Item Type: Communication Module 1. Voltage: Measurement Range: AC 80-260V Resolution: 0.1 V Accuracy:0.5% 2. Current: Measurement Range:0-100A Resolution: 0.001 A Accuracy: 0.5% 3. Active Power Measurement Range:0-2.3 KW Min. Measuring Power: 0.4W Resolution: 0.1W 4. Power Factor Measurement Range: 0.00-1.00 Resolution: 0.01 Accuracy:1% 5. Frequency Range:45 Hz-65 Hz Resolution: 0.1 Hz Accuracy: 0.5% 6. Active Electrical Energy Metering Range:0-9999.99 kWh Resolution: 1Wh Accuracy: 0.5% Communication Protocol: 1. Physical layer protocol: Physical layer adopts UART to TTL communication interface Baud rate:9600,8 bit data bit,1 bit stop bit, no check 2. Application layer protocol The application layer supports for Modbus-RTU protocol for communication and currently only supports function codes such as 0x03 (read-hold register), 0x04 (read-input register), 0x06 (write single register), 0x41 (calibration), 0x42 (power zero). The 0x41 function code is limited to internal use (the address can only be 0xF8), used for factory calibration and back-to-factory maintenance, add a password of 16 bits after the function code, the password default is 0x3721. The address range of the slave computer is 0x01 ~ 0xF7, and the address 0x00 is used as the broadcast address. The slave computer does not need to reply to the host, and the address 0xF8 is used as the general address. The address can only be used in a single-slave environment and can be used for calibration and other operations. 3. Read the results of the measurement The command format for the host to read the result of the measurement is (8 bytes in total): Slave computer address + 0x04 + register address high byte + register address low byte + register number high byte + register number low byte + CRC check high byte + CRC check low byte. Reply of slave computer to the following command format is divided into two types: Correct reply: Slave computer address + 0x04 + bytes + registers 1 data high byte + registers 1 data low byte +...+ CRC check high byte + CRC check low byte. Wrong reply: Slave computer address + 0x84 + exception code + CRC check high byte + CRC check low byte. The exception code is read as follows (the same below): 0x01, illegal function; 0x02, illegal address; 0x03, illegal data; 0x04, slave error. The register layout of the measured results is shown in the following table: Register addressDescriptionResolution 0x000Voltage value measurement1LSB corresponds to 0.1V 0x001Current Measurement Value Low 16 Bits1LSB corresponds to 0.01A 0x0002Current Measurement Value High 16 Bits 0x0003Power Measurement Value Low 16 Bits1LSB corresponds to 0.1W 0x0004Power Measurement Value High 16 Bits 0x0005Energy Measurement Value Low 16 Bits1LSB corresponds to 1Wh 0x0006Energy Measurement Value High 16 Bits 0x0007Frequency Measurement Value1LSB corresponds to 0.1Hz 0x0008Power Factor Measurement Value1LSB corresponds to 0.01 0x0009Alarm State0xFFFF alarm0x0000 no alarm 4. Read and modify the slave parameters It supports reading and modifying the address and power alarm settings of the slave machine 5. Zero power 6. Calibration 7. CRC check