Abstract: This paper takes the ADμC812 microcontroller as an example to introduce a method for constructing a networked intelligent instrument using the PS2000 network interface chip. This networked intelligent instrument can be remotely controlled and managed via the Internet. Moreover, the system design is simple, requiring no familiarity with network protocols from the designer, reducing system hardware expenditure, lowering costs, and shortening the software and hardware development cycle. Keywords: Intelligent instrument, ADμC812 microcontroller, embedded microcontroller 1 Introduction Today, various embedded microcontrollers (MCUs) are widely used in intelligent instruments. Since MCUs are embedded in related devices without their own independent casing, these devices are called embedded systems. Embedded systems can provide certain services and control functions, and can acquire and utilize some information. However, how to connect these intelligent electronic products to the Internet so that people can remotely obtain information from these electronic products and control their operation has become a hot topic of concern in the information industry. With the rapid development of Internet technology, in the field of industrial automation, remote monitoring and manipulation of industrial processes and equipment operation status via the Internet has become possible. This paper takes the ADM812 microcontroller as an example to introduce a method for connecting a smart meter to the Internet using the PS2000 network interface chip. This method is simple, convenient, requires no familiarity with network protocols, is highly versatile, and has low development and application costs, making it highly practical. 2. Overall Scheme This paper proposes a design concept for a network-based smart meter. The smart meter uses a microcontroller as the main controller and the PS2000 network interface chip as an intermediate bridge. The connection between the smart meter and the Internet is achieved through the connection between the microcontroller and the PS2000, and the connection between the PS2000 and the network server. The PS2000 network interface chip internally integrates the MCUNet protocol, which is compatible with emGateway and OSGi protocols. Application system designers do not need to consider any network protocols; they only need to interpret and execute the instructions and data transmitted by the PS2000 to achieve Internet connection. The MCUNet network protocol is implemented by the PS2000. Similar to selecting a UART interface chip in a UART system design, choosing the PS2000 to connect electronic devices to the Internet saves MCU resources, simplifies the design, and lowers development costs. 3. PS2000 Structure and Principle Currently, many manufacturers both domestically and internationally are developing and promoting network chips. The PS2000 network interface chip, developed and proprietary by Wuhan Liyuan Electronics Co., Ltd., serves as a crucial "bridge" connecting intelligent measurement and control devices to the Internet, extending Internet technology to a wider range of automated measurement and control applications. The PS2000 is a microcontroller with on-chip network protocol interpreter and compiler modules, including MCUNet protocol compatible with eMGateway. This allows for the interface between the MCU application system and the PC-based eMGateway gateway. Additionally, it includes a DS2401 electronic tag interface and a serial interface. The electronic tag interface connects to the DS2401 integrated circuit, providing a unique identifier for each device in the network environment; the serial interface includes an SPI interface for connecting to the MCU, and communication interfaces for connecting to a PC via RS232, RS485, MODEM, RF, or IRDA. When the MCU application system exchanges information with the PC gateway, the PS2000 can handle network protocol interpretation and conversion, and control can be achieved through 17 simple instructions. Since the PC gateway provides HTTP service and can interface with a computer browser, the MCU application system can easily access the internet via the PS2000, enabling remote data acquisition, management, remote equipment control, online diagnostics, and services. Through the connection between the MCU and the network interface chip, intelligent instruments can be automatically connected to the Internet, forming networked intelligent instruments, thereby enabling remote monitoring and control of the industrial process site and equipment operation. 4. Connection Methods of Intelligent Instruments and the Internet Networked intelligent instruments are achieved through the connection between the MCU and the network interface chip. The following uses the ADMC812 microcontroller as an example to introduce its connection method. 4.1 Connection Method between ADmC812 Microcontroller and PS2000 The ADmC812 microcontroller is the latest product from Analog Devices (AD). It includes a high-performance 8-channel 12-bit ADC acquisition system, 2-channel 12-bit DAC, 80C52 MCU core, 8KB flash/Electrically Erasable Programmable Memory (EEPROM), 640 bytes of flash/EEPROM data memory, watchdog timer, power monitor, I2C-compatible SPI and standard UART serial I/O modules, and flexible power management solutions. Because the ADmC812 has sufficient on-chip resources, I/O ports, and peripheral devices, it can easily interface with a network. The PS2000 and the microcontroller exchange information through 17 simple control instructions and object-oriented concepts. The development steps are: ① Establish the objects to be controlled in the MCU system and determine the objects that need to be remotely monitored via the Internet; ② Establish the MCU system variable table; ③ Establish the MCU system status and performance table; ④ The MCU interprets and executes the commands transmitted from the network chip. In networked intelligent meters, it is generally necessary to establish objects such as A/D acquisition results and switch status control, and to create their respective variable tables and performance tables, which are then transmitted to the PS2000 during system initialization. Communication between the PS2000 and the microcontroller is initiated by the PS2000 through an interrupt request. The microcontroller first receives the incoming command and determines whether to exchange information or perform a corresponding operation based on the command. For example, approximately 10 seconds after system reset, the PS2000 sends an I_init command request to the microcontroller. Upon receiving this command, the microcontroller can set the PS2000's operating mode and perform initialization. 4.2 Connection Method between PS2000 and PC The connection between the PS2000 and PC is very flexible, allowing communication via RS232, RS485, or MODEM to meet remote, short-range, point-to-point, or point-to-multipoint communication requirements. The communication control word of the PS2000 communication control unit allows selection of RS232, RS485, or MODEM communication types. The PS2000 internally integrates the MCUNet protocol, which is compatible with emGateway and OSGi protocols. The MCUNet protocol is a communication protocol between MCU electronic devices and the Gateway on the computer platform. It has a simple structure and powerful functionality. First, the MCUNet protocol defines a master-slave relationship: the Gateway is always the calling system, and the electronic device is always the slave system. The Gateway can authorize the electronic device to call back. Second, it defines the electronic device's system status performance parameter table and variable table. Information exchange between the electronic device and the Gateway is based on the MCU system status performance parameter table and variable table. The electronic device's system status performance parameter table informs the Gateway of certain characteristic parameters of the electronic device's system, such as the number of variables in the system variable table and the number of bytes occupied by the variable table. The electronic device's system variable table lists the information that needs to be exchanged between the MCU and the Gateway, expressing it through a variable table. All information exchanged between the MCU and the Gateway is within the scope of this variable table; information outside the variable table will not be processed. 5. Conclusion This paper takes the ADμC812 microcontroller as an example to introduce a method for constructing a networked intelligent instrument using the PS2000 network interface chip. This networked intelligent instrument can be remotely controlled and managed via the Internet. Moreover, the system design is simple, requiring no familiarity with network protocols from the designer. It also reduces system hardware expenditure, resulting in low cost and shortening the software and hardware development cycle, demonstrating excellent application prospects.