Large-caliber IC card remote water meter

The large-diameter IC card remote transmission water meter adopts the dual CPU mode. The electronic module is divided into two parts: the meter head and the controller. The meter head part is installed in the downhole to complete the water metering, data storage and valve control, and the controller part completes the card. Read and write operations, display and logic judgment functions. Both parts use RS-485 for data exchange and connection.

The controller part of the IC card selects the CPU smart card, and the card protocol is designed according to the Tongzhou water meter CPU card data protocol. The ESAM security module is installed in the controller to complete the key security authentication of the CPU card and the water meter controller to ensure data security. After the data processing is completed, the corresponding data is displayed on the display module, and the contents of the display request are the same as before. The header part of the CPU to complete the measurement data collection and storage work, and according to the logical calculation results to determine the opening and closing of the valve. When the user inserts the water-purchasing card into the control, the controller first performs key security authentication. After the certification is completed, the water-purchasing amount data is read into the ESAM module for storage, and at the same time the RS-485 interface is started to transfer the water-purchasing amount data to the meter head. After receiving the purchase volume data, the header appends it to the remaining amount of water, and returns the new remaining amount of water and accumulated water consumption data to the controller. After the controller receives the return data, it will write the relevant data back to the water purchase card, and display the relevant data cyclically. After the display is completed, the delay will be extinguished.

Edit the head of this paragraph Under normal circumstances, each correct measurement of a valid pulse, the remaining amount of water minus 1, when the remaining amount of water is 0, automatically close the valve to cut off the user's water. At this time, the user can initiate data exchange between the controller and the header through the card, read out the header data to the controller and display it through the card or reading and writing device. A 3.6V Li-ion battery is installed on the meter header and controller respectively to supply power to the respective electronic modules. The battery detection circuit is also set to detect the battery capacity. When the battery capacity of the meter head is insufficient, the valve will be closed automatically. When the controller part of the battery capacity is insufficient, the controller will also issue a valve closing command to close the valve. At this time, the user can insert a card for checking. After the card is inserted, the controller first issues a meter reading instruction, copies the header data and working status back to the controller, and displays the data and status of the controller in combination.

The connection between the head of this paragraph and the controller is completely dependent on RS-485 for transmission. It adopts 4-wire system, two power lines, and two data lines. The power of the 485 communication is provided by the controller and does not use the header power supply. In order to minimize power consumption, the controller and the header usually do not perform data communication. The controller controls the data communication at the end of each month and the header to transfer the header data and status to the controller. Other times, the communication is initiated after the IC card is inserted. When the user does not insert the card, no communication connection is made. If there is no battery voltage in the header part, I shall send data to the controller (after closing the valve). When the remaining water in the water meter exceeds the limited purchase amount, the meter controller is prohibited to add the amount of water purchased in the water purchase card to the meter. Go, the prompt code "E-17" is displayed.