Daruifuno DPH7 User manual
Model: DPH7
Version 1.0
Daruifuno
Digital pH Sensor
User Manual
Contents
Chapter 1 Specification......................................................................1
Chapter 2 Basic Information..............................................................2
2.1 Security Information................................................................2
2.2 Overview..................................................................................2
2.3 Dimensions.............................................................................2
Chapter 3 Installation.........................................................................3
3.1 Sensor Installation...................................................................3
3.2 Sensor Wiring............................................................................4
Chapter 4 Communication..........................................................................5
4.1 Communication Protocol.................................................................5
4.2 Use.......................................................................................................6
4.2.1 Read Measuring Values.......................................................6
4.2.2 Modify Sensor Address...........................................................7
4.2.3 Sensor Calibration..........................................................................7
4.2.4 Reset Factory............................................................................7
Chapter 5 Maintenance.....................................................................8
5.1 Maintenance Cycle....................................................................8
5.2 Common Problems and Solutions...............................................................8
Appendix A Modbus Register Information..........................................................9
Our company seriously warrants each of the instrument for one year (12 months) from
the specific date of delivery. Consumables and consumable parts in the equipment are
not covered by the warranty. The terms of this warranty shall not apply if damage to the
instrument occurs beyond the warranty period, or in the opinion of the company, the
breakage or destruction of the instrument is due to improper use, lack of maintenance,
improper installation, improper modification, abnormal environmental conditions, etc.
The company's obligation under this warranty is limited to providing replacement or
repair of this product, as the case may be. The product must be thoroughly cleaned to
remove any contaminated chemicals before it is accepted for replacement or repair.
Our obligations shall not exceed the price of the product itself. In no event shall the
company be liable for damage caused by incidental or consequential damages,
whether to persons or objects. The company shall not be liable for any other loss,
damage or expense of any kind, including economic loss resulting from the installation,
use or improper use of the product.
For details, please refer to the product's quality promise with the product, and keep
this manual and the quality promise properly.
Guarantee
- 1 -
Measuring Principle
Glass Electrode Method
Measuring Range
0.00~14.00 pH 0.0~50.0 °C
Resolution
0.01 pH 0.1 °C
Accuracy
±0.02pH
Temperature Compensation
0 to 50°C, NTC automatic or manual
Calibration Method
Zero calibration, slope calibration, deviation calibration
Working Temperature
0 to 50°C
Working Pressure
≤2Bar
Protection Grade
IP68
Power Supply
9~36VDC
Power Consumption
About 0.2W
Electrical Isolation
Power and communication are isolated inside the sensor
Communication Interface
RS485 MODBUS
Shell Material
ABS
Sensor Dimension
φ35mm Total Length 260mm (including the cleaning cover)
Installation Dimension
One 1" NPT thread at the beginning and end Insertion depth
100mm (including cleaning connector 115mm)
Weight
About 150g(not including the cable)
Cable
PUR (polyurethane) sheath, standard 5 meters length can be
customized
Connect Method
Bare wire, M12 plug or waterproof aviation plug
Chapter 1 Specification
Product specifications are subject to change without notice.
Specification
- 2 -
Chapter 2 Basic Information
2.1 Security Information
Please read this manual completely before unpacking, installing and operating this
equipment. Pay special attention to all precautions. Otherwise, it may cause serious
personal injury to the operator or damage the equipment.
2.2 Overview
The digital pH sensor adopts the classic electrochemical principle, with reliable measurement
and stable performance. It is widely used in environmental protection water treatment, surface
water, purified water, circulating water and other systems, as well as electroplating, electronics,
printing and dyeing, chemical, food, pharmaceutical and other process fields. Excellent
performance in sewage treatment, drinking water treatment, surface water monitoring,
pollution source monitoring, industrial process and other applications.
2.3 Dimensions
Figure 1 Dimensions of the sensor
Basic Information
- 3 -
1-DN60 U-shaped card
7-M4 screw nut 8*4
2-U-shaped board
8-“8”shaped clip 25&32
3-Handle sleeve
9-M4 screw*25*2
4-DN40 U-shaped card
10-handle
5-M6 screw nut*8
11-DN32PVC Bracket
6-Rainproof elbow
12-1 inch inner wire straight pipe joint
Chapter 3 Installation
3.1 Sensor Installation
Refer to the pictures in this section to install and fix the sensor. To ensure that the sensor can
measure safely and accurately, the following conditions must be met during installation:
Choose a location that is convenient for operation and maintenance to install the sensor.
The pH sensor needs regular maintenance;
The electrode installation angle is within ±30°, and the electrode cannot be installed
horizontally or upside down;
Do not remove the protective cap when installing the electrode on site, and then remove
the protective cap after the installation is over.
Figure 2 Schematic diagram of railing installation
Installation
- 4 -
1-Flow cell
4-pH sensor fixed connection cover
2-Flow cell cover
5-dissolved oxygen sensor fixed connection cover
3-Turbidity sensor fixed connection cover
6-conductivity sensor fixed connection cover
Figure 3 Schematic diagram of five-parameter flow cell installation
Installation
Water outlet
Water overflow
water intake
3.2 Sensor Wiring
The sensor is correctly connected as defined in the table below.
Wire Color
red
black
white
green
Terminal Definition
Power positive
Power negative
RS485 data A (+)
RS485 data B (-)
Instrument Terminal Symbols
V+
V-
AS
BS
- 5 -
1
2
3
4
5
6
7
8
Slave
Address
Function
code
Register
starting
address
High 8 bit
Register
starting
address
Low 8 bit
Register
number
High 8 bit
Register
number
Low 8 bit
CRC
Low 8
bit
CRC
High 8 bit
1
2
3
4
5
5+n
5+n+1
5+n+2
5+n+3
Slave
Address
Function
code
Number of
data bytes
Data 1
high 8 bit
Data 1
Low 8 bit
Data n
high 8 bit
Data n
Low 8 bit
CRC
Low 8 bit
CRC
High 8
bit
Chapter 4 Communication
4.1 Communication Protocol
The instrument acts as a slave on the network and supports the Modbus RTU communication
protocol. The data communication is initiated by the host and the first byte of the transmitted
message is the target slave address. When the first byte is received by all slaves on the network,
each slave will decode it to determine whether the message is sent to itself.
The transmission of the RTU message frame starts with a pause interval of at least 3.5 characters.
After the last character is transmitted, a pause of at least 3.5 characters marks the end of the
message frame. A new message can start after this pause. In the transmission process, the entire
message frame must be transmitted in a continuous stream.
If there is a pause of more than 1.5 characters before the completion of the message frame
transmission, the receiving device will refresh the incomplete message and assume that the next
byte is the start of the new message. Similarly, if a new message starts after the previous message
frame in less than 3.5 character, the receiving device will assume that it is a continuation of the
previous frame, and this will cause an error because the last CRC value cannot be correct.
The host can send a command frame to read a single or all data results.The data frame format is
as follows (the data is all in Hex format)：
Host send：
Slave response:
Communication
- 6 -
4.2.1 Read Measuring Values
Read the pH value and temperature value measured by the sensor
(assuming the sensor address is 1)
Examples:
Send frame: [01 04 00 02 00 02 D0 0B], the meaning is as follows:
[01]: Slave address
[04]: Function code
[00 02]: The starting register address is 0x02
[00 02]: Read 2 registers starting from the starting address (that is, read
1single-precision floating-point data result)
[D0 0B]: CRC check data
Return frame: [01 04 04 CC CD 41 48 65 4D], the meaning is as follows:
[01]：salve address
[04]：function code
[04]：The number of bytes returned (here 4)
[00 00 41 C8] ：41 C8 00 00 (that is, the floating-point value is 25, the specific
meaning of the value is to find the corresponding address)
(Note: Combine two 16-bit integer registers to form a single-precision floating-point
number, pay attention to the order of the data)
Host sensds [01 04 00 02 00 04 50 09]
[01] Indicates the electrode address, where the electrode address is 1
[04] Indicates function code, here use function code 04 to read the measured value
[00 02] Indicates the starting register address, where the starting register address is 2
[00 04] Indicates the number of read registers, here 4 registers are read
[50 09] Represents CRC check code
Electrode return data [01 04 08 00 00 40 E0 00 00 41 C8 9A DD]
[01] Indicates the electrode address, where the electrode address is 1
[04] Indicates function code, here use function code 04 to read the measured value
[08] Indicates the number of data bytes, there are 8 bytes here
[00 00 40 E0] These 4 bytes represent the pH value, and the value is represented by a floating
point number, [00 00] is the low 16 bits, [40 E0] is the high 16 bits, that is, the 32-bit floating
point number is [40 E0 00 00 ], converted to a decimal number, it is 7, and the pH value is 7
[00 00 41 C8] These 4 bytes represent the temperature value, the value is represented by a
floating point number, [00 00] is the low 16 bits, [41 C8] is the high 16 bits, that is, the 32-bit
floating point number is [41 C8 00 00 ], converted to a decimal number, it is 25, and the
temperature value is 25 degrees Celsius
[9A DD] means CRC check code
4.2 Use
Use
- 7 -
4.2.2 Modify Sensor Address
Modify the electrode address, change the electrode address from 1 to 2
Host sends [01 06 00 00 00 02 08 0B]
4.2.3 Sensor Calibration
Electrode calibration (assuming electrode address is 1)
Zero calibration:
The calibration value is the value set at calibration point two, the default is 6.86
Use function code 16 to write value 7 to register address 206 to perform calibration
Host sends [01 10 00 CE 00 02 04 00 00 40 E0 4E 3B]
Slope one calibration:
The calibration value is the value set at calibration point one, the default is 4.01
Use function code 16 to write value 4 to register address 200 to perform calibration
Host sends [01 10 00 C8 00 02 04 00 00 40 80 CE 39]
Slope two calibration:
The calibration value is the value set at calibration point three, the default is 9.18
Use function code 16 to write value 9 to register address 214 to perform calibration
Host sends [01 10 00 D6 00 02 04 00 00 41 10 4F 45]
4.2.4 Reset Factory
Reset the factory (communication parameters are not reset) (assuming sensor address is 1)
Use the function code 06 to write the value 99 to the register address 400 to execute the recovery.
Host sends [01 06 01 90 00 63 C8 32]
Use
- 8 -
Chapter 5 Maintenance
In order to obtain the best measurement results, regular maintenance is required. Maintenance
includes cleaning of electrodes and checking for damage.
5.1 Maintenance Cycle
Maintenance Work
Maintenance frequency
Visual inspection
Every month
Check calibration
Every month (According to the environmental conditions of use)
Replace the pH sensor
Every year (According to the environmental conditions of use)
Seal maintenance
Every two years
5.1 Common problems and solutions
Problems
Solutions
Sensors cannot
communicate
1. Check whether the electrode wiring is correct
2. Check the communication setting parameters (address, baud rate,
parity bit, stop bit)
The measured value
is abnormal
1. Check whether the electrode bulb is cleaned and whether the
sensor is damaged
2. Restore the electrode to the factory calibration value, clean it and
recalibrate it with a standard buffer
3. Check the service life of the electrode
Maintenance
- 9 -
Appendix
Appendix A Modbus Register Information
Main measurement(use function code 04 to read)
Parameter
Address
Data format
Value range
Initial value
Instruction
Main measurement
2
32 Bit Float
0~14
-
Unit: pH
Temperature
measurement
4
32 Bit Float
0~50
-
Unit: ℃
Communication parameter(use function code 03 to read, function code 06 to write)
Parameter
Address
Data format
Value range
Initial value
Instruction
Address
0
Unsigned
1~254
9
-
Baud rate
1
Unsigned
0~3
1
0：4800
1：9600
2：19200
3：38400
Check digit
2
Unsigned
0~2
0
0：None
1：Even parity
2：Odd parity
Stop bit
3
Unsigned
1~2
1
1：1 bit
2：2 bit
System setting parameters(use function code 03 to read, function code 06 to write)
Parameter
Address
Data format
Value range
Initial value
Instruction
Sampling rate
4
Unsigned
0~4
2
0：Level 2 buffer
1：Level 4 buffer
2：Level 8 buffer
3：Level 16 buffer
4：Level 32 buffer
Temperature
mode
5
Unsigned
0~1
0
0：automatic
1：manual
Solution
compensation
type
6
Unsigned
0~3
0
0：no compensation
1：natural water
2：pure water
3：other
- 10 -
System setting parameters(use function code 03 to read, function code 06 to write)
Parameter
Address
Data format
Value range
Initial value
Instruction
Cal point 1
100
32 Bit Float
3.5<value≤4.51
4.01
The cal point value can be changed,
setting range: 3.5~4.51
Cal point 2
102
32 Bit Float
6.36<value≤7.5
6.86
The cal point value can be changed,
setting range: 6.36 ~7.5
Cal point 3
104
32 Bit Float
8.68<value≤10.
5
9.18
The cal point value can be changed,
setting range: 8.68 ~10.5
Zero point
106
32 Bit Float
-50~50
8.28
The zero value can be changed,
setting range: -50 ~ 50
Slope 1
108
32 Bit Float
45~60
59.16
The slope one value can be
changed, setting range: 45~60
Slope 2
110
32 Bit Float
45~60
59.16
The slope two value can be
changed, setting range: 45~60
Main measure
offset
112
32 Bit Float
-14~14
0
The main measurement offset value
can be changed, setting range:
-14~14
Temp offset
114
32 Bit Float
-100~100
0
The temperature offset value can be
changed, setting range:
Manual temp
value
116
32 Bit Float
0~100
25
Manual temperature value can be
changed, setting range: 0 ~100
Natural water
compensation
coefficient
120
32 Bit Float
0~1
0.008
The compensation coefficient value
can be changed, setting range: 0~1
Pure water
compensation
coefficient
122
32 Bit Float
0~1
0.015
The compensation coefficient value
can be changed, setting range: 0~1
Other solution
compensatio
coefficient
124
32 Bit Float
0~1
0.1
The compensation coefficient value
can be changed, setting range: 0~1
-100~100
User calibration parameters (use function code 03 to read, function code 16 to write)
Parameter
Address
Data format
Value range
Initial value
Instruction
Cal point1 Cal
200
32 Bit Float
-
-
Write value 4 for pH 4.01 calibration
Cal point2 Cal
206
32 Bit Float
-
-
Write value 7 for pH 6.86 calibration
Cal point3 Cal
214
32 Bit Float
-
-
Write value 9 for pH 9.18 calibration
Recovery (use function code 06 to write)
Parameter
Address
Data format
Value
range
Initial value
Instruction
Reset
setting
parameters
400
Unsigned
-
-
Write the value 99 to reset the setting
parameters, the communication setting
will not be reset
Appendix
Table of contents
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