Practical application and work experience of DCS system - Database & Sql Blog Articles

First, the determination of system function requirements

Before choosing dcs, we must first clearly define the application goals, put forward the requirements for DCS functions, and determine the scale of the system. Generally, instrument automation, the person in charge of the process and the person in charge of the computer, and the person in charge of the design institute are required to discuss and determine in order to meet the requirements of production and operation to the utmost extent.

1. Apply the target of DCS

(1) Improve the production and management level of the device

Improve production efficiency (improve efficiency), reduce production costs, save energy, reduce consumption, improve product quality, improve flexibility and adaptability of production changes, improve equipment management level, improve scientific analysis of fault analysis and standardization of production management. Conducive to labor competition and tapping production potential.

(2) Improve the control level of the device

Realize device stabilization control and operation optimization, realize advanced control, realize sequential logic control, realize equipment fault diagnosis and interlock protection, realize optimal control of local or full equipment, improve production and management level, improve control level, In order to achieve the important role of the equipment "safe, stable, long, full, excellent" production, it has significant economic and social benefits.

These goals can be considered in stages, applied and developed step by step, and the system will be gradually expanded to achieve the ultimate goal.

2, system function requirements

(1) Data acquisition and storage functions: scan time of analog input signal, scan time of digital signal, type of historical data storage (including adjustment trend, historical trend), number of points and period, input signal processing function.

(2) Control function: It has complete monitoring, adjustment and sequence control functions, equipment operation monitoring, interlock protection and other functions. The maximum ability of feedback control function (type and quantity of input and output, logic operation capability, sequence steps, execution cycle) ), process control language capabilities (such as ST, FORTRAN, BASIC, C or other control languages), advanced control software requirements.

(3) Display function: CRT size, color, screen refresh time, screen type and quantity. The display screen includes a general picture, a flow chart screen, a control group screen, an adjustment screen, a trend screen, a process alarm screen, a system alarm screen, a system status screen, an operation log screen, a history query screen, etc., and has a window (multiple, pull) Stretch, overlap) display function, Chinese character function and touch screen function.

(4) Alarm function: analog input/output signal alarm (absolute alarm, rate of change alarm), digital input/output signal alarm, instrument deactivation (check, stop scan) alarm, system component (card, network) fault alarm , adjacent alarm time resolution, alarm management functions (such as historical query filtering, alarm group setting, priority of alarm point group, alarm suppression function, etc.).

(5) Report and screen copy function: real-time report function, timed report function (including time report, class report, daily report, monthly report, annual report), alarm summary record, operation record report, operation or parameter modification print, printer screen copy function.

(6) Operation safety: operation authority password inquiry function, engineer, operator key key function, MAN/AUT/CAS switching without disturbance function, redundancy measures.

(7) System flexibility: system reliability index, redundancy and redundancy, convenient system expansion, compatibility between new and old products, practicality with communication interface and software of host computer, communication with other models (openness) .

The system function requirements are determined according to the system objectives and specific content, especially highlighting the characteristics of specific projects:

a. The speed of the fast scan and the execution cycle of the sequence control and interlock must be specified according to the process indicators. For example, when a user introduces DCS into a DCS, the contractor's need for sequential control of the patent vendor is unclear. When the configuration was designed, it was found that the speed and capacity of the DCS could not meet the requirements of the process, so I purchased it. A set of plc adds investment.

b. The goal is to develop advanced control software, and the emphasis should be placed on the control functions and software development tools.

Second, the selection of DCS

1. Model selection principle

The selection of DCS models is an important task. Due to the rapid progress of DCS technology, the period of centralized update and replacement is very short. In the past, the era of monopolization by several major foreign DCS manufacturers has passed, and the national brand DCS manufacturers have rapidly developed and matured. It has occupied half of China's DCS market, and its performance, reliability and stability, and superior cost performance have been recognized by the majority of users, which is the pride of the national industry. At present, there are more than a dozen major DCS manufacturers at home and abroad. DCS procurement generally adopts bidding methods. Usually, users (or bidding companies) choose 3-5 for inquiry and bidding, and comprehensive evaluation and evaluation by experts, leaders and technical leaders. Finally, determine a model. There are many factors in the selection of DCS models, and it is not only possible to consider the amount of one-time investment. The principle of DCS model selection is as follows: select well-known companies with strong engineering strength, select mainstream models recommended by experienced experts, first consider the reliability, stability and operation convenience of DCS system, and secondly consider DCS function should be considered. To meet the "functional needs" requirements, with international advanced level (but not necessarily the most advanced), the system should have an open structure and flexible system scalability. Investigate whether the examples are used in the same industry, whether the effect is satisfactory, whether the manufacturer's backup support system is complete, investigate the manufacturer's engineering experience and implementation ability, the ability of professional solutions and design capabilities, whether the service is good, performance / price Whether the ratio is the best, whether the price is acceptable, whether the spare parts supply and response are timely. A factory enterprise DCS model is best to choose the same kind, easy to maintain and manage.

2. Evaluation content of the model

(1) Comparison of system hardware composition: 3-5 models participating in the inquiry will be compared with hardware configuration and function. The main items are as follows: operation station, engineer station, printer, host computer interface, auxiliary storage, network and internal communication, Field controller, on-site monitoring station, auxiliary cabinet (safety grid cabinet, terminal cabinet, relay cabinet, auxiliary operation console, etc.), application modules and power supply.

(2) I/O card capability comparison (each item listed: points/cards, card number, total points):

Monitor input 4~20mA

pulse

T/C

RTD

Control input 4~20mA

pulse

T/C

RTD

Control output 4~20mA

D/I button, switch status

D/O switch, relay output

(3) Comparison of system communication functions: standardization, openness and function of communication procedures, communication network (bus), communication speed, transmission distance, and network (bus) allow the total number of devices to be loaded, whether it is dual.

(4) Comparison with the host computer communication function

(5) Comparison of system software functions

(6) Comparison of after-sales technical services

(7) Comparison of application software tools

(8) Developmental, advanced (good, good, average, poor)

(9) The price is divided into the following items: hardware, software, spare parts, services (including training, materials, on-site services, technical consultation, etc.), hardware and software of the host computer, taxes and total prices.

3. Lessons learned

When choosing a model, it is best for the end user to decide according to their actual situation, and the opinions of the patent and design institutes (engineering companies) are used as a reference. Especially DCS, although the process equipment is complete, patent and design institutes (engineering companies) often choose the most powerful models for them, which are likely to be backward, high quality, and they do not consider the user in spare parts, maintenance, The need for networking and other aspects, if you choose, you can avoid this phenomenon. The DCS bidding of a device adopted the opinions of the end users, which not only saved more than 1/3 of the investment, but also selected a system with better performance. In addition, the practice of choosing trades based solely on one investment should be prevented. A device is only a cheap 6% price, bought a set of foreign DCS products that are backward, the future spare parts and maintenance costs will far exceed 6%. Because the DCS is updated very quickly, although the manufacturer can promise that the equipment will not increase in price within a certain number of years, it is difficult to cash.

Third, DCS system configuration

1, the work content of the system configuration

The development of DCS makes the system configuration more and more adaptable, and also includes the PLC control function, which can be realized from a small system of several or dozens of loops to a large system of several hundred or thousands of loops. The principle of system configuration should be to minimize the amount of hardware under the premise of meeting the production and control requirements of the device, in order to be economical and reasonable, and leave an appropriate margin. The system configuration work mainly includes the following aspects.

(1) System I/O point statistics: generally includes 10-15% of spare capacity. The case of hot spare and cold standby should be considered separately.

(2) Control station: All variables involved in control or important monitoring variables are considered to enter the control station. The type and number of I/O cards are determined by the number of I/O point statistics. The cabinet has 10% spare space. Redundant configuration of the main control unit, internal network redundancy configuration, control I/O card redundancy configuration, power supply redundancy configuration, estimated system load according to the standard scan period of 1 second to meet the specific requirements of DCS, considering the field transmitter power supply system and The association of DCS.

(3) Monitoring station: For systems with monitoring stations, some points that only need to be monitored can be considered to be in the monitoring station. However, monitoring stations are generally not redundant configurations.

(4) Operation station: Determine the number of operation stations according to the division of the process flow section or area and the number of operators in the central control room. At least two main operating stations with computer equipment should be equipped. The number of printers should meet the requirements of alarm, report and copy, but the printers for alarm and report must be separated.

(5) Configuration of auxiliary operation console: install flash alarm, indicator, handheld communicator, switch button, indicator light, terminal block, open, telephone, etc.

(6) Configuration of other stations or modules: According to the structure and function requirements of different systems, the engineer station, large screen, upper computer, etc. can be configured.

(7) Communication system configuration: Any network card, network cable (bus), switch, coupler, modem, etc. related to communication should be considered redundant configuration as needed. (8) System power supply and auxiliary cabinet configuration (safety grid cabinet, terminal cabinet, relay cabinet, distribution box, etc.): The UPS uninterruptible power supply capacity is 40% higher than the DCS system required capacity, and the power supply can be continued when the power grid is out of power. minute. According to the site hazardous location, the safety barrier model is recommended.

(9) Spare parts and consumables, in principle, must be prepared for two years.

2. Experience and lessons

The system hardware configuration is directly related to the investment, application and maintenance of DCS. Some unnamed small bidders or agents have adopted unfair competition in order to win the bid or the configuration proposed according to the general standard does not meet the requirements of the end user. For example, a certain device is provided by the agent DCS. There is basically no redundancy. After one year of production, the process equipment needs to be increased. The reordering costs a lot of money, and the ordering period is long and the operation is delayed. There is another tendency, a system is introduced by the end user itself, the hardware configuration is more than 30%, resulting in a backlog of funds. Both extremes should be avoided. For new installations, the amount of redundancy should be appropriately larger. If it is modified, it can leave less margin.

The operation station should not be configured too much. If the operation position is divided according to the habit of using the conventional instrument, after the operator is familiar with the operation for several months, there will be an operation station that is not used. But it can't be too small, for example, the configuration of a system foreign company, thousands of points of process input and output, hundreds of circuits are only configured with three operation stations (5 CRT), can not be spare each other, under normal circumstances can also be reluctant Coping, but it is particularly difficult to wait until a process emergency or DCS partial failure.

Unnamed small bidders or foreign agents are generally poor in terms of after-sales service, slow in response and high in cost. Well-known domestic DCS manufacturers attach great importance to engineering services and after-sales response, timely and convenient, satisfactory and reliable, spare parts supply is no problem, can reduce spare parts inventory without affecting the production of driving. In addition, it is recommended to use the same model DCS in one enterprise.

Fourth, the establishment of the system use environment

1, the work content

In the DCS application work implementation step, the establishment of the use environment is a very important task. It is the guarantee for the normal operation of the DCS, including the following aspects: the determination of the position of the DCS control room, the determination and control of the DCS control room and the auxiliary room. Indoor equipment location and building requirements, lighting requirements, anti-jamming measures, grounding requirements, power supply requirements and isolation requirements.

The DCS environment requirements can be determined by referring to GB2887-82 "Technical Requirements for Computing Station Sites" and the relevant technical specifications of DCS manufacturers.

The design institute shall design according to the above requirements, select the construction unit, and generally choose the special computer decoration professional team to ensure the quality of the interior decoration, air conditioning, lighting, etc. It is necessary to invest more in the DCS environment.

2. Experience and lessons

The environmental problem is the premise of ensuring that the DCS can continue to operate normally for a long period of time. In these respects, it will cause various hazards to the normal operation of the equipment. For example, if the temperature is too high and there is too much dust, it is particularly likely to cause breakage and flopping of the hard disk spring reed. The foreign DCS system in a device is continuously broken for two reasons because of this reason, and the spare parts cannot be placed in time. More than half a year. Because of the high temperature, memory and auxiliary memory are not working properly, and system turbulence has occurred in multiple systems. If the temperature is too high, the threat of static electricity will cause some DCS to crash. If the operator does not pay attention to this problem, the electrostatic discharge will cause the card or module to malfunction, and it will affect the process operation. Grounding is also an important and difficult problem. In the process of installation and debugging, several mainstream DCSs in the market have had various bad consequences caused by poor grounding.

In short, we must create a good application environment for DCS.

In the layout of the DCS, it is best to consider adding a buffer room and then entering the central control room or machine room. This is a good measure for dust prevention. For dust-proof conditions, a clean room (such as a disk cleaning room) can be added. The spare parts library, the media library, and the hardware maintenance room are all equipped with air conditioners. Although some DCS manufacturers advocate that their products have good adaptability, it is found that in actual use, it is impossible to use air conditioners (affecting product quality and DCS service life). .

In the computer room and the central control room, do not add heating, especially do not add plumbing. In the case of installing the raised floor and cable trenches, special attention should be paid to avoid accidents such as leakage of water, steam leakage, intrusion circuits, flooding of cables and equipment. .

V. Staff training

1, the work content

After the hardware, software and usage environment of the DCS is determined, personnel training is a key work for DCS. It includes the following aspects.

System Engineer Training: A DCS must train at least one system engineer to be responsible for the overall technical leadership of the system and the organization of the project manager, and to have a comprehensive understanding of the DCS system.

Configuration design, configuration generation software engineer training: DCS best application software is done by the user or involved, the seller provides technical guidance. This kind of training has the best effect, and it is the prerequisite for the improvement, modification and continued development of the system application software in the future. In this respect, the designer and the factory user (instrument self-control and craftsman) usually send engineers to train at the same time, and should be factory-owned. Mainly.

Training of PC and DCS interface hardware and software engineers: If the DCS configuration PC or MES system should be trained separately, personnel can be selected from the enterprise information center, production scheduling management, and computer personnel.

Training of hardware maintenance engineers: Most of the modern DCS hardware maintenance is board level or module maintenance, and the system has diagnostic functions. Therefore, hardware maintenance personnel generally do not train separately, but some software engineers can focus on training.

The training of the above four kinds of personnel generally needs to be carried out in the manufacturing factory. Before training, it is best to self-learn and read the relevant technical materials, and be fully prepared to achieve satisfactory results. Those with certain DCS foundation and application experience are better.

Operator training, workshop directors and training of relevant leaders are also very important tasks. This part of the training is conducted by trained computer personnel lectures and hands-on training. First of all, the trained personnel should prepare the operation manual for the workshop operators, and carry out the actual machine training according to the technical team. Generally, they can be mastered very quickly. It is a good idea to set standards and requirements before you go to work.

2. Experience and lessons

The training work is related to whether the user can master the system and whether it can undertake the tasks of system maintenance, improvement and modification, participation in commissioning and further development. It is necessary to avoid some deviations in training, such as DCS training business trip as an internal relationship care and balance, sending unrelated personnel to participate in training; such as the introduction of DCS with the device set, only process training and design training, not arranged for DCS manufacturing The training of the factory, some in the configuration design training did not arrange for the end-user technical staff to participate, and some of the dispatched training personnel did not engage in DCS, and did not do DCS pre-training, in the short-term DCS training, little gain. Some do not have a complete concept of the system to be studied before the training, and are not prepared for the problem. They are not suitable for foreign question-and-answer training methods. In some trainings, the emphasis is on the basic work related to the start-up work, ignoring the application software and the knowledge required for further development in the future. These have caused difficulties in application maintenance and development, and the application software that is purchased at a high price cannot be used correctly and comprehensively. .

The operation of the DCS is generally simple and convenient, and it is easy to learn. It is not necessary for the process operator to talk about the complicated computer principle and internal structure, and to emphasize the practical use methods and operation requirements. The well-known domestic DCS is generally Chinese, there is no language problem, but the introduction of foreign DCS with Chinese characters is not much, mainly in English display and printing, which has a certain gap with the English level of our operators, for the display and print content. In particular, a large number of abbreviations do not understand, memory is difficult, affecting the use of DCS, this is the key in the training of process operators.

Sixth, system configuration and generation

1, the work content

The core work of DCS applications is system configuration, including hardware configuration configuration and system application software configuration. The hardware configuration configuration first completes the system configuration diagram, including the configuration diagram of each card to determine the address or point name, this work must be completed before the application software configuration.

Each DCS application software configuration method will not be exactly the same, each has its own characteristics and advantages and disadvantages, the development trend is to configure an independent configuration workstation or engineering station. Some DCS manufacturers have also developed a microcomputer configuration system software that allows most of the application software to be configured on a PC and then converted to a form acceptable to the system. There have also been new developments in configuration software, such as the process of accelerating the configuration of CAD.

There are three key steps for DCS application software configuration work.

(1) Configuration design

Firstly, the basic requirements of the automatic control system and the configuration requirements of the distributed control system should be scientifically organized according to the system objectives, and finally the configuration source files are formed. Including the following parts: system configuration design, directory (DIRECTORY) and file (FILE) organization design (some systems can not be done), monitoring station configuration design, control station configuration design, operation station configuration design, and Configuration design of other network devices.

(2) Fully understand the configuration methods, techniques and system functions of DCS

For the training of DCS configuration methods, techniques and system functions, we must thoroughly understand and understand. Only in this way can we fully play the role of DCS, and the system configuration can meet the requirements of practicality, convenient operation and strong functions, and through practical application and discovery. Insufficient, gradually improve and modify the configuration design.

(3) Consultation, meeting process requirements, combined with operation and maintenance experience

The DCS is for the process and is ultimately used and operated by the process. When configuring DCS, it is necessary to consider and consult the process requirements. It is best for process technicians to participate in the process, strive to meet the requirements of process operation, focus on accumulating daily process operations and instrument maintenance experience, turn these experiences into application software, and fully exploit DCS. Advanced control and operation functions to improve the utilization of DCS.

2. Experience and lessons

The configuration and generation must be attended by the end-user technicians. Depending on the strength of the user, the depth of the configuration design intervention is determined, and the best generation is done by the end user. Many systems are configured by designers or DCS manufacturers. The end users don't care. If the designers or DCS manufacturers are not familiar with the process production operations and do not understand the operators' requirements and habits, the standard software problems are not big. Content rework, such as reports, screens, and operating methods, which are closely related to the craft, is indispensable. Conversely, if the end user's craftsman and the instrumentation supervisor with practical production experience assume the design configuration or participate in the design configuration, the situation is quite different. The report and screen made by a system according to the requirements of the craftsman are very popular, and the control scheme combined with the actual design is simple and easy to implement, and the application effect is good.

A lot of successful experience shows that the user can participate in the design configuration, and the theory can be combined with the actual to make a relatively successful configuration design and configuration generation. Many companies rely on their own technical strength to complete DCS configuration design and configuration generation, and their own design, installation and commissioning, construction and maintenance development, created a good path.

Seven, installation and commissioning

1, installation work content

Before the DCS is installed, the following conditions should be met: the machine room and the central control room are completely renovated, and there is no need to dig trenches and holes to generate dust and vibration. The raised floor is paved, the floor is clean, the air conditioning system is put into use and has passed the assessment. UPS commissioning assessment is qualified, some conditions can not be met and temporary power supply debugging, but should be added with voltage regulator equipment. The lighting construction is completed and normal operation. No vibration or electrical interference is allowed in the vicinity of the equipment room. The grounding system is completed and iteratively checked to confirm that no interference signal will be introduced.

System installation work includes: cabinet in place, equipment (host, monitor, printer, etc.) installation, card or module installation, system cable, internal cable connection, terminal external instrument signal cable connection, system power supply, ground connection Wait. These tasks are generally completed by the user under the guidance of the DCS manufacturer.

System installation should be performed in accordance with the installation requirements of the specific system. When installing in winter, it should be noted that the temperature gradient from the warehouse to the machine room meets the requirements of the system, and the equipment room can adopt measures to gradually increase the temperature to meet the requirements.

When the installation work is over, the general DCS manufacturer sends engineers to the site for inspection and power-on, and then can debug the system according to the debugging scheme.

2, debugging work content

(1) DCS single machine debugging and system debugging

A] Hardware debugging check and single machine debugging: each device passes diagnostic program, standard function test, power card voltage measurement and inspection, I/O card zero point, range and precision debugging check, signal adjustment card zero point, range and accuracy Debug check. Some DCS have special calibration instruments.

B] Function check and debug: System standard functions, including communication, display, printing, etc. User screen inspection, automatic format report check, control scheme check and debug, interlock logic sequence control scheme check and debug, other user-configured program check.

(2) Joint adjustment of DCS and the scene

Instrument input signal joint adjustment, DCS output and actuator linkage, joint interlocking function, and sequence control.

Debugging is a scientific and meticulous work, and it is a reliable guarantee for the commissioning of the system. For this reason, there must be a debugging plan, and the organization of the debugging, the standardization of the debugging records, and the signature of the debugger and the acceptance person, complex The interlock protection and sequence control functions must be signed by the person in charge of the process.

(3) On-line debugging of advanced control or optimization control application software after driving

This commissioning must be carried out after the process unit has started smoothly. First, a commissioning plan should be developed to ensure the smooth and safe production of the process. Repeatedly adjust P, I, D and other parameters, so that the control system and interlock protection are put into automatic state to achieve the desired use effect. Through debugging, the training operator grasps the application method and understands its working principle and precautions.

3. Experience and lessons

The internal installation wiring and debugging of DCS equipment is best undertaken by the end user's instrumentation and process personnel. This is most beneficial for understanding the system situation, mastering the system's advantages and disadvantages, and doing future maintenance and development and daily operation.

In the process of function debugging and system joint debugging, it is not just a matter of DCS manufacturers. User process operators must participate. Instrument self-control personnel must participate. The relevant personnel of the construction unit must participate and cooperate.

Before powering up, it is necessary to check the voltage waveform, frequency and grounding of the UPS, and check the setting of the DCS board switch. It is best for DCS factory engineers to take charge of this work. There have been cases of burning out multiple power cards and equipment due to the high supply voltage, and there have been accidents caused by the board being inserted into the wrong position. The power supply of equipment in the United States, Japan, and Western Europe is generally 110V, and China requires 220V. Some DCSs now have 110V and 220V switches. Some do not pay attention to the supply, and have not carefully checked them. Add 220V to the 110V device. Cause damage.

Before connecting the field signal line to the DCS terminal, it is necessary to measure its insulation resistance and check for abnormal interference signals, especially before the construction of the new device is completed, it has been burned out due to the introduction of a welding machine or electrical strong interference signal. Safety barriers, modules, because of the grounding of the primary table, the accident has also occurred.

During the hardware test, all spare parts must be thoroughly inspected to ensure their good standby status.

During the testing process, special attention should be paid to the preservation and dumping of the modified content. Generally, after the end of the day, the copy must be copied. Otherwise, the content is easily lost due to multi-person operation.

Eight, commissioning and assessment

1. The operation of the system

System commissioning generally refers to the device driving DCS into operation. The DCS must be put into operation in the following conditions:

(1) The system is jointly adjusted.

(2) The system environment, such as the air conditioning system, UPS power supply system, and grounding system, operate normally, meet the technical standards, and pass the acceptance.

(3) The DCS maintenance personnel will pass the actual commissioning work and pass the examination, and receive the employment certificate.

(4) The process operator and the workshop director are qualified for training and receive the employment certificate.

(5) The system spare parts are in standby state after being debugged.

(6) DCS operation manual, fault handling manual and other materials are sent to the hands of operators and maintenance personnel.

(7) On-site service of experienced engineers and technicians of DCS manufacturers.

2, system assessment

The evaluation time of DCS is best selected after the normal operation of the process equipment, generally 72 hours. The guaranteed value is as follows: the operating rate of computer module is 99.95%, the operating rate of DCS is 99.99%, and the calculation method of operating rate:

Operating rate = (assessment time - accident time) / assessment time

3. Experience and lessons

Before the DCS is put into use, the preparation must be carried out in advance. In the general enterprise, the process equipment is placed first.

The evaluation of the DCS is carried out after the process is started. Because it is not in normal operation, the function of the DCS cannot be fully expressed, and the actual load cannot be reflected. For those systems that are designed to load the card, the problem is not exposed. Some systems run normally before driving, and after driving, they show insufficient capacity, insufficient speed, small processing capacity, and even crash due to too much load. If the design is reasonable but the indicators provided by the system itself cannot be achieved, it should be the responsibility of the DCS manufacturer. DCS is a product of high technology, a combination of multiple technologies and multiple disciplines, and the development speed is particularly fast. The improvement in DCS application level lies in the development of advanced and optimized control software. This technology is complex, difficult and requires a combination of forces. Due to these characteristics, it is decided that it is impossible to do the application of DCS without a corresponding management system. According to the specific situation of each enterprise, the management organization does not have to insist on reunification. However, it has established a special management organization to uniformly plan the DCS application plan of the whole plant, uniformly consider the selection of DCS models, and uniformly arrange the reserve, ordering and localization of spare parts. To meet the urgent needs of production, reduce inventory backlog, unified design of integrated control and management information systems, unified training and horizontal integration, and development of high-level control software, has become the trend of the times. Some enterprises have set up special process computer offices or other institutions to manage the process computers of the whole company (the main plant), breaking the past, the various devices are not ventilated, and the models purchased are various, and the islands are automated. Spare parts cost up to tens of thousands, a few million yuan of decentralized situation, straighten out the relationship, and develop very quickly.

In addition to program management, DCS management should also have application management and project maintenance management. The project management needs to determine the composition of the personnel in the design, construction and commissioning phases of the DCS, the scope of the division of labor, the establishment of inspection and acceptance standards at each stage, and the organization of on-site inspection, assessment and acceptance.

DCS maintenance management first needs to establish relevant rules and regulations and procedures, such as: process computer maintenance, overhaul, management system, technical management system, equipment, spare parts management system, job standards, hardware equipment assessment methods, software investment rate assessment method , safety management system, regular meeting system, maintenance procedures. In accordance with the established system, strengthen the management of the company's (general plant) process computer, establish the necessary incentive mechanism, mobilize the enthusiasm of maintenance personnel, and give full play to the role of DCS.

1, system maintenance

After the system is properly checked and accepted, it will be transferred to normal operation. The task of system maintenance will be mentioned on the agenda.

(1) Maintenance work can summarize the following points: system health check, system environmental condition check, parameter and configuration modification, fault and equipment defect handling, fill in relevant records, spare parts and repair tools, instrument storage, system equipment And workplace hygiene.

(2) Maintenance team can establish the following records: handover record, system operation status record, regular maintenance and maintenance record, software maintenance record, safety record, accident hidden danger, accident and illegal operation record, fault and equipment defect record, spare parts Spare parts management records, foreign personnel registration records.

(3) Development of hardware localization: Imported DCS also has its unfavorable side. Spare parts are generally expensive, emergency response and response are very slow. Practical experience tells us that it is impossible to rely on imports for a long time in maintenance work, and the models are eliminated. The speed is also very fast. In this respect, we should first base ourselves on the domestic market and localize some wearing parts. Some enterprises set up special research groups to realize the replacement of imported products with domestic products by printers, keyboards and I/O cards. Some enterprises cooperate with colleges and universities and research institutions to realize the localization of major card parts, which are the direction of DCS maintenance work.

2. Continued application development of system application software

The application development of application software is often the most basic function when the system is first used. The focus of this phase is to coordinate the relationship between various aspects and make DCS work on schedule. The personnel involved in the work need a process familiar with digestion and absorption. The craftsman should have a process of operating habits. Generally, after the system is put into use for one year, the work of the application software to continue development will be mentioned on the agenda. The content is as follows: The software further digests and absorbs, further modifies and supplements the first version of the application software, such as modifying the picture, improving the picture that is more important for production operations, modifying the control plan, etc., developing advanced control software, improving economic efficiency, and developing Device production management functions, development of local optimization or full device optimization or full device optimization software, the entire plant MES system networking, to achieve functional development. In this work, we must first train the application development technology, and at the same time integrate the technology, instrumentation, computer technology and professional knowledge. Generally, a research team will be set up under the organization of the higher authorities. Developed in cooperation with universities, research departments and DCS manufacturers in order to get the best economic benefits as soon as possible.

In summary, the application of enterprise DCS, truly do the above ten tasks, can fully play its role, become an important guarantee for enterprises to achieve "stable and long-term" production, achieve significant economic benefits, and for management information The establishment of the system and the establishment of the MES laid a good foundation.