields such as building materials, light industry, coal, water treatment, food, pharmacy, papermaking, rubber and fine chemical industry

with the improvement of application ability and the expansion of market demand, some departments and units, in line with the policy of combining technology and trade, digestion and transplantation, are carrying out secondary development and Application Research on the one hand, and are also introducing production lines of programmable controllers, establishing joint ventures for the production of programmable controllers, and actively developing their own products on the other hand

at the same time, China also began to develop programmable controller products. At that time, more than 20 scientific research institutions, colleges and universities and factories were developing and producing programmable controllers in Shanghai, Beijing, Xi'an, Guangzhou, Changchun and other places. However, due to the lack of funds, follow-up research capacity and relatively backward production technology, they could only stay in the laboratory stage and could not be put into practical application and form industrial production

(3) extensive development stage of programmable controller (from the early 1990s to the present)

in the 1990s, China's programmable controller entered an extensive development stage, which is mainly reflected in the following aspects:

a. the government attached great importance to the development of

programmable controller, which was highly valued by the government. Under the leadership of the Ministry of machinery and electronics industry at that time, the programmable controller industry association was established in 1991. The programmable controller industry association plays a bridge role between the government and enterprises, communicates the situation, and provides a basis for decision-making. At the same time, the standardization of PLC has also attracted the attention of relevant departments. The programmable controller Standardization Technical Committee was established in 1993, which laid a foundation for the further development of programmable controller in our country

B. more widely used

at this stage, the application of programmable controller has penetrated into all departments of national economy and all corners of industrial process, and has become an important symbol for enterprises to improve the level of equipment technology. In Baosteel's phase II and phase III project, more than 600 sets of programmable controllers of more than 30 models from many foreign manufacturers are used, and nearly 200 programmable controllers of Rockwell Automation Company are used in the diesel engine production line of Guangxi Yuchai Machinery Co., Ltd. It is common to use programmable controllers on a large scale. At this stage, China's engineering and technical personnel have fully demonstrated the ability of design and application, software production and complete equipment. Recently, in the 1 million ton potassium chloride project in Qinghai Salt Lake, a key project of China's western development, which is designed by the author, complete sets, software development, installation and commissioning, the programmable controller is used to form the automatic control system of the whole plant, and the programmable controller is designed in the MCC cabinet to realize the comprehensive automation system covering more than 600 MCC cabinets and various process flows of the whole plant. The application project has attracted the attention of major foreign companies. Rockwell Automation invited project designers to the headquarters of the United States company for introduction

C. achievements in research, development and production

with the deepening of China's reform and opening up, foreign manufacturers are optimistic about China's market, set up their offices in China, and even set up their Asia Pacific headquarters in China. Domestic enterprises have introduced foreign technology, which has promoted the establishment of a number of technology introduction enterprises and joint ventures, and driven the technological development of China's programmable controller industry. Fortunately, since the early 1990s, due to the deepening application of programmable controllers, there has been a climax of independent research and development of programmable controllers in China. Although most of them are small programmable controllers and the batch is not large, their function, quality and reliability have been significantly improved. According to my understanding, the speed of tensile testing machine has 10 ~ 500 mm/min meter products, such as jh200 of Nanjing Jiahua, with I/O of 12 to 120 points, High speed counter and analog quantity function; The I/O of d20p of Hangzhou Xinjian company is 12/8 points, and the I/O of D100 can be expanded from 40 points to 120 points; Rd100 and rd200 of Lanzhou Quanzhi, the former has 9/4 points of I/O and 2 points of analog input, and the latter has 20 ~ 40 points of I/O. the extended functions include encoding disk speed measurement, thermocouple temperature measurement and analog I/O, which can connect 32 rd200 and communicate with PC in real time. At the same time, medium and large-scale programmable controllers also began to appear in China. Sti2000 of Shanghai Ship Transportation Research Institute of the Ministry of communications has 256 I/O points and 4096 I/O points when multiple units are connected; Beijing Heli ShigongHLN-J 100/200/500/1000/2000NM Digital Display Material Torsion Testing Machine
Grinding and Polishing
200 ton compression testing machine
Torsion Torque Testing Specimen Machine Apparatus
Manual Torsion Spring Tester