An automatic monitoring system for a fluidized bed incinerator was successfully developed by constructing a multi-point interface (MPI) network using an S7-300 series programmable logic controller (PLC) and other hardware, and establishing communication between the PLC and the host computer through the industrial control configuration software MCGS and MPI. Actual operation has proven that the system is accurate, reliable, and performs well. 1. Introduction With the increasing level of industrial automation, the use of programmable logic controllers (PLCs) is becoming more and more widespread. PLCs are favored for their high reliability, ease of operation, flexibility, and low requirements for the field environment. However, PLCs as standalone monitoring systems have limitations, mainly manifested in their inability to store large amounts of data, display various real-time and historical curves, display Chinese characters and print Chinese reports, and lack of a user interface. With the rapid development of computer technology and the emergence of industrial control configuration software, the shortcomings of PLC control systems have been compensated for. Computer monitoring systems widely used in industrial fields, developed using industrial control configuration software, are characterized by a computer acting as the host computer in the monitoring system, while the slave devices often use PLCs as field-level control devices for data acquisition and control. The host computer utilizes industrial control configuration software to store, process, and analyze the acquired signals. It monitors all equipment in the system in real-time via a screen display, showing real-time parameters and allowing for intervention and control during operation. MCGS industrial control configuration software, developed by Kunlun Tongtai Computer Research Institute, fully considers the specific conditions of the domestic industrial control field, absorbs the advantages of similar foreign products, and boasts strong versatility, high quality, and low price, making it one of the excellent domestic industrial control configuration software programs. It is currently being applied to the automatic control system of a fluidized bed incinerator. 2. Main Functions and Characteristics of MCGS MCGS is a configuration software system based on Windows 95/98/2000/Me/NT operating systems, used for quickly constructing and generating host computer monitoring systems. It provides users with a complete solution and operating tools for solving practical engineering problems, from device drivers and data acquisition to data processing, alarm handling, process control, animation display, and report output. MCGS configuration software has multi-tasking and multi-threading functions. Its system framework is programmed in VC++ language and provides VB programming interface to users through OLE technology. It provides rich device driver components, animation components, and strategy components, and users can easily expand the system's functions at any time. The main features of MCGS are as follows: (1) Comprehensive functions, flexible application, and open structure. Users can attach their own application modules, which have good versatility and maintainability. (2) Strong real-time performance and good parallel processing performance. MCGS is a true 32-bit system that makes full use of the multi-tasking technology of the 32-bit Windows operating platform. It has the function of time-sharing operation according to priority and performs time-sharing parallel processing of key tasks with strong real-time performance and non-key tasks with weak real-time performance in engineering operations in units of threads, making it possible for PCs to be widely used in engineering measurement and control fields. (3) Provides rich device drivers. By attaching device drivers to the system through ActiveDLL, it is possible to quickly develop beautiful and vivid engineering screens that integrate images, sound, and animation. (4) MCGS's powerful network capabilities can combine TCP/IP networks, 485422423 networks, and Modem networks to form large-scale monitoring and management systems. (5) MCGS's open expansion interface, based on OLE automation technology, allows users to quickly develop various device driver components, animation components, and various strategy components using VB. Through the OLE interface, users can easily customize their own specific systems. (6) MCGS configuration software fully utilizes database technology to store and process data, improving system reliability and operating efficiency. It also enables other application software systems to directly process the stored data. (7) MCGS provides a comprehensive security mechanism with a 4-level security and confidentiality mechanism. It sets different operating permissions for multiple users at different levels and also provides functions such as project passwords, locking software dongles, and project running time limits to protect the achievements of configuration developers. 3. Main Monitoring Parameters of Fluidized Incinerator The main monitoring parameters of the fluidized bed incinerator in this system include: water pump flow rate, wastewater volume, hot air temperature, packing tower inlet temperature, packing tower outlet water temperature, main combustion chamber outlet temperature, return material temperature, convection tube bundle mid-section temperature, furnace outlet temperature, economizer inlet temperature, economizer outlet temperature, air preheater outlet temperature, primary air pressure, secondary air pressure, furnace negative pressure, air preheater inlet air pressure, induced draft fan front negative pressure, packing tower inlet pressure, first material layer pressure in the stack, second material layer pressure in the stack, steam drum water level, furnace flame, induced draft fan speed, blower motor current, induced draft fan motor current, water pump motor current, burner motor current, ash discharge motor current, feed motor current, blower motor power, induced draft fan motor power, water pump motor power, burner motor power, ash discharge motor power, feed motor power, blower power consumption, induced draft fan power consumption, water pump motor power consumption, burner motor power consumption, ash discharge machine power consumption, and feed machine power consumption. The system has six frequency converters, which are used to control the blower, induced draft fan, water pump motor, burner motor, slag discharge motor, and feeding motor, respectively. The frequency converters communicate with the PLC via the PROFIBUS bus protocol. The program for CPU315-DP to obtain the power consumption of the induced draft fan motor is as follows: CALL SFC 15 LADDR := # W# 16# 10C RECORD:= P# DB5. DBX16.0 BYTE8 RET_VAL:= MW82 A BR = # temp0 A # temp0 ; JNB_001 CALL SFC 14 LADDR:= # W# 16# 10C RET_VAL:= MW 84 RECORD := P# DB5. DBX24.0 BYTE8_001:ABR = # temp1 A（ A # temp1 A（ LMW 84 L 0 = I ） JNB_002 L DB5.DBD 28 T # DB5.DBD52 SET SAVE CLR _002:ABR ） JNB_003 L0 T DB5.DBD 28 _003:NOP0 4. Hardware and Communication Siemens' programmable logic controllers (PLCs) have seen many improvements in functionality and usability, offering a superior performance-to-value ratio. They primarily include three products: S7-200, S7-300, and S7-400. S7 networks typically include: Multipoint Interface (MPI), Industrial Ethernet, PROFIBUS fieldbus, and TCP/IP protocol networks. The S7-300 PLC fluidized bed incinerator automatic control system utilizes a Multipoint Interface (MPI) network. This interface serves as both a programming interface and a data communication interface, using the S7 protocol. Data transmission between the PLC and the host computer is possible through this interface, forming an MPI network. Devices on the network are called nodes, and each node has a unique MPI address, set in the S7-300 hardware configuration. In the system, the S7-300 PLC is connected to the host computer via an RS485 to RS232 adapter (6ES7972-0CA23-0XA0). In the automatic control system of the fluidized bed incinerator, the host computer monitoring system uses a Lenovo commercial computer, a well-known domestic brand. Communication between the PLC and the host computer is achieved through the industrial control configuration software MCGS and the multi-point interface MPI network. In practice, software installation is required before using MCGS configuration software to communicate with the PLC. Locate "prodavedisk1setup.exe" and "prodave full version" in the support directory of the installation CD. If STEP7 is already installed, only "prodave full version" needs to be installed. After installation, use the program prodave-S7-miniPG-PC interface to set properties. Press the select button, select PCAdapter and add it to the right pane, then click the properties button and select programming devicePC is the only master. Since it is a PC-Adapter, a serial port COM1 or COM2 should be selected. Note that the baud rate setting should be consistent with the baud rate set in the actual PCAdapter used. If the above process is correct, the S7300 MPI driver can be used in MCGS. This driver is used for MCGS operation and reading/writing DB data blocks, inputs, outputs, and intermediate registers of Siemens S7-300 series PLC devices. If reading/writing DB blocks, the DB blocks must be downloaded to the PLC beforehand using programming software; otherwise, the communication status will be 1, indicating communication failure. 5. MCGS Industrial Control Configuration Software Configuration Process The user application system generated by the MCGS configuration software consists of five parts: the main control window, the device window, the user window, the real-time database, and the operation strategy. The main control window is the main framework of the project, responsible for scheduling and managing the user window; the device window is the working environment for connecting and driving external devices; the user window is mainly used to set the human-machine interface in the project; the real-time database is the data exchange and processing center for various parts of the project, connecting all parts of the MCGS project into an organic whole; the operation strategy mainly completes the control of the project's operation flow. The following points are key aspects of the configuration process: 5.1 System Menu and System Parameter Configuration In the MCGS "Main Control Window," the system menu and system parameters are defined and set according to the requirements of the fluidized bed incinerator automatic control system. The main control window of this system mainly includes: a parameter setting window with system parameter settings, manual operation, and display calibration parameter settings; system operation information including the monitoring main window and equipment operation information browsing; alarm information including real-time alarm information browsing and historical alarm information browsing; sampling data including pressure and flow sampling data browsing and temperature sampling data browsing; security management including password change, user login, login exit, and user management; and system exit options including exiting the system and shutting down the computer. 5.2 Implementation of Data Acquisition Function In the fluidized bed incinerator automatic control system, the PLC is responsible for real-time acquisition of data from the field and storing it in the PLC's internal registers; the MCGS configuration software directly accesses the PLC's registers through the host computer's serial communication port to achieve real-time data access from the field. Serial Port Parent Device Attribute Settings: The PLC device, as the lower-level machine, is a serial port device for MCGS. The COM port communication parameters set in this system have a baud rate of 9600, 8 data bits, 1 stop bit, and even parity. S7-300 PLC Attribute Settings: PLC rack number is 0; PLC slot number is 2; PLC station address is 2; its acquisition cycle is 1000ms for static measurement and 200ms for rapid measurement; when the initial working state is set to "Start", it enters the MCGS operating environment, and MCGS automatically starts operating the device. Internal Attribute Settings: Used to set the PLC's read/write channels to connect to the device channels, thereby sending data from the device to a specified data object in the real-time database, or sending the value of the data object to a specified channel output of the device. Data Processing: The data input from the PLC device is a value with physical meaning such as current and voltage within a specific range. It must be converted accordingly to obtain engineering data with practical significance. The MCGS configuration software's data processing function, in addition to engineering conversion calculations, can also perform data processing operations such as polynomials, reciprocals, filtering, function calls, and standard table lookup calculations, realizing powerful data processing functions. 5.3 MCGS Script Program The script program is a built-in programming language engine in the configuration software. When certain control and computational tasks are difficult to achieve through conventional configuration methods, the use of scripting languages ​​can enhance the flexibility of the entire system and solve problems that are difficult to address using conventional configuration methods. For example, part of the script program for running the policy in this system is as follows: CommState.AlmComment = CommState.Comment M10_1.Alm Comment = M10_1.Comment M10_2.Alm Comment = M10_2.Comment M10_3.Alm Comment = M10_3.Comment M10_4.Alm Comment = M10_4.Comment M10_5.Alm Comment = M10_5.Comment M10_6.Alm Comment = M10_6.Comment M10_7.Alm Comment = M10_7.Comment IF !len（!Get Current User()）>0 THEN UserWindow.frmMsg.lblUser.Text="User:"+!GetCurrentUser() ELSE UserWindow.frmMsg.lblUser.Text="User: Not logged in" ENDIF IF!Instr(1, strMsg.Value, "Device Name:") = 1 THEN strMsgExt.Value = "; Click to view device details." ENDIF IF CommState = 0 THEN SYSOFFLine = 0 ELSE SYSOFFLine = 1 ENDIF 6. Methods to Save I/O Points in Configuration Software Almost all industrial control configuration software is priced according to different input/output points, such as 32-point learning version, 64-point, 128-point, 256-point, 512-point, 1024-point and unlimited-point engineering version, etc., with significant price differences. Obviously, reducing the number of I/O points used in the configuration software can reduce the overall project cost and has great practical significance. The MCGS purchased for this system is 128-point, but the actual application requires more than 128 points. This is handled by a self-written program to meet the requirements. For example, when monitoring the operating status of each device in the main control window, the device can be numbered, and the number of I/O points in the configuration software can also be saved by using the internal functions of the MCGS system. The following is a program that displays the running status of a device by querying its device number. IF DevMode=3 THEN intComTmp.Value=!Val(!Mid(!I2Bin(AllOutDW), 6, 1)) IF IntComTmp.Value = 1 THEN DevState.Value="-Status: Running" ELSE DevState.Value="-Status: Stopped" ENDIF DevMsg0.Value="Running Frequency:"+!Str(DB1_DBW36)+"Hz" DevMsg1.Value="Flow Rate:"+!Str(DB2_DBW20)+"" ENDIF IF DevMode=8 THEN DevState.Value="-Status: Normal" DevMsg0.Value="Inlet Temperature:"+!Str(DB1_DBW04)+"℃" DevMsg1.Value="Outlet Temperature:"+!Str(DB1_DBW06)+"℃" DevMsg2.Value="Inlet Water Temperature:"+!Str(DB1_DBW08)+"℃" DevMsg3.Value="Outlet water temperature:"+!Str(DB1_DBW10)+"℃" DevMsg4.Value="Inlet pressure:"+!Str(DB2_DBW14)+"Pa" DevMsg5.Value="First bed pressure:"+!Str(DB2_DBW16)+"Pa" DevMsg6.Value="Second bed pressure:"+!Str(DB2_DBW18)+"Pa" ENDIF IF DevMode= 15 THEN DevState.Value="-Status:Normal" DevMsg0.Value="Temperature:"+!Str(DB1_DBW30)+"℃" IF!Val(!Mid(!I2Bin(AllOutDW),15,1))=1THEN DevMsg1.Value="Heater:Working" ELSE DevMsg1.Value="Heater:Stopped" ENDIF ENDIF User window.frmDevDetail.Caption = User window.frmDevDetail.lblDev.Text + DevState User window.frmDevDetail.lblMsg0.Text = DevMsg0 User window.frmDevDetail.lblMsg1.Text = DevMsg1 User window.frmDevDetail.lblMsg2.Text = DevMsg2 User window.frmDevDetail.lblMsg3.Text = DevMsg3 User window.frmDevDetail.lblMsg4.Text = DevMsg4 User window.frmDevDetail.lblMsg5.Text = DevMsg5 User window.frmDevDetail.lblMsg6.Text = DevMsg6 'IF!Instr(1, DevState.Value, "Stop") > 0 THEN frmDevDetail.cmdON.Visible = 1 'IF!Instr(1,DevState.Value,"Start")>0 THEN frmDevDetail.cmdOFF.Visible=1 7. Conclusion The MCGS industrial control configuration software has been successfully applied in the automatic control system of fluidized incinerator with its excellent characteristics. The software provides a complete solution for creating an efficient and practical computer monitoring system. We will build various data models on this basis for optimization design to improve combustion efficiency and stable control of furnace temperature and bed temperature, and further develop new types of ship incinerators. References [1] Yang Xianhui. Fieldbus technology and its application. Beijing: Tsinghua University Press, 1999. 110～132 [2] Beijing Kunlun Tongtai Automation Software Technology Co., Ltd. MCGS User Manual. 2003. [3] Beijing Kunlun Tongtai Automation Software Technology Co., Ltd. MCGS Reference Manual. 2003. [4] Shan Yajuan, Zheng Jianyong, Zhang Ruyao. Design of water plant automation system based on configuration software. Control Engineering, 2002, 9 (6): 35