Abstract : This paper introduces a novel remote meter reading system. This system collects electricity data using a PLC and transmits it over long distances via the PLC and the public telephone network. It features a simple structure, accurate metering, and ease of operation, and has broad application prospects. Currently, remote meter reading and control systems for electricity meters are receiving increasing attention from power sectors. Using a modem combined with a computer and utilizing the public telephone network for remote control not only facilitates the transmission of control information but also allows for highly complex and rich control information. However, such systems are costly and structurally complex. This design uses a PLC to collect and control the electricity consumption of the power supply system, connecting it to a host computer via the public telephone network. The entire system offers flexible control, reliable operation, and low cost, making it a promising candidate for widespread application. This design employs a timed electricity consumption collection method, collecting and recording data in time periods according to user requirements. A pulse meter converts the electricity signal into a pulse signal, ensuring a proportional relationship for convenient electricity measurement. Assuming data is collected in 7 time periods each day, each channel needs to record 16 characters per day: 1 character for the year and month, 1 character for the day and month, and 14 characters for the hour and minute (7 groups total). These data are stored in the DM (Data Center). If each cycle is recorded as one month, approximately 500 words of memory (16 x 31) are required. The data stored in the DM is periodically read by the host computer. The key to this system is storing a large amount of data and having communication capabilities. For the PLC, only a few input points are needed, no output points are required, but a system clock is necessary. The CQM1 series PLC has a communication port and a large DM area, which can be configured with a memory unit with a system clock. The specific configuration in this design is as follows: Arbitrary remote metering of electricity can be achieved through a modem and public telephone network. This system adopts a timed acquisition method, recording the actual electricity value according to time periods and storing it in the DM data area. The specific process is as follows: Set A17 as a real-time clock, representing hours and minutes, compare it with 1000, and determine if it is 10:00. If it is, the equality flag is ON, and the content of the channel to be acquired is stored in the DM area. After storage, the pointer is incremented by 1, and then it is checked whether the pointer exceeds the data area range. If the count is within the limit, nothing is done; if it exceeds the limit, 0000 is reassigned to the pointer, causing it to start storing the data again from the beginning of the storage area and begin the next cycle. In this design, to ensure the accuracy of power acquisition and prevent pulse loss, a timed acquisition subroutine is executed continuously, acquiring data every 10ms. Due to the timed acquisition method, the data format is fixed, and the length of the storage area is coordinated with the length of the stored data. Time does not need to be stored while storing the data. Because the pointer value indicates the current data position, and different data positions represent different times, the regularity is obvious, making it easy to determine the storage time of the data. To save investment and improve control efficiency, remote control can be adopted. The CQM1 machine can be easily remotely controlled with appropriate configuration without increasing the total number of controllable I/O points. Connecting to input or output terminals via the interface unit, the maximum distance can reach 500m; this scheme is called "terminal connection." The maximum transmission distance of this control method is 500m, but the actual distance depends on the transmission delay and power wiring method. The CQM1 main unit connects to a B7A interface unit, while the corresponding terminal is connected remotely. The terminal and interface are connected via twisted-pair cable. The interface unit's structure is similar to the CQM1's I/O module and can be connected to the CQM1 main system using the same method. Interface units are divided into input and output terminals; terminals are further divided into input and output categories. Using this method, one PLC can connect to 64-96 electricity meters. Besides using a host computer for monitoring and recording, a seven-segment decoder can conveniently monitor electricity usage. In this design, the electricity data is directly output from the output unit to the seven-segment decoder, which then displays the collected electricity value. Each digit occupies four points. Using an OMRON dynamic output unit (one unit can output 128 points), and with external hardware decoding configured with latching, one unit can stably display a 32-bit digit. In this design, the PLC system uses pulse counting instead of analog units, greatly improving the system's anti-interference capability. In addition, during data acquisition, the content of A17 can be stored in the DM word pointed to by the modified pointer, then modified, and the control pointer can be judged again. Not only A17, but sometimes the year, month, day, and some flags can also be pre-stored, using the same method as the data storage method. Simulation studies and practical applications have proven that this system operates reliably and provides accurate electricity billing.