Data acquisition and remote monitoring scheme of water supply network of water supply company

The dispatching and monitoring system of water supply network can monitor and control the remote field operation equipment, so as to realize the data transmission of pipeline pressure and water flow and the automatic control of valve switch, reduce the failure rate and improve the response time to the system. It is convenient to timely and quickly understand and control the remote pipeline and valve, reduce the failure rate and maintenance time, and reduce the number of water cuts. The data acquisition terminal of each water source monitoring point can automatically collect the real-time data of pipeline pressure and water flow and switch status, and the information is transmitted to the monitoring center of the water company. The monitoring center can find the fault location through the analysis of the transmitted data, so that when a remote fault occurs, it can solve the problem and restore the water supply in the shortest time.

System composition and configuration:

1、 System composition

The remote measurement, control and dispatching system of water supply network is composed of dispatching center, CDMA network APN special line, wireless CDMA network and remote terminal unit (RTU). The Remote Terminal Unit RTU is composed of each telemetry point scattered in the water supply network and each telemetry point of the branch plant. RTU series programmable CDMA RTU is used for remote data acquisition and transmission, on-site flow and switching value of pressure equipment Analog signals are connected. The remote terminal can collect and process data by itself, respond to the query request sent by each monitoring center through CDMA network, and send the data at real-time or historical time to the dispatching center.

Wireless CDMA network: access the network in the form of dedicated IP address of China Telecom CDMA network. Each SIM card is bound with a fixed internal IP and has an independent Internet access APN name. A dedicated APN name is allocated in the network. Ordinary users are not allowed to apply for this APN. The SIM card used for CDMA private network only opens this private APN, and the use of other APNs is restricted, and the use of private APNs by SIM cards outside the network is also restricted.

CDMA network APN dedicated line: through the optical fiber dedicated line with Mobile Communication Co., Ltd., the DTU module in the wireless CDMA network can directly access the host in the water supply company. The use of APN special line communication is stable, and there will be no frequent disconnection and false online during dialing; The communication bandwidth is large, which allows multiple DTU data to be collected at the same time; Faster communication and save acquisition time.

Dispatching center: the dual computer backup system is composed of two sets of PC equipped with upper computer monitoring system, CDMA optical fiber dedicated line and CDMA module dialing. Usually, the main system works. When the main system fails, the standby system is used. The main and standby system is set in the company's Dispatching Center and connected with the company's intranet through the network. The PC of the dispatching center drives the CDMA communication module to send configuration information and control information to RTU, And receive the data and alarm information reported by the lower computer, conduct regular patrol test, manual patrol test, random sampling test and group patrol test data, and manage the collected data at the same time, with the functions of query, statistics, report and so on. And print the data at any time for query. The system software consists of two parts: monitoring system software (workstation software) and front-end computer software.

The monitoring system software is secondary developed by using configuration software. The software has intuitive picture and friendly interface. It has many functions, such as data display, simulation animation, data query, alarm display, curve report generation and so on.

2、 The specific functions of the system are as follows:

Send configuration information and control command to RTU;

The data sent by RTU automatically enters the database, and the database has certain security measures;

Handle the alarm information of RTU;

Data telemetry function: regular patrol test, manual patrol test, random sampling test and group call test;

Remote control function: control the on / off state and remote signaling switch state of RTU switching value output point;

Parameter status management function: set and modify the upper and lower limits, measuring range and communication parameters of each measurement data (including the setting of station number, IP address and other parameters at RTU end);

Online configuration function: adding RTU data acquisition points and other parameters can be completed through configuration definition;

Database management function: build a database for the measured data, process the data, query the historical data and print the report;

It has data display function: it can display various measured data, remote signaling switch status, various system graphics, etc.

Data sharing function: run the configuration software and web service software on the host, so that the workstation of the broadband intranet of the water supply company can log in and view the real-time data of all monitoring points and the historical data stored in any time period only through the web browser. Control the data of those monitoring points that the user can access through user identity authentication and authorization. 

system configuration

1、 Flow and pressure data acquisition

1. Plug in ultrasonic flowmeter is used for flow data acquisition;

The plug-in ultrasonic flowmeter uses the principle of low voltage and multi pulse receiving and transmitting, and adopts the patented technology of double balanced signal differential transmitting and receiving and hardware independent design; The plug-in sensor solves the problem that the external clamp sensor can not receive the signal due to long-time signal attenuation and scaling on the inner surface of the pipeline

Accuracy 1.0%

Repeatability 0.2%

Velocity range: 0-64m / S

Measurement cycle 500ms (2 times per second, 128 groups of data are collected in each cycle)

Measurement principle, ultrasonic time difference principle, 4-byte IEEE754 floating point operation

Communication protocols: Modbus protocol, MBus protocol and Fuji extension protocol. MODBUS-RTU protocol or modbus-ascii protocol is recommended

Other functions automatically memorize the accumulated flow and working status of the previous 512 days, the previous 128 months and the previous 10 years; Automatically memorize the first 30 times of power on and power off time and flow, and can realize automatic or manual supplement;

Programmable quantitative controller (can be started with external input signal or MODBUS command);

One bidirectional serial interface can connect multiple external devices such as 4 ~ 20mA, data recorder and so on;

The working parameters can be solidified into the flash memory in the machine and automatically called out when powered on;

Users can realize the software upgrade fault self diagnosis function through the code file transmitted by e-mail.

Failure time timer.

Working current 50mA (without keyboard display and buzzer)

CR2032 is used as the backup battery, and the data will not be lost for 100000 hours under the condition of 24VDC power failure

Ambient temperature - 40 ℃ ~ 85 ℃ (if it is greater than this temperature range, please contact Juying soaring)

Continuous working hours

Power supply 24VDC (battery powered: service life 1 year)

Standard L1 type, applicable pipe diameter DN300 ~ 6000mm

Protection grade IP68 (water immersion)

The inner diameter is 200mm ~ 6000mm (the inner diameter of π type pipe section can be as small as 2mm)

The length of straight pipe section is ≥ 10d upstream, ≥ 5D downstream, and ≥ 30d from the pump outlet.

Measuring medium types: water, seawater, acid-base liquid, food oil, steam, coal, diesel oil, crude oil, alcohol, beer and other uniform liquids in full tubes that can transmit ultrasonic waves. Turbidity: ≤ 20000 ppm, sewage measurement effect is good, and most sewage pipelines can be measured stably.

Temperature: - 40 ℃ ~ 160 ℃

Flow direction: the forward and reverse flow can be measured respectively, and the net flow can be measured.

2、 CDMA RTU data acquisition and transmission module

Basic functions:

Standard RS232 / 485 interface is used for data acquisition and remote transmission of pressure, flow, temperature and other sensors

Provide 8 channels of 4-20mA analog signal input with differential 24bit accuracy

Four optical isolation I / O input interfaces are provided, of which the first two channels can be connected to pulse signals

Provide 2-way passive contact output, with contact capacity of 5A / 220V, and the default state is optional

Built in 1m flash memory, data is automatically stored, and the data can be completely saved even if the network is abnormal

Built in industrial clock, which can report data at fixed time and fixed point

The analog quantity acquisition part automatically converts the range and can set the upper and lower limit alarm values

The equipment is automatically connected to the network when powered on, and automatically reconnected after disconnection

Support the networking mode of fixed IP, domain name resolution and private APN

The data reporting format is Modbus protocol

The device automatically logs in to the network and automatically reconnects after disconnection. Users are free of maintenance

Support special setting software and remote SMS parameter setting function

Support remote software upgrade

The communication protocol is perfect, the configuration software (Asian control, Zijinqiao) supports, and the user is free of development

Wide voltage range power supply: dc5v-30v (battery power supply: service life of 1 year)

Standard terminal blocks and notched mounting holes are convenient for equipment installation

The working status indicator of the equipment is convenient for equipment maintenance

Enhancements

A variety of communication protocols are embedded to unify the data reporting format and reduce the difficulty of host computer development

When the communication interface is RS485, one device can copy multiple instrument data, up to 6 kinds

8 analog channels can access voltage signals

It supports the function of connecting multiple centers, and can connect up to 4 centers

Support SMS reporting mode, and actively extract data through SMS.