Weighing Transmitter GM7702 User Manual.pdf

GM7702, a digital weighing transmitter with the standard dimension, is suitable for mounting on DIN rail in many industrial fields. Small size and flat compact design make it ideally integrate with whole weighing sector. Due to its high practicability, stability and easy operation, GM7702 can be widely applied to the industry of feeds, chemical, concrete and bitumen mixing, metallurgy smelting, etc..

1. GM7702
UserManual
GM7702-00180101
110607040003
VER01.00.12

2. ©2018,ShenzhenGeneralMeasureTechnologyCo.,Ltd
Thismanualissubjecttochangewithoutnoticeatanytimetoimprovetheproduct.No
partofthismanualcanbephotocopied,reproduced,ortranslatedintoanotherlanguage
withoutthepriorwrittenconsentoftheGeneralMeasureCompany.
Website:http://www.gmweighing.com
Implementationofstandards:GB/T7724—2008

3. TableofContents
1GeneralDescription.........................................................................-1-
1.1FunctionsandCharacteristics...............................................-1-
1.2FrontPanelDescription........................................................-2-
1.3Connectordiagram...............................................................-3-
1.4TechnicalSpecifications.......................................................-4-
1.4.1Common:...................................................................-4-
1.4.2Analog:......................................................................-4-
1.4.3Digital:......................................................................-4-
2InstallationandWiring....................................................................-6-
2.1ConnectionofPowerSupply.................................................-6-
2.2ConnectionofLoadCell......................................................-6-
2.3ConnectionofI/OTerminal..................................................-8-
2.4SerialPortOutput...............................................................-10-
2.5ConnectionofAnalog.........................................................-12-
3DataInputandParameters.............................................................-15-
3.1ParametersList...................................................................-15-

4. 3.2DataInput...........................................................................-20-
4.Calibration....................................................................................-22-
4.1Description.........................................................................-22-
4.2CalibrationParameter.........................................................-22-
4.2.1EmptyScaleCalibration.........................................-23-
4.2.2WeightCalibration..................................................-24-
4.2.3CalibrationwithoutWeight.....................................-25-
4.3CalibrationRecord.............................................................-26-
5ControlParameter..........................................................................-28-
6I/OModule.....................................................................................-31-
6.1I/OModuleDefine.............................................................-31-
6.2I/OModuleTest..................................................................-32-
7.PasswordManagement.................................................................-33-
8.SerialPortCommunication...........................................................-34-
8.1r-ContMode......................................................................-34-
8.2ModbusProtocol................................................................-35-
8.2.1ModbusAddress......................................................-36-

5. 8.3ModbusRTU、ModbusASCIIprotocol...........................-45-
8.4ChimeiPT650DProtocol..................................................-53-
9Dimension......................................................................................-55-

6. GM7702UserManual
-1-
1GeneralDescription
GM7702weighingindicatorisspeciallydesignedforweighttransmittinginindustrial
fields.Thisindicatorhasthefeaturesofsmallvolume,plentycommunicatingcommands,stable
performance,easyoperationandpracticability.Itcanbewidelyappliedtoconcreteandbitumen
mixingequipment,metallurgyfurnaceandconverter,chemicalindustryandfeed,etc..
1.1FunctionsandCharacteristics
smallvolume,uniquedesignandeasyoperation
applicabletoallkindsofresistancestraingaugebridgeloadcell
frontpanelnumericalcalibration
multilevelofdigitalfilter
automaticzero-tracking
automaticallyzerowhenpoweron
serialcommunicationinterface:RS232orRS485
calibrationviaserialinterface(SerialinterfacesetsON)
support16-bitresolutionDAoutput
2Inand3Out,supportlimitcontroloutput
onlineupgradeviaRS232serialport
tareweightfunction

7. GM7702UserManual
-2-
1.2FrontPanelDescription
Status:
 ZERO:Lightonwhenmaterialweightis0±1/4d.
 STAB:Lightonwhenmaterialweightiswithinstablerange.
 NET:Lightonwhenindicatorisinnetweightstatus.
 COM:Lightonwhenincommunicationstatus.
Keypad:
 ZERO/ESC:Usedtoexitfromcurrentoperationorgopreviouspage.
Inthestatusofnetweight,pressthiskeywillentergrossweightstatus.
 TARE:Inthestatusofgrossweight,pressOPTIONwilltareandindicatorshownet
weightvalue.
Whendatainput,themaindisplayflashandtheflashpositionwillmove.
 MODE：Tomakeflashingpositionmovetotherightdigitwhendatainputting.
 ENTER:Enteroptionwhencalibrationorinparametersettingandcanbeusedas

8. GM7702UserManual
-3-
analogswitchingdisplay.
1.3Connectordiagram

9. GM7702UserManual
-4-
1.4TechnicalSpecifications
1.4.1Common:
Powersupply:DC24V±5%
Workingtemperature:-10～40℃
Maxhumidity:90%R.Hwithoutdew
Powerconsumption:about0.8W
1.4.2Analog:
Loadcellpower:DC5V100mA（MAX）
Inputimpedance:10MΩ
Zerosteadyrange:0.00~12mV(Loadcell3mV/V)
Inputsensitivity:0.1uV/d
Inputrange:0.00～15mV(Loadcell3mV/V)
Transfermode:Sigma-Delta
A/Dconversionspeed:120/240/480times/sec.
Non-linearity:0.01%F.S
Gaindrift:10PPM/℃
Displayprecision:1/100000
1.4.3Digital:
Weightdisplay:128*320.91”WhitelightOLED
Minusdisplay:“-”
Overloaddisplay:Voltageoverlimit/underlimit

10. GM7702UserManual
-5-
Decimalpoint:5types(optional)
Functionkeys:4keyssoniferouskeypad

11. GM7702UserManual
-6-
2InstallationandWiring
2.1ConnectionofPowerSupply
GM7702weighingindicatorconnectswithDC24Vpowersupplyasfollows,whichhas
twolinesconnectingports.Thecorrectwiringofthepowerterminalisshowninthefigure
below:
2.2ConnectionofLoadCell
GM7702weighingindicatorconnectswithbridgetyperesistancestraingaugeloadcells
by4wires.(Whenuse6-wiredloadcells,youmustbridgetheEX+withSN+andbridgethe
EX-withSN-.)Itcouldconnectwithnomorethan4unitsloadcellof350Ω.
Eachportoftheloadcellconnectionterminalisallocatedas
Plea※Pleasepayattentiontothepositiveandnegativepolarityofthe
powersupply,donotconnectthereverse

12. GM7702UserManual
-7-
2.2.1LoadCellConnection
Note:
4wires EX+ EX- SG+ SG- SHLD

13. GM7702UserManual
-8-
1.Asloadcelloutputsignalissensitivetoelectronicnoise,thewiringshouldbeshieldcable
andseparatewithothercables,especiallyACpower.
2．4wiresconnectionissuitableforshortdistanceandstabletemperatureorlowprecision
field,otherwiseuse6wiresconnection.
3．Formoreloadcellsparallelconnection,theirsensitivity(mV/V)shouldbethesame.
2.3ConnectionofI/OTerminal
GM7702weighingindicatorhasequippedwithI/Omoduleof2INand3OUT.IN/OUT
functionusercanself-define.Tofacilitateuserswiringandsomespecialapplications,the
defaultdefinitionisasfollows
Output Input
OUT1 stable IN1 zero
OUT2 overlimit IN2 tare
OUT3 setpoint1

14. GM7702UserManual
-9-
Indicatorinputterminalconnection:
Indicatoroutputterminalconnection:

15. GM7702UserManual
-10-
2.4SerialPortOutput
GM7702weighingindicatorpossessesRS232andRS485serialport,whichsupport
Modbus-RTUprotocol,r-SP1,r-ContandChimeiPT650Dprotocol.
Communicationparameters:
Item Option Description
1.serialportRS232
2.serialportRS485
IDNo.
initialvalue:01;range:01-99.
baudrate
initialvalue:38400;option:9600,38400,
57600,115200.
dataformat
initialvalue:8-E-1;option:8-E-1,8-O-1,
8-N-1,7-E-1,7-O-1.
communication
Initialvalue:Modbus-RTU;option:
Modbus-RTU,r-Cont,
Modbus-RTU(2),Modbus-ASCII,PT650D.
ModbusHi-Lo
initialvalue:ABCD;option:ABCD(Hi-Lo),CD
AB(Lo-Hi)
sendinginterval
initialvalue:Nointerval;option:nointerval,
10msec,20msec,50msec.
datasendingintervalinr-Contmode
Theserialportinterfacedefinitiondiagramisshownontheleft
RS485Connectionmode:

16. GM7702UserManual
-11-
RS232Connectionmode:
9
pin
connector
25pin
connector
or
computer
Indicator

17. GM7702UserManual
-12-
2.5ConnectionofAnalog
Therearetwotypesofanalogoutput:
1)Voltageoutput:0-5V,0-10V.
2)Currentoutput:4-20mA.
3)User-definefunction:usercandefineanalogoutputtypeandoutputrange.
Analogparameter
Item Option Description
Workingmode
4-20mA
Weightvaluecouldbeconvertedtocurrentof
4-20mA.
0-5V
Weightvaluecouldbeconvertedtovoltageof0-5V.
0-10V
Weightvaluecouldbeconvertedtovoltageof0-10V.
user-defined
current
Usercandefinethecurrentorvoltage.
user-defined
voltage
Min.output
value
initialvalue:
00.000
Tosetmin.analogoutputvalue.(Thevaluewillnot
changeiftheconvertedvaluesmallerthansetvalue.)

18. GM7702UserManual
-13-
Zerooutput
value
initialvalue:
00.000
Tosetanalogoutputvalueofzeropointweightvalue.
Max.capacity
outputvalue
initialvalue:
00.000
Tosetanalogoutputvalueofmax.capacity.
Max.output
value
initialvalue:
00.000
Tosetmax.analogoutputvalue.(Itwillnotchangeif
convertedvaluebiggerthansetvalue.)
Analogoutputportsdefinedasbelow:
V+:Positivevoltageoutput；V-:Negativevoltageoutput
I+:Positivecurrentoutput；I-:Negativecurrentoutput

19. GM7702UserManual
-14-
Theindicatorhasbeencalibratedontheanalogoutputwhenitleavesthefactory,userno
needtocalibratetheanalogoutput.Iftheanalogoutputisabnormal,usercancalibratethe
analogoutputbyhimself(itisrecommendedtocalibrateundertheguidanceofaprofessional).
Calibrationmethod(useamultimetertoconnecttheanaloginterface):
※SelectcalibrationpointandpressENTER.Contactto
multimeterandinputthedisplayvalue,finallypress
ENTERtocomplete.
※Analogcalibrationhas4stepstocomplete.
ChangeoptionbypressingMODEkey.
1.Workingparameter
2.Calibrationparameter
1.4mAcalibration
2.12mAcalibration
3.20mAcalibration
4.24mAcalibration
※Inparameterinterface,pressingTAREandENTER3s
toenteranalogcalibration.

20. GM7702UserManual
-15-
3DataInputandParameters
3.1ParametersList
Inthestatusofweighing,usercouldenterparameterinterfacebyMODEkey,andchange
itembyTAREorMODE,thenpressENTERtoeditparameter.
Item
No.
Parameter Parameter
item
Description
1
Working
parameter
power-upzero
initialvalue:OFF(option:ON/OFF)
Toproceedzerojudgmentwhenpoweron.
zerotracking
range
initialvalue:0.(range:0~9d)
Automaticjudgmentofzeropointifweight
valueiswithinsettimeandrange.
zerotracking
time
initialvalue:1.0(0.0~9.9s)
Automaticjudgmentofzeropointifweight
valueiswithinsettimeandrange.
stablerange initialvalue:01.(range:00~99d)

21. GM7702UserManual
-16-
Stableifweightvaluechangeswithinset
timeandrange.
stabletime initialvalue:1.0.(Range:0.0~9.9s)
zerorange
initialvalue:01(1%~99%offullcapacity)
Zerorangeallowed.
digitalfilter
grade
initialvalue:5(Range:0~9)
Strongerfiltergrade,morestableweight
value.
stablefilter
grade
initialvalue:0(Range:0~9)
Toproceedsecondfilteronthebaseof
digitalfilter.
ADsamplerate
initialvalue:120times/sec.(120/240/480
times/sec.)
Tarememory
ON/OFF
Initialvalue:OFF(ON/OFFoptional)
Restorethetareweightbeforetheindicator
ispoweredon

22. GM7702UserManual
-17-
2 Calibration
unit
calibrationparameters
decimalpoint
division
max.capacity
remote
calibration
ON/OFF
calibration
withweight
calibration
withoutweight
3
Communicatio
nparameter
RS232
RS232/RS485parametersetting:
Including:IDno.,baudrate,dataformat,
communicationprotocol,MODBUSHi-Lo,
transferinterval(r-Contmode)
RS485
4 Control controlmode weightcontrolmode

23. GM7702UserManual
-18-
parameter parameter
setting
controlparametersetting
5
Analog
parameter
workingmodeTosetanalogoutputmode
min.output
value
Thevalueisdisplayedif
analogisbelowthisvalue.
Canbeset
in
user-define
dmode
zeropoint
outputvalue
Analogvaluewhenweight
valueiszero.
max.capacity
output
Theanalogvaluematches
withmax.capacityvalue.
max.output
value
Thevalueisdisplayedif
analogisoverthisvalue.
6 I/Odefine Defineinputandoutput
ports.
7 I/Otest Testinputandoutput
connectingports
8 Reset resetworking Resettofactorydefaults.

24. GM7702UserManual
-19-
parameter
resetserial
portparameter
Resettofactorydefaults.
resetall
parameters
Resettofactorydefaults.(exceptanalog
parameters)
9 Systeminfo.
password Passwordprotectionofallparametersor
changepassword.
language Languageversionchange.(Chinese/English)
automaticlock
screen
Theindicatorwilllockscreenautomaticallyif
therearenotanyoperationduringsettime.
(Option:OFF,1min.,2min.,5min.and
10min.)
Indicator
model
Settheindicatormodel(pressENTERto
ENTER,adjustmodelwithupanddown
selectionkeys.)
version Versioninformationdisplay

25. GM7702UserManual
-20-
compile
information
Versioncompilesinformationdisplay.
test Lightontocheckwhetheranydamageon
thescreenorindicatorlight.
3.2DataInput
Changeorinputofparametersvaluecouldbeproceedingthrough4functionkeys.
Changeofparameters:TARE—Upturn,MODE—Downturn,Enter—Confirm.
Parametervalueinput:TARE—valueplusone,MODE—changeposition,
1.Power-upzero
2.Zerotrackingrange
0：OFF
1：ON
0：OFF
1：ON
1.Power-upzero
2.Zerotrackingrange
PressENTERand
selectparameter
PressTAREor
MODEtoselect.PressENTERto
saveandcomplete
setting.

26. GM7702UserManual
-21-
ENTER—confirm.
3.Zerotrackingtime
4.Stablerange
1.0
1.0
2.0
3.Zerotrackingtime
4.Stablerange
PressENTERto
selectparameter
PressMODEto
changeinputposition
PressTAREtoadjust
inputposition.
PressENTERto
savesetting.

27. GM7702UserManual
-22-
4.Calibration
4.1Description
GM7702indicatorshouldproceedcalibratediftheparameterscan’tmeetusers’
requirement.Calibrationcanfixzeropointandgainvoltage.
Usercanmakerecordofcalibrationparametervalue,whichcouldbeusedincalibration
withoutweight.
4.2CalibrationParameter
Calibrationparameter Parameter Description
Unit g；kg；t；lb initialvalue:kg
Decimalpoint 0；0.0；0.000.000；0.0000initialvalue:0.00
Division 1；2；5；10；50 initialvalue:1
Max.capacity ≤division*100000 initialvalue:10000
Remotecalibration
ON/OFF
OFForON
Calibrationthroughserialport
whensetON.
Calibrationwith
weight
emptyscalecalibration
PressENTERkeyandsetpresent
statusaszeropoint.
weightvalue1 Theweightvalueisbaseofthe

28. GM7702UserManual
-23-
material.weightvalue2
weightvalue3
weightvalue4
Calibrationwithout
weight
zerocalibration Proceeding empty scale
calibrationandweightcalibration
ifurgent.
gainvoltagecalibration
gainweightcalibration
4.2.1EmptyScaleCalibration
Tosetemptyscaleaszeropoint
Weight: 2.100kg
Voltage: 1.843mV
Pressconfirmkey
（tosetpresentstatusaszero）
Weight: 0.000kg
Voltage: 1.843mV
Note:
※Thescalemustbeemptybeforepressing
ENTERkey.
※Emptyscalecalibrationcanonly
competedwhenstable.
※Pleaserecordvoltagevaluedisplayedin
emptyscalestatus.
※LongpressTAREkeyfor3seconds,can
manuallyinputmillivoltsforzerocalibration
withoutweight.

29. GM7702UserManual
-24-
4.2.2WeightCalibration
Inordertomeetthedemandsofmultipleweightstandards,usercouldsetparametersof
weightpoint1,weightpoint2,weightpoint3,weightpoint4,whicharehelpfultocalibrate
gainweight.
Weight: 0.000kg
Voltage: 0.000mV
Addingweight
Weight: 0.302kg
Voltage: 1.000mV
PressingENTER
Instatusofemptyscale,pressingconfirmkeyto
enterweightvalue1,displayweightandvoltage
willshow0.
Addingweights,alsorecordingbothweight
valueandvoltage

30. GM7702UserManual
-25-
Inputweightvalue
PressingENTER
tocompletecalibration.
Weight: 1.000kg
Voltage: 1.000mV
4.2.3CalibrationwithoutWeight
Thereisacertainerroravailableforcalibrationwithoutweight.Ifinurgentcondition,
pleasefollowbelowoperations.
Zerocalibration
01.843
Presszerocalibrationtoenter
zeromillivoltmanuallyinterface,
theninputthemillivoltof
calibrationwithweightrecord
andpressENTERtocomplete
PressingMODEkeycouldshiftsetpoint
position.PressOPTIONkeycouldedit
value.
Calibrationcompleted.

31. GM7702UserManual
-26-
Gainvoltage
calibration
00.000
Pressgainvoltagecalibrationto
entermanuallyinterface,then
inputthecalibrationwithweight
recordandpressENTERto
complete.
Gainweight
calibration
00.000
Pressgainweightcalibrationto
entermanuallyinterface,then
inputthegainvoltagecalibration
valueandpressENTERto
complete.
4.3CalibrationRecord
Forcalibrationofweights,pleaserecordzeromillivolts,gainmillivoltsandweightsinthe
attachedtable.Whenitisinconvenienttoloadweightsonsiteforsystemcalibration,thedatain
theattachedtablecanbeusedforthecalibrationwithoutweights
Table：
Times Zeromillivolts
(mV)
Gainmillivolts
(mV）
Weight Date Remark
1

32. GM7702UserManual
-27-
2
3
4

33. GM7702UserManual
-28-
5ControlParameter
GM7702hasequippedwithcontrollingexternalON/OFFstateparameters.controlling
mode:upper/lowerlimitmodeandsetpointmode.
Controllingparameters:
Mode Parameters Description
Upper/Lower
limit
outputstable
judgment
initialvalue:ON
Whetherlimitoutputproceededwhenstable.
min.duration initialvalue:0；range:0-99.9S；
upperlimit
value
initialvalue:0.Validwhenpresent
weightvalue>upperlimitvalue.(Define
OUTportasupperlimit)
Middle
limitvalid
when
lower
limit<pre
sent
weight<u
pperlimit
lowerlimit
value
initialvalue:0.Validwhenpresent
weightvalue<lowerlimitvalue.(Define
OUTportaslowerlimit)
Setpoint
mode
setpoint1
setpoint2
setpoint3
outputstable
judgment
initialvalue:ON
Whethersetpointoutputwhen
stable.

34. GM7702UserManual
-29-
setpoint4 min.duration initialvalue:0；Range:0-99.9S；
comparing
conditions
initialvalue:greaterthanorequal
to.Option:greaterthanorequal
to,lessthanorequalto,inthe
rangeoroutofrange.
presetvalue1
initial
value:0；
※Theindicator
willjudgepreset
value1whenthe
comparison
conditionisgreater
thanorequalto,less
thanorequalto.
presetvalue2
initial
value:0；
※Upperlimitvaluemustbegreaterthanlowerlimitvalue.
※Forexample,
1.Selectparameter:Upper/lowerlimitsettingmode,stablejudgmentwhenoutput:ON;min.
duration:2s.Upperlimit:1000.Lowerlimit:500.
I/Omoduledefinition:OUT1:upperlimit.OUT2:middlelimit.OUT3:lowerlimit.

35. GM7702UserManual
-30-
Loadweightmeteroutput:Beforetheweightisstable,theexternalswitchquantitymaintains
thestatebeforetheweightchange;whentheweightisstable,ifthecurrentweightisgreater
than1000,theoutputport1isvalid.Intheeffective2Stime,iftheweightisreducedto800in
stable,theoutputport1willcontinuetoremainvalidfor2seconds,andtheoutputport2will
bevalid.

36. GM7702UserManual
-31-
6I/OModule
6.1I/OModuleDefine
GM7702hasequippedwith2inputportsand3outputportsandcouldbedefinedfreely.
I/Omoduleparameters
Parameter Defineitem Description
IN-1
IN-2
0:nodefinition Whentheinputportisdefinedasthe
correspondingfunction,thetriggerinput
portisvalidandthefunctionisexecuted.
1:zero
2:tare
3:triggersetpoint1
4:triggersetpoint2
5:triggersetpoint3
6:triggersetpoint4
OUT-1
OUT-2
OUT-3
0:nodefinition Whentheoutputportisdefinedasthe
correspondingfunction,thetriggeroutput
portisvalid.
1:stable
2:overlimit
3:setpoint1output
4:setpoint2output
5:setpoint3output

37. GM7702UserManual
-32-
6:setpoint4output
7:upperlimit
8:middlelimit
9:lowerlimit
6.2I/OModuleTest
ThepurposeofI/Omoduletestistocheckwhethertheconnectioniscorrect.
I/Omoduletestparameters
Parameter Description
IN-1 OFF connectexternalswitchcorrectly(DC24V)
Whenexternaltriggerswitchisvalid,andinput
portparametersetson,meansconnectionis
already.
Iftheinput
andoutput
statusisnot
validas
preset,
check
whetherthe
wiringand
power
connections
arecorrect.
IN-2 OFF
OUT-1 OFF connectexternalswitchcorrectly(DC24V)
TopressENTERandsetparameterON.Output
indicatorlightisonatthesametime,means
connectalready.
OUT-2 OFF
OUT-3 OFF

38. GM7702UserManual
-33-
7.PasswordManagement
Passwordfunctioncanprotectindicatorparametersandcouldbeeditinsystem
informationparameter.
PasswordmustsetONandinputcorrectpasswordwhenenter.
Initialpassword:000000.
Parameter Description
PasswordON/OFF option:ON,OFF.UserhastoinputpasswordifsetON.
Changepassword
Thereis3steps:
1）inputoriginalpassword
2）inputnewpassword
3）inputnewpasswordagain
※Passwordinputmustbeinaccordance.

39. GM7702UserManual
-34-
8.SerialPortCommunication
GM7702hasoptionalRS232orRS485toconnectwithcomputer.Itsupportsr-Cont
protocol,r-SP1protocol,Modbus-RTUprotocol,ChimeiPT650Dprotocol.
8.1r-ContMode
Indicatorwilltransferdatatocomputerautomatically.
STX IDno.Channelno.Status Weight
value
CRC CR LF
02 2bytes 31 2bytes7bytes2bytes0D 0A
IDno.——2bytes,range:01~99
Status——2bytes,Highbyte:40H.Definitionoflowbyteasbelow:
D6 D5 D4 D3 D2 D1 D0
null null
G/N
weight
positive/
negative
zero OFL stable
fix:1fix:0
0:G
1:N
0:P
1:N
0:NZ
1:Zero
0:
Normal
1:OFL
0：
unstable
1:stable
Weightvalue——7byteswithoutsymbol,ifoverweightorunderweightandthenreturn,
indicatorwillshowOFL.
CRC——2bytes,checksum
CR ——1byte,0DH

40. GM7702UserManual
-35-
LF ——1byte,0AH
Forexample,
Indicatorisshowingbelowdata:02303131404120202037303032340D0A
Meanspresentstatus:grossweight,stable,positivevalue,weightvalueis700.
8.2ModbusProtocol
TheindictorcommunicatesinRTUmode,andeach8-bitbyteisdividedinto24-bit
hexadecimalcharactertransmissions
Functioncode:
Function
code
Definition Description
03 readregister
06 writesingle
register
16
write
multiple
registers
Allowtowritedoubleregistersonly.
01 readcoil
Unit:bit
05 writecoil

41. GM7702UserManual
-36-
Exceptioncoderesponse
Code Definition Description
02 illegaldataaddressItmeansthedataaddressreceivedisillegal.
03 illegaldata Thedatawroteinisillegal.
04 indicatorfault Indicatorfaultwhenoperation.
07 invalid Orderreceivedisinvalid.
8.2.1ModbusAddress
PLCaddr. Display
addr.
Description
Readonlyregister(functioncode:0x03)
40001 0000
presentweightvalue(4byteswithsymbol)
40002 0001
40003 0002 D0:stable
D1:zeropoint
D2:symbol
D3:overflow
D4:weightoverlimit
D5:weightunderlimit
D6:voltageoverlimit
D7:voltageunderlimit

42. GM7702UserManual
-37-
D8:stablemillivolt
D9:netweight
D10:beatstate,0-1alternateswitch,
1Hz
40004 0003
grossweightvalue
40005 0004
40006 0005
netweightvalue
40007 0006
40008 0007
tarevalue
40009 0008
40010 0009
ctarecurrentweight(floating-pointdata)
40011 0010
40012 0011
tarevgrossweight(floating-pointdata)
40013 0012
40014 0013
tarevnetweight(floating-pointdata)
40015 0014
40016 00015 D0:overrangewhenzeroing
D1:unstablewhenzeroing

43. GM7702UserManual
-38-
D2:overflowwhenzeroing
D3:zerocalibrationisunstable.
D4:zerovoltageistoohigh.
D5:zerovoltageistoolow.
D6:gainvoltageisunstable.
D7:gainvoltageistoolarge.
D8:gainvoltageistoolow.
D9:weightinputiswrong.
D10:calibrationresolutionistoolow.
D11:previousgainhasnotcalibrated.
D12:nonweightsforcalibration
40017 0016 grossweight(floating-pointdata)
40018 0017
40019-400200018-0019Reserved(Allowtoreadvalue:0)
Read&Write(writefunctioncode:0x06,0x10;readfunctioncode:0x03.)
40021 0020 unit:(0:g,1:kg,2:t,3:lb)
40022 0021 decimalpoint(0:0digit,1:1digit,2:2digits,3:3digits,4:4
digits)
40023 0022 division(1/2/5/10/20/50)
40024 0023
max.capacity,writerange(max.capacity≤division*100000)
40025 0024

44. GM7702UserManual
-39-
40026 0025 zerocalibrationwithweight:writenon-zerodataandcalibrate
zeropointwithpresentweightvalue,readabsolutemillivolt
ofpresentloadcell
40027 0026
40028 0027 gainpoint1calibrationwithweight,0≤weightvalue≤max.
capacity40029 0028
40030 0029 gainpoint2calibrationwithweight,gainpoint1≤weight
value≤max.capacity40031 0030
40032 0031 gainpoint3calibrationwithweight,gainpoint2≤weight
value≤max.capacity40033 0032
40034 0033 gainpoint4calibrationwithweight,gainpoint3≤weight
value≤max.capacity40035 0034
40036 0035 zerocalibrationwithoutweight:inputzeromillivolt.write
range(loadcell:3mV/V,range:0-12.000mV):readzeropoint
millivoltofcalibration
40037 0036
40038 0037 gaincalibrationwithoutweight,gain
millivoltinput
(0.000<millivolt<15.000mV-zeropoint
millivolt)
writein
sequenceto
complete
calibration
40039 0038
40040 0039 gaincalibrationwithoutweight;inputgain
weightvalue≤max.capacity40041 0040
40042-400500041-0049Reserved(allowtoreadvalue:0)

45. GM7702UserManual
-40-
40051 0050 auto-zerowhenpower-upON/OFF(0:OFF,1:ON)
40052 0051 zeropointtrackingrange(0-9d)
40053 0052 zeropointtrackingtime(0-9.9s)
40054 0053 stablerange(1-99d)
40055 0054 stabletime(0-9.9s)
40056 0055 zerorange(0%-99%)
40057 0056 digitalfilterparameter(0-9)
40058 0057 stablefilterlevel(0-9)
40059 0058 ADsamplerate:0:120times/sec.,1:240times/sec.,2:480
times/sec.
40060 0059 controlmode(0:upperandlowerlimitmode,1:presetpoint
mode)
40061 0060 Indicatormodel1
st
unit（“0”-“9”，“-”，“A”-“Z”）
40062 0061 Indicatormodel2ndunit（“0”-“9”，“-”，“A”-“Z”）
40063 0062 Indicatormodel3rdunit（“0”-“9”，“-”，“A”-“Z”）
40064 0063 Indicatormodel4thunit（“0”-“9”，“-”，“A”-“Z”）
40065 0064 Indicatormodel5thunit（“0”-“9”，“-”，“A”-“Z”）
40066 0065 Indicatormodel6thunit（“0”-“9”，“-”，“A”-“Z”）
40067 0066 TarememoryON/OFF(0:OFF,1:ON)

46. GM7702UserManual
-41-
40068-400700067-0069Reserved(allowtoreadvalue:0)
40071 0070 whetherjudgestablebeforeoutput(0:
OFF,1:ON)
upperlimit&
lowerlimit
mode
40072 0071 min.duration(0-99.9s)
40073 0072
upperlimitvalue(0-99999)
40074 0073
40075 0074
lowerlimitvalue(0-99999)
40076 0075
40077-400800076-0079Reserved(allowtoreadvalue:0)
40081 0080 Presetpoint1judgestable?(0:No,1:Yes)
40082 0081 presetpoint1min.durationtime(0-999:0-99.9s)
40083 0082 presetpoint1comparisoncondition(0:greaterorequalto,1:
smallerorequalto,2:withintherange,3:outsidetherange)
40084 0083
presetpoint1,presetvalue1
40085 0084
40086 0085
presetpoint1,presetvalue2
40087 0086
40088-400900087-0089Reserved(allowtoreadvalue:0)
40091 0090 presetpoint2judgestable?(0:No,1:Yes)
40092 0091 presetpoint2min.durationtime(0-999:0-99.9s)

47. GM7702UserManual
-42-
40093 0092 presetpoint2comparisoncondition(0:greaterorequalto,1:
smallerorequalto,2:withintherange,3:outsidetherange)
40094 0093
presetpoint2,presetvalue1
40095 0094
40096 0095
presetpoint2,presetvalue2
40097 0096
40098-401000097-0099Reserved(allowtoreadvalue:0)
40101 0100 Presetpoint3judgestable?(0:No,1:Yes)
40102 0101 presetpoint3min.durationtime(0-999:0-99.9s)
40103 0102 presetpoint3comparisoncondition(0:greaterorequalto,1:
smallerorequalto,2:withintherange,3:outsidetherange)
40104 0103
presetpoint3,presetvalue1
40105 0104
40106 0105
presetpoint3,presetvalue2
40107 0106
40108-401100107-0109Reserved(allowtoreadvalue:0)
40111 0110 presetpoint4judgestable?(0:No,1:Yes)
40112 0111 presetpoint4min.durationtime(0-999:0-99.9s)
40113 0112 presetpoint4comparisoncondition(0:greaterorequalto,1:
smallerorequalto,2:withintherange,3:outsidetherange)

48. GM7702UserManual
-43-
40114 0113
presetpoint4,presetvalue1
40115 0114
40116 0115
presetpoint4,presetvalue2
40117 0116
40118-401200117-0119Reserved(allowtoreadvalue:0)
40121 0120 IN-1define
Ifwrite2inaddress0120(IN-1),
meanstodefineIN-1astare
function.
40122 0121 IN-2define
40123 0122 OUT-1define
40124 0123 OUT-2define
40125 0124 OUT-3define
40126 0125 teststatus
Write1in0125addresstoenterI/O
moduletest.
40127 0126 inputtest
40128 0127 outputtest
40129-401500128-0149Reserved(allowtoreadvalue:0)
40151 0150 zero/cleartare read&writeaddress
write:1(zeroingrossweightstatus,
cleartareinnetweightstatus)
read:0
40152 0151
tare
40153 0152 IN-1status readonlyaddress:
1:valid-status40154 0153 IN-2status

49. GM7702UserManual
-44-
2:invalid-status40155 0154 OUT-1status
40156 0155 OUT-2status
40157 0156 OUT-3status
40158 0157 presetpoint1status
40159 0158 presetpoint2status
40160 0159 presetpoint3status
40161 0160 presetpoint4status
40162 0161 upperlimitstatus
40163 0162 middlelimitstatus
40164 0163 lowerlimitstatus
Read&Write(functioncodeofread:0x01,functioncodeofwrite:0x05)
00000 0000 zero/cleartare read&writeaddress:
write:1(zeroingrossweightstatus,
cleartareinnetweightstatus)
read:0
00001 0001 tare
00002 0002 IN-1status
readonlyaddress:
1:valid-status
2:invalid-status
00003 0003 IN-2status
00004 0004 OUT-1status
00005 0005 OUT-2status
00013 0012 OUT-3status

50. GM7702UserManual
-45-
00014 0013 presetpoint1status
00015 0014 presetpoint2status
00016 0015 presetpoint3status
00021 0020 presetpoint4status
00022 0021 upperlimitstatus
00023 0022 middlelimitstatus
00024 0023 lowerlimitstatus
00025~000320024~0031Reserved(allowtoreadvalue:0)
8.3ModbusRTU、ModbusASCIIprotocol
PLCAddressProtocolAddressDescription Remark
Fourbyteread-onlyregion（Supportedfunctioncode：03）
40001 0000
WeightValue
FourbytesighedNo.（Asa
complement）
WhenADiswrong：0x7F455252
（lower3bytesareE,R,R）
Whentheweightoverflows：
40002 0001

51. GM7702UserManual
-46-
0x7F4F464C（lower3bytesareO,F,L）
40003 0002
Status
bit0：0Unstable/1Stable
bit1：0Normal/1OFL
bit2：0NoneZero/1Zero
bit3：0positive/1Negative
bit4：0ADNormal/1ADwrong
bit5~bit31：0（standby）
40004 0003
40005 0004
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40006 0005
40007 0006
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40008 0007
40009 0008
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40010 0009
40011 0010 Reserved Thereservedbitdataisfixedas

52. GM7702UserManual
-47-
0x7F+'R'+'E'+'V'40012 0011
40013 0012
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40014 0013
40015 0014
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40016 0015
40017 0016
Weightvalue CurrentWeightValue
40018 0017
40019 0018
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'40020 0019
40021 0020
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'
40022 0021

53. GM7702UserManual
-48-
40023 0022
Reserved
Thereservedbitdataisfixedas
0x7F+'R'+'E'+'V'
40024 0023
40025 0024
Statusbit
Symbol：
bit0：0Unstable/1Stable
bit1：0Normal/1OFL
bit2：0NoneZero/1Zero
bit3：0positive/1Negative
bit4：0ADNormal/1ADwrong
Bit5~bit31：0（standby）
40026 0025
Twobyteread/writeregion（Supportedfunctioncode：03,06）
40101 0100 digitalfiltergrade
Theinitialvalue,rangeandspecific
meaningofeachparameterare
explainedSeechapter4
40102 0101 stablerange
40103 0102 stabletime
40104 0103 zero-trackingrange

54. GM7702UserManual
-49-
40105 0104 zerotrackingtime
40106 0105 zerorange
40107 0106 unit
40108 0107 decimalpointdigit
40109 0108 division
Fourbyteread/writeregion（Supportedfunctioncode：03,16）
40201 0200
Max.capacity writerange≤division×100000
40202 0201
40203 0202 weightzero
calibration
Writenon-zerovaluepairforzero
calibration.Readasthecurrentabsolute
millivoltnumber(fixed3-bitDecimal
point)
40204 0203
40205 0204 weightgain Writeweightvaluetoperformgain

55. GM7702UserManual
-50-
calibration
calibration.Thenumberofmillivolts
(signed)readoutasrelativezero(for
complement,fixed3decimalpoints)
40206 0205
40207 0206 Noweightzero
calibration
Thenumberofmillivoltswrittentothe
zeroposition.Readasthecurrentzero
millivoltnumber(fixedat3decimal
places).
40208 0207
40209 0208
Thenumberof
millivoltsofgain
writtenwhenthe
gainiscalibrated
withoutweight
Readas(gain
millivoltduring
calibration)(fixed3
decimalpoints)Read
as(gainweight
valueduring
calibration)
Bothcommands
mustbewritten
tocompletethe
gaincalibration
40210 0209
40211 0210
Theweightvalue
writtenwhenthe
gainiscalibrated
withoutweight
40212 0211
Byteonly（Supportedfunctioncode：01）
00301 0300 Stablemarker 0：Unstable；1：stable
00302 0301 OFLmarker 0：Normal；1：overflow

56. GM7702UserManual
-51-
00303 0302 Zeromarker 0：Non-zero；1：zero
00304 0303
Positiveand
Negativemarker
0：Positive；1：Negative
00305 0304 ADwrongmarker0：ADNormal；1：ADWrong
Byteread/write（Supportedfunctioncode：01,05）
00401 0400 Zerocalibration
Writeoperation:write1,zero
calibration;Write0,nooperationRead
operation:readas1,thedeviceisinzero
stateReadas0,thedeviceisina
non-zerostate
00402 0401 Reserved
Write:invalidandreturnsaddresserror
messageReadoperation:readasfixed0
00403 0402 Reserved
Write:invalidandreturnsaddresserror
messageReadoperation:readasfixed0
00404 0403 Reserved
Write:invalidandreturnsaddresserror
messageReadoperation:readasfixed0

57. GM7702UserManual
-52-
00405 0404 Zero
Writeoperation:write1,zero
calibration;Write0,nooperationRead
operation:readas1,thedeviceisinzero
stateReadas0,thedeviceisina
non-zerostate
00406 0405
Reserved
Write:invalidandreturnsaddresserror
messageReadoperation:readasfixed0
00407 0406
00408 0407
00409 0408
00410 0409
00411 0410
00412 0411
00413 0412 Systemrestart
Writeoperation:write1,system
restart;Write0,nooperationReadas:0
00414 0413 Resettodefaults
Writeoperation:write1,restorefactory
Settings;Write0,nooperationReadas:0

58. GM7702UserManual
-53-
00415 0414
ModbusHi-Lobyte
modeselection
Writeoperation:write1,lowbytemode
Write0,highbytemodeRead
operation:readas1,currentlyinlow
bytemodeRead0,currentlyinhighbyte
mode
8.4ChimeiPT650DProtocol
Protocoldescriptionsasfollow:
ProtocolchoosePT650D，dataframeformatadjustedto7-E-1，Baudrateadjustedto9600.
Underthisprotocol,dataisoutputbyASCIIcode,dataformatisasfollows:
Returnsadescriptionofthedataframeformat：
No.1234567891011122131415161718
0L,NT,-1234.57kgcLF
Note：

59. GM7702UserManual
-54-
No.1，2——Status1：
OL：overload；ST：stabledisplay；US：unstabledisplay
No.3——“，”2C（HEX)
No.4，5——Status2：
NT：NetWeight；GS：GrossWeight
No.6——“，”2C（HEX)
No.7——“+”：positive；“-”：negative
No.8-14——weightvalue：ifnodecimalpoint，outputaspaceatNo.8；overflowstatereadout
valueis999999
No.15-16——Unit：g，kg,t,lb
No.17-18——controlcode：CRLF

60. GM7702UserManual
-55-
9Dimension