The application of WinAC in the automation system

Application of WinAC in the automation system of thousand layer crisp production line

Abstract: WinAC is the latest industrial automation control system based on PC launched by Siemens, which has the characteristics of PC's powerful computing function, data processing ability, PLC logic measurement and control and operation reliability. This paper introduces the successful application and unique characteristics of WinAC in the automatic production line of thousand layer pastry

key words: 1000 layer crisp oven based on PC automatic distributed control system process control system

overview

the total length of 1000 layer crisp production line is about 200 meters, which is mainly composed of the following units:

1 laminated crisp

laminated crisp machine is the first important process of producing biscuits, and vertical or horizontal can be selected according to different plants. It includes seven rolls, three times of rolling, and is equipped with a pastry spreading machine. The automatic control system is required to meet the following requirements:

· the transmission control adopts vector frequency converter for speed regulation, and the linear speed synchronization has high stability

· roll gap is controlled by digital closed-loop adjustment system, which is simple, convenient, fast and efficient

· the man-machine interface control can realize linkage control with the relevant parts of other molding hosts, and the operation is simple and convenient

· the stacking times and width can be adjusted arbitrarily within the range

· lamination width mm

· stacking times

· tablet thickness 0 MM。

2 feeder

the feeder will transport the mixed tough biscuit blank to the double rolling mill of the next process after preliminary rolling. The electric control system requires synchronous speed regulation control, manual adjustment and automatic operation control

3 double rolling mill

this equipment is used to roll the surface germ sent by the stacker or feeder for many times, so that the surface germ becomes thinner from thick. The requirements of the electric control system:

the roll adopts frequency conversion speed regulation control, with synchronous speed and stable performance

accurately control the skin thickness, and use intelligent digital meter to set and display

4 ovens

there are hot air circulation ovens, far infrared ovens, heat transfer oil ovens, etc

the biscuit baking oven is an important part of the biscuit production line, which is composed of electrical control system, hot air circulation system, heating system, smoke exhaust system, furnace conveying device, furnace automatic detection and tensioning device, etc. the automatic control system is required to achieve the following functions:

real time monitoring of the working state of the production line

temperature coordinates, temperature rise curve and other displays

parameter correction of temperature regulation system

historical working state record preservation

high temperature control accuracy, convenient operation, stable operation, high efficiency and reliability

the hot air circulation system adopts automatic control of hot air volume, closed-loop control, and automatic functions such as natural and mandatory smoke exhaust can be selected

various safety protection functions such as under pressure, over pressure, gas leakage and over temperature of gas furnace

5 molding machine

the molding machine is composed of multiple mills and transmission units, and there is no mechanical transmission interlocking between them. Tension free detection unit requires the whole production line to run synchronously through the speed of the electrical control line, which is difficult to control and has high requirements for the functions of the automation system

II. Characteristics of control system

to sum up, the control system of Qianceng crisp production line is an integrated automatic control system integrating motion control and process control, which should be summarized as follows:

distributed: the total length of the production line is about 200 meters, and there are many and scattered control points, so the distributed measurement and control system is the most suitable. The distributed measurement and control system has the advantages of less wiring, strong interference ability, convenient expansion and maintenance, safe and reliable operation and minimum failure risk

bus: the whole line adopts field bus network control, eliminates the interference factors of a large number of analog signals, and realizes accurate speed coordination control and high-precision temperature measurement and control detection, which is consistent with the control

large amount of formula storage: a production line can produce hundreds of products, so there is a large amount of formula storage and call. Due to the influence of memory, ordinary PLC controller is difficult to store and call a large number of formulas, so PC based automation is the preferred scheme of this system

centralized management: distributed control and centralized management are the characteristics of modern process control system. This system is equipped with perfect man-machine interface operating system, comprehensive system monitoring and abnormal alarm function

motion control: speed synchronization is also the key of this control system. Vector converter is used to achieve the coordination and unity of full speed through master command control

III. PC based automation -- WinAC

WinAC is the latest PC based automatic control system launched by Siemens company. WinAC has the function of PLC, but it is different from ordinary PLC controller. It has powerful calculation function, data processing ability and calculation speed unmatched by PLC, and takes into account the operation reliability characteristics of PLC. Its massive memory is especially suitable for large amount of data calculation, large amount of formula storage and management. Its calculation function is the same as that of PC, and its reliability and function can be compared with that of PLC-S system. It is the most ideal choice for the control system of thousand layer pastry molding machine and oven mechanical equipment:

progressiveness

WinAC is a PLC controller based on the standard Windows operating platform, with ladder diagram programming, so it has independent and strict timing control. It especially meets the control tasks of high-speed, accurate, complex calculation and strict time requirements

winac supports OPC, active X and DCOM technologies under standard Windows NT. Control and communication kernel and so on. Once problems are found, they should be handled in time; The communication of standard Windows NT tasks is completed by its built-in proxy server, so it is more powerful than ordinary PLC controller

application development environment

siemens unified configuration software step 7 is the standard development platform of WinAC controller, including communication configuration, programming, testing and startup, as well as the preparation of system documents. Engineers who are familiar with step 7 do not need to occupy additional training time

open interface

winac provides standard OPC control interface and active X control interface, which provides great convenience for our application

system configuration interface

opc process control ole is an international standard for automatically accessing data through Windows NT applications, and it is also a standard feature of WinAC. The OPC server can access the process data in the control driver; The active X control interface accesses process data directly from ole standard applications without programming. This function makes it possible for us to enter with a low threshold, so as to carry out more complex application development with the help of high-level language Visual Basic in software development

calculation function

winac provides powerful calculation function and establishes a working data link with industrial process data. It enables the upper computer to process process process data in real time, complete complex measurement control and fault analysis and calculation, and create its own HMI front end in visual basic or do statistical analysis in well-known excel. Manage the flow of data information between process control and PC applications, allowing efficient and easy access, display and modification of process data. For the process control system with large data processing capacity and high memory requirements, the general PLC controller is not competent for the work, which can be easily solved with WinAC. This is the reason why we choose WinAC, and Siemens provides us with a suitable and economical solution

IV. system principle and structure

the whole system forming machine has a total of 18 units. Each unit is equipped with a td-200 and cpu224 controller, which are used for the measurement and control of the machine's running speed and dough thickness, as well as parameter display and given setting. Among them, the PLC of 9 dough mills also controls the dough thickness, realizing the closed-loop control of dough thickness. 18 PLCs and 18 frequency converters are distributed in the whole production line. All control equipment is equipped with -dp communication interface board. Through a highly reliable Profibus-DP Field Bus Group, a unified network structure, distributed control system and convenient local control and operation are realized

except that each unit can set parameters and monitor operation data separately, the control area of the molding machine is equipped with a touch human-machine interface, which is responsible for the real-time monitoring of all equipment in the molding area through the PROFIBUS-DP network. A 15 inch screen computer is set in the oven area to conduct man-machine operation and monitoring, man-machine dialogue, data storage, report printing and production management of the equipment of the whole production line through PROFIBUS-DP

the main controller of the whole production line is the central controller WinAC, which is responsible for the main control of the production line, PROFIBUS-DP network management and network server. The software core and recipe database of the control system are completed by WinAC controller. In order to avoid the unpredictable impact of report printing and human operation on the control system, the system adopts the hardware controller wbc416 developed on the basis of software WinAC control system. In addition to preserving the advantages and characteristics of PC based automation integrity, it also has the characteristics of solid design, strong scalability, solid shell design, electronic hard disk, and fan free structure. The overall structural design aims at high protection against vibration and impact. The integrated interface: USB, 10/100m Ethernet interface, profibus-dp/mpi industrial fieldbus system not only casts the status of its main controller, but also ensures the high-grade and perfection of the system

dough thickness control system of dough mill

dough thickness measurement and control system is a closed-loop real-time monitoring system composed of grating sensor, PLC and stepping motor

the skin thickness is detected by ka-300 grating, and the detection accuracy is 0.02mm

the thickness feedback value is processed by PLC, and then the PID calculation is carried out and the stepping motor is controlled to form a closed-loop control system, which eliminates the large loss risk of the enterprise, except for the accumulated mechanical error

the closed-loop control system can correct the thickness in real time and improve the product quality

five phase stepping motor step angle 0.72o output frequency 9KHz,

v=1.95 a=0.75 n.m=0.45 (4.5 kg force)

oven temperature control system

oven temperature is divided into 8 areas, each area temperature is a closed-loop measurement and control system, and is equipped with intelligent algorithm, the control accuracy can reach +1oc

special thermocouple module for temperature collection, surface temperature and bottom temperature are controlled respectively

control the SCR power regulator to control the temperature

the input signal of SCR power regulator is 0-10V, and the output power can be continuously adjusted. There are eight three-phase balanced power regulators in total

the chimney in the temperature zone adjusts the opening according to the formula to control the flow

automatically detect and adjust the steel strip slipping

intelligent closed-loop control algorithm, adaptive parameter setting function

the central control station can set and monitor the temperature

v. functions realized by the measurement and control system

Chinese dynamic man-machine operation interface, dynamic display of equipment operation status, real-time display of electrical parameters and process parameters, with the functions of real-time curve display, historical curve display, large-scale dynamic standard database, providing annual and monthly reports and random printing reports

the start/stop of field equipment can be monitored and controlled through the central monitoring station to intervene in the production process

pop up menu mode for parameter setting and change: including speed setting, temperature setting, thickness setting, order change, order parameter setting, and can be transmitted to the PLC unit of the field controller to change process parameters and control process

formula parameter setting: hundreds of formulas can be set according to production needs, so that many frontlines can become a reality

beautiful three-dimensional dynamic equipment graphics and process operation diagram interface

automatic operation, computer remote control operation

built in database: Yes