SENSECAP pH Sensor (S-pH-01) User Guide

: June 12, 2024
: SENSECAP

Table of Contents

Introduction
Wiring diagrams
Dimension
Installation Maintenance and Calibration
Output Signal Conversion
RS485 Modbus Protocol
Software Configuration Utility
Document Version
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

SENSECAP pH Sensor (S-pH-01) User Guide
$SENSECAP pH Sensor $S-pH-01$$

Introduction

S-PH-01 transmitter measures the PH of solution or semi-solid substrate. The output signal canbeRS485and Analog Voltage. The sensor is applicable for industrial, water processing, sewerage system, irrigation, smart agriculture etc.

Can be used for PH measurement
Output Interface with RS485, Voltage
High impedance and isolated electrode input
High accuracy with excellent stability
Reverse power protection and Built-in TVS/ESD protection

Specificatio ns

Output Interface| Analog Voltage 0-2V(Output resistance ~0ohm)| RS485 Modbus-RTU
Power Supply| 3.9-30V/DC| 3.9-30V/DC
Power Consumption| 35mA@24V DC| 35mA@24V DC
Start-up time| < 2 seconds
PH Measurement| High impedance and isolated input; Range: 0-14PH, Resolution: 0.01PH,Accuracy: +/-0.1PH; Can be used for solution or semi-solid substrate
Temperature Measurement (Option)| Range: -40~80°C, Resolution: 0.1°C, Accuracy: +/-0.5°C
IP Ratings| Electrode: IP68; Transmitter: IP65
Operating Temperature| -40~85°C
Installation| Electrode: 3/4″NPT screw threads; Transmitter: Mounting hole
Cable Length| Power and Signal Cable:2 meters or Customize; Electrode Cable: 5 meters
Dimension| Electrode: WidthDiameter 16030mm; 3/4″NPT screw threads Transmitter: 140mm65mm50mm

Wiring diagrams

Type	Wiring diagram
Analo g Voltag e Outpu t	Red (V+): Power Supply + Black (G): Power

Supply – Blue (O1): Analog Output
Wiring diagram
RS485 Modbus| Red (V+): Power Supply + Black (G): Power Supply – Yellow (T+): RS485+/A/T+ White (T-): RS485-/B/T-

Dimension

Electrode Dimension

Transmitter Dimension

*Note : Do not put the Transmitter into the liquid.

Installation Maintenance and Calibration

Installation

Installation locations of Electrodes will vary depending on the system design. The key is to monitor good representative sample of the whole solution directly after introduction of chlorine. The installation location must allow for complete contact of the scrubber liquid with the probes. Some example installation locations for Electrodes include the following:

Outlet of packed tower
Outlet of recycle pump
Pump bypass line
Heat Exchanger bypass line

Maintenance

Under normal conditions, electrodes can last anywhere from several months to several years depending on the type of operation, rate of production, strength of product, and quality of the raw materials used in the process.

Because each application is different, there is no average life expectancy. Because the pH responsive glass bulb or flat surface is relatively thin, care should be taken so that the bulb does not become scratched or broken. It is also important that ORP measuring surfaces are not
scratched or gouged. The suggestions in this sheet are intended to help avoid these problems. Coating of an electrode’s measuring surface can lead to erroneous readings including shortened span and wrest pones times. The type of coating determines the type of cleaning technique. Soft Coatings cambered moved by vigorous stirring, by use of a squirt bottle or, very carefully, by gently wiping with aloft, cleaning-abrasive paper or cloth. Hard Coatings should be chemically removed. The chemical used tore move the coating should be the least harsh chemical that dissolves the coating in 1 or 2 minutes undoes not attack the electrode’s materials of construction. For example, a calcium carbonate coating might be removed with 5% HCl (muriatic acid). Oily or Organic Coatings are best removed with detergents or an appropriate solvent that does not attack the electrode’s materials of construction. For example, isopropyl alcohol might be used but acetone should be avoided if the electrode’s body is made of CPVC.

Output Signal Conversion

PH output conversion

Output Interface	Parameters Range	Conversion Formula
Analog Voltage Output 0-2V	PH range: 0-14PH	PH=7.00*VOLTAGE.When

VOLTAGE=1.0V,then PH=7.00*1.00=7.
RS485 Modbus-RTU| PH range: 0-14PH| PH= (REGISTER VALUE)/100.When REGISTERVALUE=7000,then PH= 7000/100=7.00.
Temperature range: -40-80°C| TEMPERATURE= (REGISTERVALUE)/100.WhenREGISTER VALUE=2013,then TEMPERATURE= 2013/100=20.13°C.

NOTE: The unit of VOLTAGE is (V)

RS485 Modbus Protocol

Modbus Protocol

Modbus Protocol is widely used to establish master-slave communication between intelligent devices or sensors. A MODBUS message sent from a master to a slave contains the address of the slave, the function code (e.g. ‘read register’ or ‘write register’), the data, and a check sum (LRC or CRC).

The sensor is RS485 interface with Modbus protocol. The default serial communication setting is slave address 1, Modbus rut, 9600bps, 8 data bits and 1 stop bit. All communication settings can be changed with Modbus command, and take effective after re-power up the sensor.

Following Modbus function code are supported by sensor.

Modbus Function Code 0x03 : used for reading holding register. Modbus Function Code 0x04 : used for reading input register. Modbus Function Code 0x06 : used for writing single holding register. Modbus Function Code 0x10: used for writing multiple holding registe

Modbus Register

Parameters| Register Addr. (HEX/DEC)| Dat a Typ e| Modbu s Functio n Code(DEC)| Range and Comments| Defaul t Value
---|---|---|---|---|---
TEMPRATURE| 0x0000 /0| INT16RO| 3/4| -4000-8000 for -40.00~80.00°C.| N/A
PHPHVALUE| 0x0001 /1| UINT16RO| 3/4| 0-1400 for 0.00-14.00| N/A
| | | | |
TEMPCOMPENSA TEE N| 0x0020 /32| UINT16R/W| 3/6/16| 0: ExternalTemperature sensor 1: Disabled| 1
| | | | 2:On boardtemperature sensor|
| | | | |
PHCALIBRAWAD0| 0x0030 /48| UINT16| 3/6/16| -2000~2000| N/A
PH calibration| | R/W| | for –|
point for PH=4.01| | | | 2000~2000;|
| | | | Write 0xFFFF to|
| | | | calibrate.|
PHCALIBRAWAD1| 0x0031 /49| UINT16| 3/6/16| -2000~2000| N/A
PH calibration| | R/W| | for –|
point for PH=7.00| | | | 2000~2000;|
| | | | Write 0xFFFF to|
| | | | calibrate.|
PHCALIBRAWAD2| 0x0032 /50| UINT16| 3/6/16| -2000~2000| N/A
PH calibration| | R/W| | for –|
point for| | | | 2000~2000;|
PH=10.01| | | | Write 0xFFFF to|
| | | | calibrate.|
| | | | |
SLAVEADDRESS| 0x0200 /512| UINT16R/W| 3/6/16| 0-255| 1 or 12
BAUDRATE| 0x0201 /513| UINT16| 3/6/16| 0-6| 3:9600bps
| | R/W| | 0:1200bps|
| | | | 1:2400bps|
| | | | 2:4800bps|
| | | | 3:9600bps|
| | | | 4:19200bp|
| | | | s|
| | | | 5:38400bp|
| | | | s|
PROTOCOL| 0x0202 /514| UINT16R/W| 3/6/16| 0-10:Modbus RTU| 0:Modbu s RTU
PARITY| 0x0203 /515| UINT16| 3/6/16| 0-2| 0:Non
| | R/W| | 0:Non| e
| | | | e| Parity
| | | | 1:Eve|
| | | | n|
| | | | 2:Odd|
DATABITS| 0x0204 /516| UINT16| 3/6/16| 1| 1:8 databits
| | R/W| | 1:8 databits|
STOPBITS| 0x0205 /517| UINT16R/W| 3/6/16| 0-10:1 stopbit1:2 stopbits| 0:1 stopbit
RESPONSEDELAY| 0x0206 /518| UINT16R/W| 3/6/16| 0-255 for 0-2550milliseconds| 0
ACTIVEOUTPUTINTE RVAL| 0x0207 /519| UINT16R/W| 3/6/16| 0-255 for 0-255seconds.| 0

NOTE : UINT16:16 bit unsigned integer, INT16:16bit signed integer NOTE: RO: Register is Read Only, R/W: Register is Read/Write NOTE: HEX is Hexadecimal (data with 0x/0X prefix), DEC is Decimal

Modbus Register Detail Description

TEMPERATURE

Data Range| -4000-8000 For -40.00~80.00°C| Default: N/A
Power Down Save| N/A|

Note : Temperature value (Binary complement).
Example: When REGISTER = 0x0702 (HEX format), then
VALUE=(0x07256+0x02)/100=17.94°C.When REGISTER=FF05H (HEX format),then
VALUE=((0xFF256+0x05)-0xFFFF-0x01)/100 =(0xFF05-0xFFFF- 0x01)/100=-2.51°C.

PH VALUE

Data Range| 0-1400 for 0-14.00PH| Default: N/A
Power Down Save| N/A|

Note : PH value
Example: When REGISTER = 0x02BC (HEX format), then VALUE=(0x02*256+0xBC)/100=7.00PH

TEMPCOMPENSATEEN

Data Range| 0: External Temperature sensor 1: Disabled2:On board temperature sensor| Default: 1
Power Down Save| YES|

Note: Temperature compensation

PHCALIBRAWAD0

Data Range| -2000~2000| Default: N/A
Power Down Save| YES|

Note : PH calibration AD value for PH=4.01; Immerse the electrode into PH=4.01solutionand wait until the reading value being stable, then write 0xFFFF to this register to calibrate.

PHCALIBRAWAD1

Data Range| -2000~2000| Default: N/A
Power Down Save| YES|

Note : PH calibration AD value for PH=7.00; Immerse the electrode into PH=7.00solutionand wait until the reading value being stable ,then write 0xFFFF to this register to calibrate.

PHCALIBRAWAD

Data Range| 2000~2000| Default: N/A
Power Down Save| YES|

Note : PH calibration AD value for PH=10.01; Immerse the electrode into PH=10.01solutionand wait until the reading value being stable, then write 0xFFFF to this register to calibrate