Application of Configuration Control in Concrete Mixing Plant System

1 Preface

Concrete mixing plant is a "conventional weapon" for national infrastructure construction. Its advanced level marks the level of a country's construction manufacturing industry. Foreign concrete mixing plants embody mechatronics technology. Their micro-control technology is mature and reliable. The material ratio and capacity change control are very accurate. Some have also added mixer dynamic load monitoring, concrete material consistency control, dust removal, noise reduction, wastewater treatment and other devices. Concrete pumping technology is becoming more and more mature, with the maximum horizontal pumping distance reaching 4000m and the pumping volume reaching 180m3/h. China's concrete mixing plant has gone through the development process of introduction-absorption and digestion-partial domestic-all domestic-improvement and improvement, but there are overall shortcomings such as uneven technical level, low new technology content, low penetration rate,
large regional differences, low degree of intelligence and low environmental protection performance. The gap with foreign countries is becoming more and more obvious, so the study of the control of concrete mixing plants has a broad application prospect and theoretical scientific value.

This paper studies the use of MCGS embedded version industrial configuration software to draw dynamic monitoring panels on the upper computer, and the use of high-performance embedded integrated industrial computer Kunlun Tongtai nTouch TPC064-TB33 touch screen on the hardware control panel to form an embedded control system for concrete mixing plants. The lower computer is controlled by PLC, and through the communication between the configuration software and PLC, the full automation control of the concrete mixing plant is realized, and the real-time display of the system operation status, report display, diversified alarm, digital calibration, recipe management and other functions are completed.

2 Hardware composition structure of embedded control system of concrete mixing plant

According to the production process and control requirements of the concrete mixing plant, the control system of the concrete mixing plant should measure and mix aggregates, cement, water and admixtures to achieve intelligent, multi-functional, safe, efficient and fully automatic control, which can not only automatically control and monitor the production process of the concrete mixing plant, but also realize data management of concrete production.

The specific control principle of the concrete mixing control system is (1) Upper computer control: realized by the full Chinese embedded version of industrial control configuration software MCGS and touch screen. The upper computer part is the command center of the entire production, controlling instruments and PLC, and monitoring the entire production operation at the same time. The upper computer part realizes the functions of human-computer dialogue, inputting production parameters and user parameters, reading information from the lower computer for monitoring, fault alarm, controlling printer to print data, storing data, and realizing the export of touch screen data to the computer for long-term storage. (2) Lower computer control: The Japanese Mitsubishi PLC realizes the real-time automatic control of the concrete mixing plant, receives information from the upper computer, and outputs the control intermediate relay after logical judgment through input signals. The 24V DC power supply is used as the isolated power supply for the output and input intermediate relays. The control instrument and PLC are both under the command of the upper computer. The instrument is mainly responsible for controlling the production according to the formula, triggering the corresponding intermediate relay action, and controlling the batching process; the PLC is mainly responsible for the entire production except batching.

3 Software Development of Embedded Control System for Concrete Mixing Plant

3.1 Selection of Operating System and Application Software

In order to realize the application of embedded systems in the field of concrete mixing plants, the operating system selected is the latest embedded real-time operating system windows ce.net launched by Microsoft. It includes everything needed to create a customized device based on Windows CE, with complete operating system features and an end-to-end development environment, powerful networking capabilities, strong real-time performance, small memory footprint, and rich multimedia and web browsing functions. The application software selected was the MCGS embedded configuration software launched by Kunlun Tongtai Automation Software Technology Co., Ltd., the pioneer of domestic embedded configuration software. MCGS embedded configuration software is based on the real-time multi-tasks operating system (RTOS). The architecture is divided into two parts: the configuration environment and the operating environment. The configuration environment is equivalent to a complete set of tool software that can be run on a PC. It uses a simple modular design to help users design and construct their own application systems. The configured application system is downloaded to the embedded operating system Windows CE through a serial port or Ethernet and runs in real time. The operating environment runs in the user-specified manner according to the configuration project constructed in the configuration environment, and performs various processing to complete the goals and functions of the user's configuration design. The two parts are independent of each other but closely related. After long-term actual operation on site, the system has good stability and high reliability, creating good economic benefits for users [1].

3.2 MCGS configuration software development system operation monitoring interface

The operation diagram of this system uses three-dimensional animation, timely simulation operation, intuitive and convenient, and simple operation. Recipe editing and production parameters (drop value, small investment value, PLC parameters, instrument parameters) appear in dialog boxes, which are very convenient for viewing and modifying data. The production data management system provides production date, user name, two query methods, data statistics and data backup, among which data statistics can count the consumption of consumables. User information can input and manage all user information for production. System debugging allows users to debug the system lines. The operation monitoring interface of the embedded control system of the concrete mixing plant is shown in Figure 1. Users can select the recipe, modify the tank volume ratio, produce cubic meters and edit the bill of lading parameters in this screen, display the execution status of each mechanism, and control the operation of the entire concrete mixing plant.

The order number in the operation diagram is automatically generated by the system, 10 digits, the first 6 digits are the system date, and the last four digits are the serial number. The order number in the production data browsing report is incremented. If semi-automatic production is required, turn the knob to the "semi-automatic" gear (middle gear), and then press the "automatic measurement" button. The system will measure the material according to the formula set in the instrument. After completion, press the "automatic feeding" button. After the feeding is completed, press the "automatic concrete output" button. In the event of a fault in the upper computer or special production requirements, production can be controlled in a semi-automatic state.

Click "PLC"/"PLC output test" on the main menu to enter the PLC output test interface. Follow the Chinese markings on the buttons. When the button that matches the corresponding device in the flowchart is pressed, the button changes from purple to blue, and the corresponding status indicator light changes from red to green. The relay controlling the device is in the on state. The output wiring of the system can be judged to be correct or not according to whether the device operates accurately. [3] The operation diagram is shown in Figure 2, and the setting and modification of PLC parameters are shown in Figure 3:



The connection between the control system and the external hardware device PLC is established in the MCGS device window, which enables the system to read data from the PLC and control the working status of the PLC, thereby realizing real-time monitoring of the industrial process. The method to realize device driving is to set relevant properties according to the type and characteristics of the PLC, encapsulate the device operation methods such as hardware parameter configuration, data conversion, and device debugging in the component, and establish a data transmission channel connection with the PLC in the form of an object. During the operation of the system, the device components are uniformly scheduled and managed by the device window. Through the channel connection, they provide the real-time database with data collected from the external device, query the control parameters from the real-time database, and send them to other parts of the system for control operations and process scheduling, thereby realizing

real-time detection of the working status of the device and automatic control of the process. Through the implementation of the above design scheme, the system has completed rich and vivid multimedia screens, diversified alarms, digital calibration, common parameter settings, system debugging, automatic water addition and subtraction, and report functions. It has digital display, query, analysis, statistics, printing and other functions, as well as formula management functions, which can store more than 100 formulas; perfect security mechanism, users can set different operation permissions according to different levels of management personnel; full automatic/semi-automatic/manual switching is convenient and other functions.

4 Conclusion

The content of this article is part of the concrete mixing plant control system project. The new industrial control technology is used to solve the key technology of the communication between the upper computer configuration software and the lower computer PLC, which is a new development direction of the concrete mixing plant control system. The system solution has achieved the expected effect, with strong practicality, high security, friendly monitoring interface, convenient operation, and reliable operation. It has been successfully tested and mass-produced in Liaoning Fuxin Hengtai Machinery Co., Ltd., the drafting unit of the national standard concrete mixing plant technical conditions.

The innovation of the author of this article is to solve the key technology of the communication between the upper computer configuration software and the lower computer PLC, realize the first application of industrial control technology in the concrete mixing plant control system, and achieve intelligent and multi-functional full-automatic control.