Fully battery powered split-line smart water meter reading system

1 Introduction

The fully battery-powered split-line intelligent water meter reading system is suitable for use in environments where water meters are placed centrally outside households or where wiring is difficult between floors of high-rise residential buildings. The system uses a highly reliable double reed switch signaling base meter and is equipped with an intelligent digital water volume acquisition module that uses a dedicated integrated circuit instead of a single-chip microcomputer. It has high reading rate, low power consumption, and is fully battery-powered. As shown in Figure 1.

System composition schematic diagram

Figure 1 System composition diagram

Water meter: Built-in intelligent digital water volume acquisition module, used to detect water volume signal and water meter status information, and convert it into digital signal and send it to the concentrator.

Concentrator: Each concentrator can connect eight water meters, read the data and status information of each water meter, record and store the water volume of each water meter for the current month, cumulative water volume, tiered water price status and operation status; communicate with the meter reader interface.

Meter reader: The meter reader is used to read the water volume and water meter status data in each concentrator. Computer

: Configured with intelligent meter reading system management software, used to receive and summarize the data of each meter reader, and perform comprehensive processing on the meter reading data to ensure effective integration with the user company's information management system.

2 Detailed description of each part of the system

(1) Water meter: Uses a double reed switch to send the signal to the base meter.

(2) Function of the intelligent digital water volume acquisition module in the meter.

It uses a self-developed water meter dedicated integrated circuit, which does not require running software. It has the outstanding advantages of rich functions, strong anti-interference ability, high reliability, and low static and especially dynamic power consumption.

a. Collect the water volume signal sent by the double reed switch and store it in the module's dedicated integrated circuit chip; b. Built-in lithium manganese battery, the battery capacity is designed for ten years of operation, ensuring stable operation for eight years; c. Has the function of judging and recording line faults, water meter position changes and magnetic attacks; d. Has the function of judging and recording reed switch faults and low built-in battery voltage; e. Two-wire data communication function, the working status and water volume information of the water meter are sent to the concentrator through the two-wire communication interface. Even if the transmission line fails (short circuit or open circuit), the module will continue to work. The

communication interface can be plugged in and out with power on.

(3) Concentrator.

The concentrator is based on a single-chip microcomputer and consists of eight water meter interfaces, a clock circuit, an RS-232 (for connecting to a meter reader) communication interface and a power supply battery. The concentrator and the water meter use a timed detection method. The timer can be set manually from 1 hour to several days to read and record the water volume and working status information of each water meter. Its functional features are as follows:

a. Extract the accumulated water volume and working status data of each water meter acquisition module, store them in the serial E2PROM, and summarize them daily for future query; b. The communication interface between the concentrator and each water meter acquisition module has the functions of short circuit, open circuit monitoring and live plug-in and pull-out; c. Communication transmission interface with the meter reader: The concentrator is equipped with an RS-232 communication interface to connect with the meter reader, so that the management personnel can operate the concentrator and each acquisition module, read the water volume data in the module and the concentrator's work log, etc. The communication interface is designed to be pluggable under power; d. It is powered by a high-energy lithium manganese battery, and the battery capacity is designed to work for six years to ensure stable operation for four years.

(4) Meter reader function.

The meter reader can transmit water volume data, the working status of each water meter and control instructions between the concentrator and the PC. Its functions include:

· receiving and sending water volume data; · issuing control commands to change the working status of the water meter; · setting the operator code; · setting the house number address; · setting the step water volume; · setting the clock; · reading the meter box work log.

(5) Computer information management function.

The information management function of the system mainly includes the main functional modules such as receiving water volume data, setting the rated water volume, setting the house number, setting the system, and log query.

After reading the meter, the meter reader uploads the meter reading data to the information management system through the data cable. After comprehensive processing, it can be connected to the information management system of the water company to form corresponding query and statistical data, and carry forward at the end of the month. Managers and decision makers can obtain all data information through the computer management system of the water company.

The intelligent meter reading system can realize the supervision and management of meter reading work and ensure that the meter reader arrives at the household to read the meter on time. The intelligent meter reading communication technology provides a powerful tool for meter reading work and data management.

This system has good security and high reliability, provides data sharing, and ensures effective integration with the user company's information management system. The human-computer interface is friendly, simple and easy to learn, convenient and fast.

3 Meter box viewing function

In order to facilitate users to timely understand the cumulative water consumption, monthly water consumption and water meter operation status of their own water meters, a meter box can be installed in each unit or each building of the community. The meter box can be connected to up to 64 concentrators, and the meter reader is directly connected to the meter box to read the water volume data of each water meter, or communicate with the computer through a modem and the public telephone network. As shown in Figure 2.

The meter box is installed in the public part of the lower floor of each unit, and its functions are as follows:

Display function: Display the monthly water volume, cumulative water volume, module status and three-level tiered water price indication of users of different units, floors and door numbers in a circular display (the green, yellow and red LED indicators represent: par, bargain and special price respectively); Communication transmission interface: The meter box is equipped with an RS-232 interface, which can be connected to a handheld meter reader to read water volume data and meter box work logs, etc.

Power supply: The power supply in the meter box adopts a low-voltage switching power supply, which has the characteristics of high efficiency and strong anti-interference ability. The power supply can work normally within the range of 150VAC~280VAC. Power consumption: 4W~6W in normal operation.

Working principle diagram

Figure 2: Schematic diagram of working components.

4 Conclusion

This system has all the basic functions of the general "IC card water meter reading system", such as: pay first, then use water, automatic water cut-off for overdue payment, active payment by user using card, water sales management through microcomputer, no door-to-door meter reading and charging, payment reminder alarm function, closed battery power supply life of more than 5 years, battery low voltage power-off protection, etc. In addition, it also has the outstanding advantages of high reading rate, low power consumption, full battery power supply, long-term stable and reliable operation.