Abstract: This paper demonstrates the cost-effectiveness advantage of Delta Automation products in automated system integration solutions by integrating Delta Automation products into an automatic balance measurement control system. Keywords: PLC, Human-Machine Interface, Servo System 1 Introduction Balances are widely used in scientific research, national defense, finance, building materials, metrology, highways, mining, and other enterprises for metrological testing. As an important weighing instrument, balances come in many types, broadly categorized by application as industrial balances, analytical balances, and special-purpose balances. Structurally, they can be classified as equal-arm double-disc damped balances, mechanically weighted balances, semi-automatic mechanically weighted electro-optical balances, fully automatic mechanically weighted electro-optical balances, single-arm balances, and electronic balances. Precision-wise, they can be divided into precision balances and ordinary balances. While the structures of various balances differ, their basic principles are the same, all based on the lever principle. A balance is a specialized metrological device; depending on the measuring range and the object being measured, the main frame and mechanical structure of the balance vary, as do the weight systems. The core mechanical components of the balance system determine its metrological accuracy. This article introduces an automatic metering balance, a non-standard balance metering device specifically used for measuring gas quality. It measures whether various gas indicators of aircraft engines meet the requirements and provides reference data for engine R&D personnel to improve engine performance. It has positive significance for the R&D and performance improvement of core components of Chinese aircraft. 2 System Design 2.1 System Analysis The weight addition and subtraction systems of balance equipment developed by domestic professional manufacturing industrial balance research institutions are all manual or mechanical weight addition and subtraction, which lacks flexibility in operation and the measurement efficiency and quality are not conducive to improving the economic value of equipment and product grade. The successful development of the automatic metering system of this project fills the gap in the automation control of domestic balance metering equipment. The equipment has completely independent intellectual property rights. The control system uses Delta PLC as the main controller and drives a 4-axis independent AC servo system. The host computer human-machine interface monitors the balance operation status and inputs the weight addition quality. The system realizes accurate automatic weight addition and subtraction. Whether in terms of core components or control system, it can be compared with similar foreign equipment. 2.2 Composition Structure of Automatic Metering System (1) Balance Switch: A 4 kW three-phase asynchronous motor is used, and the stop position is controlled by a proximity switch. (2) Weighing pan lifting: A 2.2 kW three-phase asynchronous motor is used, and the stop position is controlled by a proximity switch. (3) Automatic weight addition: There is one set on each of the left and right pans, divided into kilogram group (400W servo motor driven); ten kilogram group (400W servo motor driven); and one hundred kilogram group (120W asynchronous motor driven). The three sets of weights should be able to achieve automatic combination of any mass from 0 kg to 199 kg. 2.3 System design (1) Control system principle: The automatic weighing control system of the balance adopts a dual master station control mode. The human-machine interface and the industrial control PC are used as master stations to monitor the actions of the slave PLC. The HMI is connected to the PLC COM1 (RS232) communication port through the COM1 communication port, and the industrial control PC is connected to the PLC COM2 (RS485) communication port through the COM1 communication port, thereby realizing the monitoring functions such as command issuance and action feedback, and realizing the requirements of equipment automation control. The main controller, Delta PLC, is connected to four independent servo drive systems. High-speed pulse control of the servo travel distance and speed achieves precise weight addition and subtraction control requirements. At the same time, the PLC analog acquisition module collects pressure sensor signals in real time and converts them into pressure values ​​for display and program processing by the host computer. The detection of action conditions and the completion of action drive of other components of the balance are all achieved by the PLC digital input/output interface according to the program logic output, as shown in Figure 1. Figure 1 System principle block diagram (2) Configuration design: The configuration of the control system technical solution is shown in Table 1. Table 1 only lists the main components of the control system. In addition, it also includes low-voltage electrical appliances (low-voltage circuit breakers, electromagnetic contactors, electromagnetic relays, buttons, indicator lights, etc.), detection sensors (pressure sensors, proximity switches, limit switches, etc.), analog signal transmitters, etc., which will not be described in detail here. Table 1 System Configuration Design (3) Delta DVP28SV11T PLC Function Description: The DVP28SV11T provides parallel high-speed expansion interfaces, which can expand various network interfaces such as Ethernet, DeviceNet, ProfiBus, and analog and temperature modules to meet real-time control requirements. Up to 16 modules can be expanded (8 on the left and 8 on the right), including special expansion modules such as analog, temperature, axis control, and communication. The DVP28SV11T host has built-in 200KHz four-axis independent motion control commands and two sets of linear/circular interpolation functions, making position control applications flexible and convenient. The DVP28SV11T PLC is used in 4-axis servo positioning control; cutting machines (high-speed servo control); XY servo robotic arms; servo control for material gripping applications; and industrial equipment applications in optoelectronics, semiconductors, textiles, energy saving, and building automation. Delta DVP28SV11T PLC Product Specifications: Main Unit Points: 28; Maximum I/O Points: 512; User Program Capacity: 16K Steps; Instruction Execution Speed: 0.24μS (Basic Instruction); Communication Interface: Built-in RS232, RS485, compatible with MODBUS ASCII/RTU communication protocols; Data Memory: 10,000 Words; File Memory: 10,000 Words; High-Speed ​​Pulse Output: Supports 4-point (Y0, Y2, Y4, Y6) high-speed pulse output, 2 groups (Y0, Y1) (Y2, Y3) AB phase pulse signal outputs, and 2 groups (Y0-Y3 & Y4-Y7) dual-axis interpolation functions, all up to 200KHz, with 4 built-in hardware high-speed counters. 2.4 Control System Electrical Design: The PLC main controller control circuit wiring is shown in Figure 2. It should be noted that the servo motor can accurately find the different angles corresponding to the different kilograms mentioned above. The servo motor drives the reducer to drive the mechanical cam system on the rotating shaft to realize the automatic weight-adding action. For the electrical control system, as long as it can accurately find the preset angle, it can meet the requirements. Figure 2 PLC circuit diagram 2.5 The automatic operation of the balance metering automation process system after power-on is as follows: Detect whether the balance is closed. If it is in the closed position (SQ2+), there is no action. If it is not in the closed position (SQ2-), the balance is closed (KM2+); Detect whether the pan is in the lowered position and the can is in the retracted position: If the pan is in the lowered position (SQ4+, SQ6+) and the can is in the retracted position (SQ19+, SQ21+), there is no action. If the pan is not in the lowered position (SQ4- or SQ6-) or the can is not in the retracted position (SQ19- or SQ21-), the pan is raised. (KM3+, KM5+), retract the cans (SB2+, SB4+), lower the pans (KM4+, KM6+); the weight-adding system returns to zero; a message indicates the balance system is normal and manual control is permitted; the balance opens (KM1+) [Prerequisite: left and right cans are in the retracted position (SQ19+, SQ21+), left and right pans are in the lowered position (SQ4+, SQ6+)]; the balance closes (KM2+); the balance switch stops; [An additional function button on the touchscreen allows stopping the balance at any position during the opening and closing process]; the left pan rises (KM3+). [Prerequisite: Balance is closed (SQ2+)]; Left pan descends (KM4+) [Prerequisite: Balance is closed (SQ2+)]; Left pan advances (SB1+) [Prerequisite: Balance is closed (SQ2+), Left pan rises (SQ3+)]; Touchscreen buttons and external buttons are available simultaneously; Left pan retreats (SB2+) [Prerequisite: Balance is closed (SQ2+), Left pan rises (SQ3+)]; Touchscreen buttons and external buttons are available simultaneously; Right pan rises (KM5+) [Prerequisite: Balance is closed (SQ2+)]; Right pan descends (KM4+) [KM5+] M6+) [Prerequisite: Balance is in the closed position (SQ2+)]; Right tank advance (SB3+) [Prerequisite: Balance is in the closed position (SQ2+), right pan is in the raised position (SQ5+)]; Touchscreen buttons and external buttons are available simultaneously; Right tank retreat (SB4+) [Prerequisite: Balance is in the closed position (SQ2+), right pan is in the raised position (SQ5+)]; Touchscreen buttons and external buttons are available simultaneously; Add weight according to given value [Prerequisite: Balance is in the closed position (SQ2+)]; System emergency stop: All actions in the system stop [including all manual and automatic actions]. Touchscreen buttons and external buttons are available simultaneously. 3. Main controller program design The difficulty and complexity of the PLC control program lies in the arbitrary combination of weights from 0 to 199Kg, and also in considering that after the weight value changes, the servo needs to find the origin and then run to the preset angle. There is one set for each of the left and right weight addition systems, so the program size is very large. The PLC core control program is shown in Figures 3 and 4 respectively. Figure 3. Trapezoidal diagram of left-side loading origin regression Figure 4. Trapezoidal diagram of left-side servo loading 4. Conclusion Providing customers with cost-effective and perfectly integrated solutions is Delta Electronics' marketing strategy. Providing stable and reliable system integration solutions is the guarantee of serving customers. This automatic balance metering system project combines Delta's HMI, PLC, servo drive and other automation products to develop a stable and reliable system for customers. It not only meets the customer's gas weighing and detection process requirements, but also improves the technological content and work efficiency of the automatic balance metering system. It has been highly recognized by customers and users. Customers said that similar automatic balance metering systems will adopt this mature technical solution in the future, which once again proves that Delta Electronics is a trustworthy partner for customers. References [1] Delta DVP-PLC Application Technology Manual Program Section [2] Delta DVP-PLC Application Technology Manual Special Module Section [3] Delta DOP Series HMI Application Technology Manual [4] Delta ASD-A Series AC Servo Drive User Manual