A new grain sorting line was installed at a port, and F600 intelligent weighing instruments with RS-485 interfaces were selected. The sorting line has 32 scales and 16 hoppers. The F600s control the weighing, unloading, and sorting operations via a PLC. The F600s communicate with an industrial control computer to perform tasks such as counting and summarizing the number and weight of bags sorted to the correct or incorrect weight, and printing daily and monthly reports. Each hopper has two weighing hoppers, and each hopper is connected to one F600 intelligent weighing instrument. The two F600s (scale A and scale B) are connected to one PLC (FX2N-80MR) via their respective process input/output connectors. The start/stop buttons control the start/stop of scales A and B via the PLC. The F600s operate in sequence mode. During normal operation, the F600 controls the large, medium, and small input of grain through the PLC based on three set values ​​SP1, SP2, and SP3. According to the set time and mode, after comparison, stabilization, and judgment, it outputs signals such as completion, positive quantity, excessive quantity, and insufficient quantity. The PLC makes judgments, processes, indicates, or alarms to notify the operator to take necessary actions. When a bag clamping signal is received, it determines whether scale A or scale B starts discharging. After discharging, it starts the next cycle. Features of F600: (1) Color touch screen display with multi-level menu-style mode tree settings. (2) Diverse display. Digital, trend graph, and indicator light displays. (3) Convenient standard calibration. Two methods are available: equal quantity input calibration and weight calibration. (4) Accurate measurement and control. Automatic drop compensation in unloading mode effectively compensates for the drop error caused by weighing. (5) Multiple weighing modes are available. There are feeding, unloading, and sequence modes. (6) Rich control functions. Weighing switch control can be achieved through input/output connectors, and PID continuous control can be achieved through D/A digital-to-analog converter optional accessories. (7) Multiple optional expansion functions. BCD data output, RS-232C communication interface, RS-485 communication interface, D/A converter and CC-Link, DeviceNet communication and other functions are available. (8) Power-on self-test function. Self-test of digital signal processing, memory, touch keys, external input/output, etc., and error prompts. II. Driver Development MCGS is a set of configuration software for quickly constructing and generating computer monitoring systems. Its features are: simple and flexible visual and modular operation interface, clear blocks, easy to learn and use. The user application system consists of five parts: main control window, device window, user window, real-time database and operation strategy; it has good maintainability and expandability. The three basic types of components (device component, animation component, strategy component) complete all the work of the three major parts of MCGS (device drive, animation display and process control); it has reliable, safe, animation display, report, alarm, trend, printing, network and other functions. This software was selected for a grain sorting project at a port. This project requires a monitoring computer to communicate with an F600 weighing instrument to collect and record weighing data. Based on the characteristics of the monitoring computer, MCGS configuration software, and the F600 instrument, RS-232/RS-485 communication with the monitoring computer is used. This method requires an F600 RS485 driver (i.e., a communication sub-device driver that calls the serial port device, executes the RS-485 communication protocol, and reads data from the F600 weighing instrument). However, MCGS currently does not have this driver, so it needs to be developed independently. The RS-485 half-duplex serial communication standard is simple and easy to network, highly scalable, and can connect multiple weighing instruments in parallel, thus meeting many monitoring function requirements. It has strong anti-interference capabilities, is easy to install, and has a certain degree of applicability. The F600 weighing instrument requires 8 data bits, 1 stop bit, no parity, a CR terminator, an ON terminating resistor, and a two-wire system. Communication format: ID0001RACR, ID0001RA+100.00CR. The development steps for the F600RS485 driver are as follows: (1) Set the configuration environment to call the attributes and methods. The device type is a sub-device, the device category is a serial communication sub-device, the number of channels is 3, the device component type name is "My Device f600", initialize the initial value of the device, and write the data type and comment program for each channel of the device component. (2) Run the program called by the environment. The program flowchart is shown in Figure 1. [align=center] Program flowchart[/align] First, collect the completion signal. If the completion signal is collected, then collect the weighing data value. Otherwise, collect the completion signal of the next F600. The program written in VB6.0 is omitted. (3) Testing and Connecting the F600 Device Driver Components: Start the MCGS configuration environment, open the MCGS project, run the project group in the VB environment, test the configuration environment interface and the runtime environment interface. After successful debugging, recompile the project to generate a dynamic link library file, and copy it to the D:\MCGS\Program\Driver directory (the installation directory of MCGS is D:\MCGS). The F600 RS485 driver program is now successfully developed. III. Hardware and Communication: The monitoring computer hardware uses an Advantech industrial PC IPC610 and an Advantech ADAM4520 converter. Each F600 is connected to a set of weighing sensors. Every two F600s are connected to one PLC, which controls the actions of the F600s and related valves and material gates. The material level switch on the silo is controlled by the PLC for dispensing, and simultaneously transmitted to the industrial PC via the Advantech ADAM4053 digital input module to display the material level. The weighing instrument uses serial communication, with 8 data bits, 1 stop bit, and no parity bit. RS-485 shielded twisted-pair communication cable is used on site to improve anti-interference and load-bearing capacity and increase communication distance. RS-232/RS-485 active opto-isolated converter is used at the serial port of the industrial control computer to further enhance anti-interference capability. The hardware system is shown in Figure 2. [align=center] Hardware system diagram[/align] Four configurations Create a new project in the configuration environment, configure relevant parameters and screens, and generate the user system database. (1) System menu and system parameter configuration. Open the main control window and define and set the system menu and system parameters. (2) Equipment component configuration. Set and configure relevant parameters of F600 weighing instrument in the equipment window: 4-bit address, 8-bit data bits, 1-bit stop bit, no parity, end symbol CR, terminal resistor ON, two-wire system. (3) User interface configuration. According to the characteristics of the process flow, use MCGS tool to design and configure the main control interface in the user window. Such as configuring real-time data reports, historical data reports, real-time curves, historical curves, printing, security mechanisms, etc. Based on the completed signal read, determine whether the current value is repeated with the previous completed signal. If it is repeated, discard the current value. If it is not repeated, determine whether the read weight value is out of tolerance. If it is out of tolerance, add one to the number of bags with out-of-tolerance and add the weight with out-of-tolerance to the current weight value. If it is not out of tolerance, add one to the number of bags with positive weight and add the weight with the current weight value. Select the grain type, and store the number of bags and weight into different variables according to the grain type. According to the time or shift, classify and summarize the positive and out-of-tolerance bag counts and weights of different grain types. Perform historical data processing and make different function print buttons to realize the printing functions of daily reports, monthly reports, etc. (4) Real-time data object configuration. Open the real-time database window and define and set the relevant data attributes. (5) Run strategy configuration. In the run strategy window, set the startup strategy, loop strategy, save strategy and alarm strategy respectively. Test the equipment communication in the development environment to understand the equipment and its communication status, and find the cause easily. V. Conclusion Through the implementation of this project, we have gained a deeper understanding of MCGS5.5. Having mastered the configuration and device driver development methods of MCGS, the development of MCGS device drivers has been enriched and has a certain degree of applicability. The successful development of the F600RS485 driver has laid the foundation for its widespread application. Currently, this driver is planned for application in other grain sorting projects at a port.