User manualEnglish

GY-GD52 User Manual

This manual explains the photoelectric liquid detection principle, applications, specifications and wiring. It covers switching and RS485 output versions, Modbus RTU communication, register read/write examples, installation requirements and troubleshooting for integration into leak monitoring systems in server rooms and similar facilities.

GY-GD52 User Manual English.pdf

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ProductManual

Explosionproofphotoelectricwater

immersionsensor

ProductModel:GYGD52

Releasedate:August10,2026

Version:V1.0

DongguanYunjieIntelligentTechnologyCo.,Ltd.

1.ProductOverview

Understandthebasicinformation,characteristicsandworking

principleoftheproduct

Product

Overview

Thephotoelectricwaterimmersionsensorisappliedtothewater

leakagedetectionofthecomputerroom.Accordingtotheoptical

principle,itcanprovideveryaccurateandreliablewaterimmersion

measurement,whichissafe,reliable,easytoinstall,andnoteasyto

bedisplacedbyimpact.

Applicable

scenarios

Product

Features

Working

principle

Thephotoelectricwaterimmersionsensorworksbasedontheprincipleofinfraredlightrefraction,andits

corecomponentsincludeaninfraredlightemittingdiode(LED)andaphotosensitivereceiver.Whenthe

sensorprobeisinadrystate,thelightemittedbytheLEDistotallyreflectedbythelenstothereceiver;

Oncealiquid(suchaswater,oil,oraweaklycorrosivesolution)contactstheprobe,thelight

refractionpathchangesandthereceiversignaldropssharply,triggeringanalarmcircuit.

AboutourCOMPANYPROFILE

Warehouse

Factory

Pumproom

Archive

Data

Center

Datacenter

Highsensitivity

Alarmnotification

Stronganti

interference

Rapidresponse,alarmtime≤3seconds

Soundandlightdoublealarm,abnormalprompt

Resistenvironmentalinterferenceandreduce

misoperation

Easy

maintenance

Easytoinstall

Wide

compatibility

DIN35railinstallation

Removableforcleaning.Theleakdetectioncableisreusableafter

drying.

Supportaccesstothirdpartymonitoring

systems

2.technicalparameters

Productdetailedtechnicalspecificationsand

performanceindicators

Product

parameters

Version

Switching

quantity

Model

Supplyvoltage

Operating

current

Operating

temperature

Detection

accuracy

1mm(wateralarm1mmverticallydownward)

Outputsignal

Modbusprotocol485output

Powerindicator

light

Green

Alarmindicator

Red

Line

length

100cm±3cm(lengthcanbecustomized)

160cm±3cm(lengthcanbecustomized)

Wiring

Definitions

Redline:positive

Blackline:negative

Yellowline:publicend

Blue:Normallyclosed

(NC)

Whitewire:Normallyopen

(NO)

Redline:positiveinputpower

Blackwire:negativeinputpower

Yellowline:RS485A

Whiteline:RS485B

Waterproof

rating

Explosionproof

marking

parametersof

Explosionproof

certificate

Number

Thedataarealllaboratorymeasurements,butduetochangesintheobjectiveenvironment,thedata

willbeslightlybiased.

3.communicationprotocol

specification

ModbusRTUCommunicationInteraction

Standard

Basic

Agreement

Encoding

8bitbinary

Databit

8Bits

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paritybit

None

Stopbit

1st

place

errorcheck

CRC(RedundancyCheck)

Baudrate

2400/4800/9600/19200/38400/115200canbeset,factorydefault4800bit/s

Dataframeformatdefinition

UsingtheModbusRTUcommunicationprotocol,theformatisas

follows:

Initialstructure≥4bytesintime

Addresscode=1byte

Functioncode=1byte

DataArea=Nbytes

Errorchecking=16bitCRCcode

Endstructure≥4bytesoftime

Addresscode:istheaddressofthetransmitter,whichisuniqueinthecommunication

network(factorydefault0x01),thebroadcastaddressis0xFE,andthebroadcastaddress

canbeusedforqueryandsettingwhenthereisonlyonedeviceonthebus.

Functioncode:theinstructionfunctioninstructionissuedbythehost,thistransmitteronly

usesfunctioncode0x03(readregisterdata)andfunctioncode0x06(writeregisterdata).

Dataarea:Thedataareaisspecificcommunicationdata.Notethatthehighbyteof16bitsdataisfirst!

CRCcode:atwobytecheckcode.

Hostinquiryframestructure:

Address

code

Function

code

lowbitofcheck

code

Highbitofcheck

code

1byte

2bytes

1byte

Slightanswerframestructure:

Address

code

Function

code

Numberofvalid

bytes

DataArea1

Seconddataarea

DataAreaN

1byte

2bytes

Slightanswerframestructure:

Content

Operation

Description

Devicestatus

Read

only

Datareadas0:Devicestatuspositive

often

Value1:floodalarm

Value2:WaterImmersion

Fault

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Content

Operation

Description

Deviceaddress

Read/

Write

Deviceaddressrange:1253

Devicecommunication

baudrate

Read/

Write

Setthebaudrate,16respectively,asshown

down

Whentheequipment

delaysthealarm

space

Read/

Write

065535seconds

Queryusingthe

command

1.Example:Readthedevicestatusinquiryframeofdeviceaddress0x01(hexadecimal):

Address

code

Function

code

StartAddress

Datalength

lowbitofcheck

code

Highbitofcheck

code

Devicenormalresponseframe(hex):

Address

code

Function

code

StartAddress

Datalength

lowbitofcheck

code

Highbitofcheck

code

Devicealarmresponseframe(hex):

Address

code

Function

code

Returnsthenumberof

validbytes

Data

lowbitofcheck

code

Highbitofcheck

code

Devicefailureresponseframe(hex):

Address

code

Function

code

Returnsthenumberof

validbytes

Data

lowbitofcheck

code

Highbitofcheck

code

2.Readthedeviceaddressinquiryframeofdeviceaddress0x01(hexadecimal):

Address

code

Function

code

StartAddress

Datalength

lowbitofcheck

code

Highbitofcheck

code

Replyframe(hexadecimal):Deviceaddressvaluebit1

Address

code

Function

code

Returnsthenumberof

validbytes

Data

lowbitofcheck

code

Highbitofcheck

code

3.Readthedevicecommunicationbaudrateinquiryframe(hexadecimal)withdeviceaddress0x01:

Address

code

Function

code

StartAddress

Datalength

lowbitofcheck

code

Highbitofcheck

code

AboutourICOMPANYPROFILE

Answerframe(hexadecimal):baudratevalueof3is9600

Address

code

Function

code

Returnsthenumberof

validbytes

Data

lowbitofcheck

code

Verification

code

High

4.Readtheequipmentdelayalarmtimeinquiryframewithequipmentaddress0x01(hexadecimal):

Address

code

Function

code

StartAddress

Datalength

lowbitofcheck

code

Highbitofcheck

code

Answerframe(hexadecimal):delayalarmtimeis0(default)

Function

code

Returnsthenumberof

validbytes

Data

lowbitofcheck

code

Highbitofcheck

code

5.Setthedeviceaddressvalueofdeviceaddress0x01to2inquiryframes(hexadecimal):

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

Answerframe(hexadecimal):setsuccessfully

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

6.Setthedevicecommunicationbaudrateofdeviceaddress0x01to19200inquiryframe(hexadecimal):

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

Answerframe(hexadecimal):setsuccessfully

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

7.Settheequipmentdelayalarmtimeofequipmentaddress0x01to3inquiryframes(hexadecimal):

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

Answerframe(hexadecimal):setsuccessfully

Address

code

Function

code

Data

lowbitofcheck

code

Highbitofcheck

code

Commonproblemsandsolutions

Possiblecausesofnooutputoroutputerrors:

ThecomputerhasaCOMmouth,andthemouthselectedis

incorrect.

Thebaudrateiswrong.

The485busisdisconnected,ortheandBlinesareconnected

reversely.

AboutourCOMPANYPROFILE

Address

code

Iftherearetoomanydevicesorthewiringistoolong,supplypowernearby,adda485booster,andincreasethe120Ωterminalresistance.

TheUSB485driverisnotinstalledorisdamaged.

Damagetoequipment.

4.installationmethod

Standardizetheinstallationprocessandlowerthe

operatingthreshold

Itshouldgenerallybeinstalledinlowlyingareaspronetowaterimmersionorinsidewater

containingcontainers,andcanbemountedeitherhorizontallyorvertically.Whenitisusedfor

thefloodalarmundertheisolationfloorofthemachineroom,thegroundisfixedwithround

nails,andthentiedwithPVCcableties.Whenitisusedforindoorcabletrenches,itisdirectly

tiedwithPVCcabletiesonthecrossbraceorthickcables.

Installationprecautions

Groundcleaning:cleanupdustandoilonthegroundbeforeinstallationtoensuregoodcontactbetweentheprobe

andtheground.

Fixfirmly:thesensorandcableshallbefixedwithbuckleoradhesivetapetopreventdisplacement.

Avoidfalsepositives:Donotinstallinplaceswherewaterstainsandcondensateoftenoccur(suchasdirectlybelowtheair

outletoftheairconditioner).

Wiringspecification:powerlinesandsignallinesawayfromstrongcablestoavoid

interference.

Waterprooftreatment:theterminaliswaterproofandsealedtopreventpoorcontactcausedbywatervapor

corrosion.

ProductSize(Unit:mm)

Shellmaterial:zincalloydimensions:47*30mm

AboutourCOMPANYPROFILE

AboutourICOMPANYPROFILE

Readabletextreferenceforsmalllabels

Sourcepage2

Warehouse

Sourcepage2

Factory

Sourcepage2

Pumproom

Sourcepage2

DataCenter

Sourcepage2

Highsensitivity

Sourcepage2

Alarmnotification

Sourcepage2

Strongantiinterference

Sourcepage2

Rapidresponse,alarmtime≤3seconds

Sourcepage2

Soundandlightdoublealarm,abnormalprompt

Sourcepage2

Resistenvironmentalinterferenceandreducemisoperation

Sourcepage2

Easymaintenance

Sourcepage2

Easytoinstall

Sourcepage2

Widecompatibility

Sourcepage2

DIN35railinstallation

Sourcepage2

Removableforcleaning.Theleakdetectioncableisreusableafterdrying.

Sourcepage2

Supportaccesstothirdpartymonitoringsystems

Sourcepage3

Switchingquantity

Sourcepage3

Operatingcurrent

Sourcepage3

Operatingtemperature

Sourcepage3

Detectionaccuracy

Sourcepage3

Powerindicatorlight

Sourcepage3

Linelength

Sourcepage3

WiringDefinitions

Sourcepage3

Blackline:negative

Sourcepage3

Yellowline:publicend

Sourcepage3

Blue:Normallyclosed(NC)

Sourcepage3

Whitewire:Normallyopen(NO)

Sourcepage3

Waterproofrating

Sourcepage3

Explosionproofmarking

Sourcepage3

Explosionproofcertificate

Sourcepage3

Number

Sourcepage3

Encoding

Sourcepage4

None

Sourcepage4

1stplace

Sourcepage4

Addresscode

Sourcepage4

Functioncode

Sourcepage4

lowbitofcheckcode

Sourcepage4

Highbitofcheckcode

Sourcepage4

Addresscode

Sourcepage4

Functioncode

Sourcepage4

Numberofvalidbytes

Sourcepage4

Operation

Sourcepage4

Description

Sourcepage4

Readonly

Sourcepage4

often

Sourcepage4

Value2:WaterImmersionFault

Sourcepage5

Operation

Sourcepage5

Description

Sourcepage5

Deviceaddress

Sourcepage5

Read/Write

Sourcepage5

Devicecommunicationbaudrate

Sourcepage5

Read/Write

Sourcepage5

Setthebaudrate,16respectively,asshownin

Sourcepage5

down

Sourcepage5

Whentheequipmentdelaysthealarm

Sourcepage5

space

Sourcepage5

Read/Write

Sourcepage5

065535seconds

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

Returnsthenumberofvalidbytes

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

Returnsthenumberofvalidbytes

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

Returnsthenumberofvalidbytes

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage5

Addresscode

Sourcepage5

Functioncode

Sourcepage5

lowbitofcheckcode

Sourcepage5

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

Returnsthenumberofvalidbytes

Sourcepage6

lowbitofcheckcode

Sourcepage6

Verificationcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Functioncode

Sourcepage6

Returnsthenumberofvalidbytes

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode

Sourcepage6

Functioncode

Sourcepage6

lowbitofcheckcode

Sourcepage6

Highbitofcheckcode

Sourcepage6

Addresscode