JXCT JXBS-3001-PH-RS User manual

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RS485 Modbus
JXBS-3001-PH-RS Soil PH Sensor User Manual
JXBS-3001-PH-RS
Soil PH Sensor User Manual
RS485 Modubus
Version: 2.0
Date: 2020-10-24
Status: Released
www.jxct-iot.com

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RS485 Modbus
JXBS-3001-PH-RS Soil PH Sensor User Manual
I. Product Introduction
1.1 General Info
The transmitter is widely used in applications where pH value monitoring is
required, such as soil pH measurement. The input power supply, sensor probe,
and signal output of the sensor are completely isolated. Safe and reliable,
beautiful appearance and convenient installation.
1.2 Features
The probe of this product adopts PH electrode, with stable signal and high
precision. It has the characteristics of wide measurement range, good linearity,
good waterproof performance, easy to use, easy to install, and long
transmission distance.
1.3Main Specs
Specs
Content
Power Supply Default
12-24V DC
Consumption
≤0.15W
Detect Accuracy
±0.3pH
PH Detect Range
3-9pH
Long-term Stability
≤5%/year
Transmit Output
RS485Output (Modbus)
Working Temperature
0-55℃
Response Time
≤15s
1.4System Framework
This sensor can be connected to be used alone, firstly using 12V DC power
supply, the device can be directly connected to the PLC with 485 interface,
and can be connected to the single chip through the 485 interface chip. The
microcontroller and PLC can be used with the sensor by programming the
modbus protocol specified later. At the same time, use USB to 485 to connect
to the computer, and use the sensor configuration tool provided by our
company to configure and test.
Single Sensor Connection:

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This product can also be used by combining multiple sensors on one 485 bus.
Please observe the "485 Bus Field Wiring Code" (see appendix) when
performing 485 bus combination. In theory, a bus can connect more than 16
485 sensors. If you need to connect more 485 sensors, you can use a 485
repeater to expand more 485 devices. The other end is connected to a PLC
with a 485 interface through a 485 interface chip. Connect the single chip
microcomputer, or use USB to 485 to connect to the computer, use the sensor
configuration tool provided by our company to configure and test.
Multiple Sensors Connection:

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JXBS-3001-PH-RS Soil PH Sensor User Manual
II. Hardware Connection
2.1 Check before installation
Product List:
Name
Qty
Sensor
1Pc
12V Water-proof battery
1Pc(Optional)
USB to 485 Converter
1Pc(Optional)
Warranty
1Pc
2.2 Port Description
Wide voltage power input can be 12-24V. When connecting the 485 signal line,
please note that the two lines of A / B cannot be reversed, and the addresses
of multiple devices on the bus must not conflict.
Function
Cable Color
Specs
Power
Brown
Power supply +
Black
Power supply -
Communication
Yellow (grey)
485-A
Blue
485-B
Note: Please be careful not to connect the wrong wire sequence, the wrong
wiring will cause the device to burn.
The factory default provides 0.6 meters long wire, the customer can extend
the wire or connect according to the need.
Note that there may be no yellow line in the line sequence that may be
provided in some factory batches. In this case, the gray line is equivalent to
replace the yellow line.
2.3 Installation
Please note the following precautions:
1. Avoid installation in areas that are easy to transfer heat and directly cause
a temperature difference with the area to be measured, otherwise it will
cause inaccurate PH measurement.
2.Install in a stable environment, avoid direct sunlight, stay away from
windows and air-conditioning, heating and other equipment, and avoid
direct windows and doors.

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JXBS-3001-PH-RS Soil PH Sensor User Manual
III Configuration Software Installation
3.1 485 output mode sensor
Our company provides matching "sensor monitoring software", which can
easily read the parameters of the sensor using a computer, and flexibly modify
the device ID and address of the sensor.
3.1.1 Sensor connected to computer
After the sensor is correctly connected to the computer via USB to 485 and
provides power, you can see the correct COM port in the computer ("My
Computer-Properties-Device Manager-Port" to view the COM port).
As shown in the figure above, your serial number is COM10 at this time,
please remember this serial port, you need to fill in this serial number in the
sensor monitoring software.
If the COM port is not found in the device manager, it means that you have
not inserted the USB to 485 or installed the driver correctly, please contact the
technical staff for help.
3.1.2 Use of sensor monitoring software
The software interface is shown in the figure:

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RS485 Modbus
JXBS-3001-PH-RS Soil PH Sensor User Manual
After opening the software, first select the “Sensor Type” at the top of the
software, then obtain the serial number and select the correct serial port
according to the method in section 3.1.1, and then click “Automatically obtain
the current baud rate and address” to automatically detect All devices and
baud rates on the 485 bus. Please note that there is only one sensor on the
485 bus when using software for automatic acquisition. Then click "Connect
Device" to get sensor data information in real time.
3.1.3 Modify Baud Rate & Device Address
In the case of disconnecting "device connection", click "modify baud rate and
modify slave station number" in "configure sensor communication parameters"
to complete the relevant settings. Please note that after setting, please restart
the device, and then "automatically obtain the current "Baud Rate and
Address", you can find that the address and baud rate have been changed to
the address and baud rate you need.
IV Communication Protocol
4.1 Basic Specs

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Specs
Content
coding
8-bit binary
Data bit
8-bit
Parity bit
None
Stop bit
1-bit
Error calibration
CRC Long cyclic code
Baud rate
2400bps/4800bps/9600bps Optional.
Can Customize. Default is 9600bps
4.2 Data Frame Format Definition
Using Modbus-RTU communication protocol, the format is as follows:
Time for initial structure ≥ 4 bytes
Address code = 1 byte
Function code = 1 byte
Data area = N bytes
Error check = 16-bit CRC code
Time to end structure ≥ 4 bytes
Address code: It is the function indication of the transmitter. This transmitter
only uses the function code 0x06 (read register data).
Data area: The data area is the specific address, which is unique in the
communication network (factory default 0x01).
Function code: Command communication data sent by the host, pay
attention to the high byte of 16bits data first!
CRC code: two-byte check code.
Inquiry Frame
Address
Code
Function
Code
Register start
address
Register
length
Check digit
low
Check Digit
High
1bit
1bit
2bits
2bits
1bit
1bit
Reply Frame
Address
code
Function
code
Effective bit
number
First data
area
Second data
area
Nth data
area
1bit
1bit
2bits
2bits
2bits
2bits

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4.3 Register Address
4.4 Communication Protocol Example
4.4.1 Read the pH value of device address 0x01
Inquiry Frame
Address
code
Function
code
Starting
address
Data
Length
Check
digit low
Check digit
high
0x01
0x03
0x00
0x0d
0x00
0x01
0x15
0xC9
Reply frame (ie. Reading Value is 7.1pH)
Address
code
Function
code
Returns the
number of
valid bits
Data
area
Check
digit low
Check digit
high
0x01
0x03
0x02
0x00
0x47
0xD8
0x15
Explanation of pH calculation:
0047H (hexadecimal) = 71 => pH = 7.1pH
4.4.2 Read the pH value of device address 0x01
Inquiry Frame
Address
code
Function
code
Starting
address
Data
Length
Check
digit low
Check digit
high
0x01
0x03
0x00
0x06
0x00
0x01
0x64
0x0B
Reply Frame
Address
code
Function
code
Returns the
number of
valid bits
Data
area
Check
digit low
Check digit
high
0x01
0x03
0x02
0x01
0x34
0xD8
0x15
Explanation of pH calculation:
0047H (hexadecimal) = 308 => pH = 3.08pH
Register
address
PLC Configure
address
Content
Operation
0006H
40007
High precision pH Value
(0.01pH)
Read only
000dH
4000e
Low accuracy pH Value
(0.01pH)
Read only
0100H
40101
Device Address (0-252)
Read Write
0101H
40102
Baud rate
(2400/4800/9600)
Read Write