Mod X0

I.Product Introduction

1.1 Product Overview

Mod X0 has one channel that can be connected to a flow sensor.It provides power supply,collects pulse signals,and calculates 

both instantaneous and total flow rates.The device supports read and write operations on registers via the standard Modbus-RTU 

communication protocol.It can be widely applied in various fields 

such as agricultural planting,water supply systems,industrial automation,the Internet of Things,drones,and smart homes.

1.2 Product Features

• Supports the standard Modbus-RTU communication protocol.

• Address,baud rate,reset to default parameters,query parameters,and settings can be modified and saved even after power loss.

• Built-in watchdog to prevent system crashes and a power-on indicator light.

• Wide input voltage range of DC 5-24V with protection against reverse connection,overvoltage,overcurrent,and short circuit.

• Protection against static electricity and lightning surges,with strong anti-interference capabilities.

• Comes with a PC-based testing software for convenient debugging,parameter configuration,and modification.

1.3 Product Highlights

• High-speed,high cost-effectiveness,high precision,high reliability,industrial-grade.

• Industrial-grade product that meets the usage requirements of different fields.

• Easy installation with standard C35(35mm)U-type universal rail mounting.

1.4 Product Specifications

• Power supply voltage:5-24VDC

• Power supply current:<20mA@24VDC

• Communication address:Station numbers from 1 to 255

• Baud rate:4800/9600/19200/115200 bps

• Communication distance:0-1200 meters,extendable via repeaters

• Parameter reset:Station number,baud rate

• Operating temperature:-20-60℃

• Installation method:Standard C35(35mm)U-type universal rail mounting

• Dimensions:855432(mm)

1.5 Wiring Diagram

• Upper Vin:Positive power input

• Upper GND:Negative power input

• Upper B:Negative end of the RS485 communication interface

• Upper A:Positive end of the RS485 communication interface

• Lower Vout:Positive power output(connect to the red wire of the flow sensor)

• Lower GND:Negative power output(connect to the black wire of the flow sensor)

• Lower FS 01:Flow signal input(connect to the yellow wire of the flow sensor)

• Lower FS 02:Not used

II.Communication Protocol

2.1 Instruction Table

The product uses the standard Modbus-RTU communication protocol and supports the following instructions:

• (1)Read Holding Registers Function Code:0X03(Hexadecimal)03(Decimal)

• (2)Write Single Holding Register Function Code:0X06(Hexadecimal)06(Decimal)

• (3)Write Multiple Holding Registers Function Code:0X10(Hexadecimal)16(Decimal)

The Modbus RTU register list is as follows:

 Function Code Chinese Name Register PLC Address Operation Type Operation Quantity

 0X03/03        Read Holding Registers 40001-49999 Word Operation Single or multiple

 0X06/06        Write Single Holding Register 40001-49999 Word Operation Single

 0X10/16        Write Multiple Holding Registers 40001-49999 Word Operation Multiple

2.2 Default Communication Parameters

• Address:1;

• Baud rate:9600bps;

• Data bits:8bit;

• Stop bits:1bit;

• Parity:None;

2.3 Holding Registers(Function Code 0X03)Definition

The host can read and write the parameters of the holding registers via the standard Modbus RTU protocol.

2.4 Communication Data Examples

Example 1:Read a Single Holding Register-Reading Instantaneous Flow

• Command:0x01 0x03 0x00 0x11 0x00 0x01 0xd4 0x0F(01 03 00 11 00 01 d4 0f)

• Station number:01

• Function code:03

• Starting address:00 11(decimal 17)

• Number of registers:00 01(one register)

• CRC check:D4 0F(low byte first,high byte second)

Note⚠️:The value read should be divided by 100 to get the actual instantaneous flow rate,in units of L/Min(liters per minute).

Example 2:Write a Single Holding Register-Changing Device Address to 2

• Command:0x01 0x06 0x00 0x01 0x00 0x02 0x59 0xCB(01 06 00 01 00 02 59 cb)

• Station number:01

• Function code:06

• Starting address:00 01(decimal 1)

• Target value of register:00 02(decimal 2)

• CRC check:59 CB(low byte first,high byte second)

2.5 Common Commands

• (1)Function:Change device address to 3

• Command:01 06 00 01 00 02 59 cb

(2)Function:Read instantaneous flow value

Command: 01 03 00 11 00 01 d4 0f

(3)Function:Reset permanent cumulative total flow to zero

Command: 01 10 00 04 00 04 08 00 00 00 00 00 00 00 00 47 B5

(Registers related to permanent cumulative flow need to be reset simultaneously,i.e.,registers 4/5/6/7 must be reset at the same time.)

(4)Function:Read permanent cumulative total flow

Command: 01 03 00 04 00 03 44 0A

(All commands can be obtained via the Modbus Debugging Assistant.

2.6 Hardware Reset

• Reset Button Location:Metal button on the circuit board,marked with the RESET label.

• Reset Range:Station number and baud rate.The station number is reset to 1,and the baud rate is reset to 9600.

• Operation Method:Power on while holding the RESET metal button,and continue pressing for 10 seconds.

2.7 Precautions

(1)After modifying the address,baud rate,K value,and permanent cumulative flow values,the device needs to be restarted 

for the changes to take effect.

(2)Before resetting the cumulative flow to zero,close the input pipeline to prevent water from passing through after the reset.

If the value changes within 60 seconds and the program modifies the value again,the cumulative flow may not be able to reset to zero.

(3)The temporary cumulative flow is reset to zero after power loss,while the permanent cumulative flow is recorded every 60 

seconds.(A flow change of more than 1 liter within 60 seconds is required for recording.)

(4)When the low byte of a register is full(65535),it increments the high byte by 1.For example,if the high byte of the cumulative flow 

for a flow sensor reads 1 and the low byte reads 2,the total flow is 655351+2=65537L.

(5)The maximum storage value for each register is 65535.The maximum storage data for the permanent cumulative flow of each flow

 sensor is 6553565535+65535=4,294,967,296 liters of water.

(6)During the reset operation,registers related to permanent cumulative flow must be reset simultaneously,i.e.,registers 4/5/6/7 

must be reset at the same time.The temporary cumulative flow reset should also follow this rule.

(7)If the station number and baud rate are forgotten,they can be restored to their factory values through hardware reset.

Power on while holding the RESET metal button and continue pressing for 10 seconds to restore the station number and baud rate 

to their factory settings.

III.Host Computer Software