Ultra low power rain gauge RTU scheme

System overview

Battery powered GPRS / CDMA wireless rain gauge is a high-performance measurement and control device developed for market demand, which integrates signal acquisition, process IO control and wireless data communication. It adopts ultra-low power consumption technology and uses disposable lithium battery for power supply. It can directly collect standard transmitter signals or analog signals output by instruments, level signals, dry contacts, pulse signals, etc. in real time without power supply on site, The wireless upper and lower limit detection is the best means to implement the wireless alarm process.

Scope of application

Remote monitoring of water source well

Remote monitoring of Hydrology (rainfall and water level)

Remote measurement and control system of river water level valve

Groundwater level monitoring

Hydrological and rainfall monitoring

Hydrological and rain monitoring

Geological monitoring, etc

system function

Realize the signal acquisition and counting function of 2-way tipping bucket rain gauge

Realize the signal accumulation function of tipping bucket rain gauge

Be able to identify rainy season and non rainy season

Realize the regular data return to the server, which can be divided into rainy season and non rainy season

When the server connection fails, the method of sending back short messages is adopted to send back the fault and collect data

The server can remotely configure the return time in rainy season and non rainy season

Server configurable time

Hardware support

Rtu4100-l

1) Product introduction

Product features

Power supply mode of 3.7V lithium battery

Provide RS232 and RS485 communication interfaces

Ultra low power consumption, standby current as low as 25-35 µ a, suitable for long-term work in the field

Various standby working modes can be customized

Support server configuration time

Support Modbus ASII and RTU protocols

Support custom handshake package and heartbeat package

Have a unique ID number

Only Automatic wake-up mode is adopted, and 3ua-4ua can be achieved in standby mode.

Collect the information of 4 sensors regularly and store it in flash

Connect with the server regularly and upload the collected data

2) Relevant information

General dtu4100 instructions

Low power configuration software

DTU configuration software

Ultra low power GPRS specification

3) Workflow

Normal standby

When the timing acquisition time is up, wake up the equipment, collect data, store the collected data and stand by.

When the scheduled return time is up, wake up the device, online server, upload data and standby.

It supports four standby modes: week, hour, minute and interval

[interval time] can be configured as 0-65535 second interval.

[time of day] can be configured to wake up from 1-7 minutes in a week.

[hour] mode can be accurate to the minute of every day, and can be configured as 1-7 time points to realize fixed-point wake-up.

[minute] mode can be accurate to the minute time in each hour, and can be configured as 1-7 time points to realize fixed-point wake-up.

4) Power consumption calculation

Rtu-l series is mainly divided into three working modes

Timing mode, alarm mode and networking mode

Working mode power consumption

Timing mode (3-4) UA can only wake up regularly

Alarm mode (20-33) UA can externally trigger wake-up

Networking mode 80mA always networking mode

The scheme adopted in this scheme is the combination of alarm mode and networking mode

If each networking communication time is 2 minutes, the working time of one 10Ah battery is:

Calculation method:

Assuming that the network is connected all the time, the working time is 10000 / 80 = 125 hours = 7500 minutes = 3750 times

Assuming that the number of networking times per day is 10, the working time is 3750 times / (10 times / day) = 375 days

Assuming that it is always in the alarm mode, the consumption current of one year is: 33 * 24 * 365 UA = 289080ua = 289ma, accounting for about 1 / 34 of the total electricity