dataTaker

dataTaker...keeping an eye on reality

dataTaker Training Course• dataTaker 50• dataTaker 500• dataTaker 505• dataTaker 60• dataTaker 605

Interfacing and Connecting Sensors

Block Diagram101+-+ṞR1 + -R2+-R5 or 10+ -RChannelExpansionModuleSE RefAnalogInputMultiplexer* DT500/600series(not Isolated) NetworkDigitalInputs1 to 20DigitalOutputs1 to 10Voltage andCurrent Sourcesfor ExcitationSignalConditioningMode SelectChannel SelectRealTimeClockDigitalComparatorVoltageRegulatorsPrecisionVoltageReferencesGuardMicroprocessor64180Signal I/O BoardBattery ChargerInstrumentationAmplifierGainSelectAnalog todigitalConverter+5V swBattery9 -18 VAC11 - 24 VDCDigitalInput/OutputsGNDD1D2D3D4Processor BoardC1C2C3C1 outInternalData Store64KCMOS RAM1MByteEPROMRemovablePCMCIA Card512K - 1MBytesDisplay/KeypadModuleRS232COMMSHigh Speed Counters* Isolated to500Volts (series 2)

Powering

Powering - DT50Datataker 509 to 18 Volts AC11 to 24 Volts DC~ ~ GNDPrefered positivefrom power supplyBATTERYAlkaline Lead Acid(9V) (6V)+ - +

Powering - DT500,600Datataker 500, 600 seriesPrefered positivefrom power supplyBatteryAlkalineNegativeLead Acid+-+Internal Battery Connector+ Batt AC/DC GND9 to 18 Volts AC11 to 24 Volts DC

PoweringPower Supply Voltage:11 - 24 VDC, 9 - 18 VACPower Source Condition Current (typical)Battery Awake 100mABattery Sleep 0.36mAAC/DC Awake & charging 600mAAC/DC Sleep 5mAAC/DC Sleep & charging 500mA6V 1.2 AHr gel cell6V 4 AHr gel cell9V 17 AHr alkaline15 Days at 1 scan/min45 Days at 1 scan/min200 Days at 1 can/min

PoweringThe external power supply can be 12VAC or 12VDC power adapter from mains large 12V battery set 12V solar panel, 10 Watt recommendedThe external AC/DC power power input provides primarypower supply when availableThe external AC/DC power input also provides recharging ofthe gel cell internal battery. Recharging is temperaturecompensated, to 6.90 VDC and current limited to 1A

Internal BatteryThe ‘internal’ battery of the DT50 is physically outside of thechassis of the logger, and can be either 6 Volt gel cell, usually 4Ahr 9 Volt alkaline, 17AhrThe internal battery of the DT500 and DT600 loggers can beinside or outside the chassis of the logger, and can be either 6 Volt gel cell inside of logger, 1.2Ahr capacity 6 Volt gel cell outside of logger, usually 4Ahr 9 Volt alkaline, 17AhrThat there is a different connection for the two battery typesOnly the gel cell batteries are recharged

Power ModesThe dataTaker has three power modes, which determine howthe logger manages its power consumptionParameter 15Sleep ConditionP15=0 Sleep only if not busy and battery poweredP15=1 Sleep if not busyP15=2 Disable sleepDefault power mode is P15=0 where logger will remain awake if externally powered logger will sleep if battery powered

Power ModesIf set P15=1, the logger will automatically sleep whenpossible even with external power connected. This mode isappropriate to powering from an external battery or solarpanel.If set P15=2, then logger will never sleepIn sleeping modes, the logger will automatically sleep whenthere is no scanning or communications sleeps immediately after a scan sleeps 30 seconds (P17=30) after communication,memorycard insertion or display keypad pressedLogger wakes on scan trigger, communication, memory card

Sensor Power Supplies5V Switched Output (Regulated,100 mA max)Battery5VoltRegulator5V+5V SWwakeDatatakerG

Sensor Power SuppliesChannel Excite Output (4.5 volt, Unregulated)5 volts1K4 voltsDatatakerN/C2.5mA2504.5VguardSelectorIIIVGProtectionResistorsMultiplexersR

Communications

Communication Interfaces• Host Communications RS232 serial interface, full duplex Baud Rate - 300, 1200, 2400, 4800 & 9600 Electrically isolated to 500Volts Bi-directional XON/XOFF protocol Selectable high level protocol with 16-bit CRC checking• Network (DT500 & 600 series) Up to 32 Loggers Separate RS485 interface, error correcting protocol Twisted pair cable, 1000 metres maximum

RS232 Serial InterfaceDatatakerDE 9 Male987654321RxDTxDGNDShieldYellowBlueGreenIBM ATDE 9 Female32578TxDRxDGNDRTSCTS6DSR1DCDSeries 1 loggers - RS232 NOT isolatedSeries 2 loggers - RS232 isolated to 500 Volt4DTR

Isolating RS232 Serial Interface (Series 1 Only)(Not Available DT50)IsolationInterface PowerWakeRx+RxTxInterface CommonDatataker+6V outLogger groundDatatakerDE 9 Male7564312YellowBlueGreen987654321RxDTxDGNDPower6-12V, 10mAShieldDT500/600 series COMMSinterface has an isolated internalpower supply, with extra antiphaseoutput to support theRS432 standardNot required for DTxx5 modelsYellowBlueGreen32578614TxDRxDGNDRTSCTSDSRDCDDTRIBM ATDE9 Female

RS232 ParametersThe RS232 communication port parameters are fixed, withthe exception of the baud rateBaud Rate 300, 1200, 2400, 4800, 9600Data Bits 8Parity noneStop Bits 1Flow Control XON/XOFF

Setting RS232 Parametersx = don't careDatataker500/600 series1 2 3 4 5 6 7 8ONBaud RateBaud Rate sw2 sw31200 off off9600 off on300 off on24004800ononoffonsw4xoffonxxNote differentswitch numbersDatataker 501 2 3 4 5 6 7 8ONBaud RateBaud Rate sw2 sw3 sw51200 off off x9600 off on off300 off on on2400 on off x4800 on on x

Interfacing to ModemsThe DT50/500/600 series loggers have no modem controllines to support smart modem usageHowever modems can be used with these loggers at aremote site to program the logger return realtime data unload logged dataThe DT50/500/600 series loggers cannot dial out from a siteto a central hostThe dataTaker Modem Manager can be used with loggers atremote sites to call in alarm states to a central host

Modem TypesAll modem types can be used with loggers at remote sitesPSTN (telephone network) modems require a landline to site $120 - 150 AC powered $300 - 500 DC poweredGSM (cellular network) modems Siemens M20, Wavecom WM02 limited to areas serviced by cells $800 + SIM card

Modem TypesRadio modems Freewave, Elpro 900MHz spread spectrum require line of site between transmitter and receiver $2600 - 6000 per pairSatellite limited communications volume geosynch - can be accessed at any time orbital - limited access time $4000+

Modem PowerRemote sites often only have a limited DC power supplyavailable, therefore require a DC powered modem most modems are 9VAC DC powered modems include Banksia IG6000 dataTaker P1414MX Pocket ModemModem power consumption is generally very high (>200mA)Modems generally do not have ‘sleep’ modes to reducequiescent power consumption when on hookIdeally require a modem which powers down when on hook,and powers up on first incoming ring

Modem PowerThe dataTaker can be configured to power the modem up fora window of time each day (or more) reduces power consumption limits access to the site to the window of time(s)Wire in a relay which switches power to the modem is controlled by a digital channel of the logger is normally open, because the coil will power down if thelogger sleeps

Modem PowerThe commandIFR1(T>

Modem PowerPSTN modems are prone to ‘locking up’ due to powerfluctuations and line noiseGSM and radio modems are more tolerantGood practice to have dataTaker power the modem down atleast once per dayThis will force modem to do a reset, to reload its configurationprofile, and recover functionality

Configuring the dataTakerSet the dataTaker baud rate as follows if using an older PSTN modem which has slower baudrates(300, 1200, 2400, 4800) then set the dataTaker baud rateto match the modem baud rate if using newer PSTN modem with higher baud rates then Series 1 dataTakers - set baud rate to 4800 baud Series 2 dataTakers - set baud rate to 9600 baud if using GSM modem, then set baud rate equal to the baudrate of the data link. This will be either 4800 baud or 9600baud depending on telecommunications carrier if using radio modems then use 4800 baud (Series 1) or9600 baud (Series 2)

Configuring the dataTakerThe dataTaker must be configured not to communicate withthe modem while the modem is on hook (no call in progress) /eno echo /rno real time data /mno error messages /zno alarm action messagesThese switches are automatically managed by DeTransferand DeLogger issue /E/R/M/Z following successful connection issue /e/r/m/z immediately prior to disconnection

Configuring the dataTakerThe dataTaker password should also be implemented to ignore any random characters issued by the modemdue to line noise, power down / power up, etc. while onhook to block hackers (!!)Set password by the commandPASSWORD=“password”DeTransfer and DeLogger 4 can issue the password duringconnection. DeLogger 3 does not support the password.

Configuring the ModemSet the baud rate of the modem RS232 port to match thebaud rate setting of the dataTaker. Also disable auto-bauding.Depending on the modem, baud rate may be set by DIPswitch, by a setup menu, or by commandCommands to set baud rate vary considerably betweenmodems - consult your modem manual for detailsMake sure that the modem RS232 parameters match thedataTaker for No parity, 8 data bits, 1 stop bit, XON/XOFFflow control (these are fixed in the dataTaker)

Configuring the ModemThe modem must also be configured to not communicatewhile it is on hook (no call in progress) AT&F restore factory defaults ATE0 no command echo ATQ1 quiet mode - no response codes various enable pass through XON/XOFF various disable auto-bauding/speed conversion ATS0=2 answer calls after 2 rings AT&W0 save this profile in user profile memoryThese commands can be entered via a generic connectionwith DeTransfer, Windows Hyperterminal, etc.

Connect dataTaker and ModemWhen the dataTaker and modem have been configured, thenconnect these together with a MOD-3 cableIf a PSTN modem, then connect PSTN line to the modemIf possible, test the functionality in a location where there aretwo phone lines. Also set up the PC and its modem, andmake test calls to the dataTaker - modem assembly

Calling Remote SiteDeTransfer and DeLogger 4 use the local modem (themodem connected to the PC) via the Windows TAPI, and sothe local modem must be installed via Windows ModemWizardDeLogger 3 does not use the Windows TAPI must explicitly define modem initialization commandsin modem settings of DeLogger 3 refer to modem users manual for details of settingsrequired when modem is used with WindowsConnect to the site and test the functionality of allcomponents

TroubleshootingIf you cannot connect to the remote site, most likely causesare incorrect baud rate settings between remote modem anddataTaker incorrect cable between remote modem and dataTaker password incorrect dataTaker was not silenced (/e /r /m /z) at end of lastsession, and so modem and dataTaker have randomlycommunicated and so may have locked up settings profile was not saved in modem during setup, themodem has since reset and is now running a defaultprofile that is unsuitable modem did not hang up properly at end of last call

Network Interface(dataTaker 500/600 series only)+ NetCOMSNetwork - a Twisted Pair of Wires (note polarity)Note: the network interface is not isolated+ NetCOMSHost Computer+ NetCOMSDatatakersPrinter+ NetCOMS+ NetCOMSSecond Host• Network is implemented tothe RS485 standard• Up to 32 dataTakers over atotal distance of 1000 metres• The network baud rate isfixed at 1200 baud• The network signalling isantiphase, balanced, at0-5 VDC• Logger Network interface istristate when quietAddressed Command#3 RA2S 1TK 3TJ LOGON

Analog to Digital Conversion

Specification Type Autocalibrating Autoranging ResolutionAnalog to Digital ConversionVCO (Voltage Controlled Oscillator)Zero voltage reference drift3 decades15 bit plus sign, 1 µVolt Sampling Period20mS (one line cycle 50 Hz)16.67ms (one line cycle 60 Hz) Accuracy>0.15%, trimmable Linearity 100Mohms selectable Common Mode Voltage CMOS Multiplexer 3.5 Volts DCRelay Multiplexer 100 Volts DC Common Mode Rejection Series Mode Rejection>100 db>35 db

Analog Input RangesInput Type Range Units Resolution Accuracy at 25 Deg CDC Voltage 25 mV 1 microV 0.11%(All Models) 250 mV 10 microV 0.11%2500 mV 100 microV 0.11%DC Voltage 7 V 250 microV 0.31%(DT505/605 only) 70 V 2.5 mV 0.31%100 V 25 mV 0.31%DC Current 0.25 mA 200 nA 0.21%2.5 mA 1 microA 0.21%25 mA 10 microA 0.21%Resistance 10 ohms 0.5 mohms 0.20%100 ohms 5 mohms 0.10%500 ohms 50 mohms 0.20%7000 ohms 500 mohms 0.30%Frequency 0.1 Hz to 0.01% 0.05%20 KHz

Analog to DigitalConversion PeriodDatataker Solution for Mains Hum RejectionMeasuredVoltageV20 mS sampling timeT

Analog Sampling SpeedThe basic analog sampling speed is determined by a channel selection time of 5 mS a channel settling time of 10 mS an analog to digital conversion time of one mains cycle,or 20 mS at 50HzThis translates to 25 analog to digital conversions per secondOther factors that affect the analog sampling speed are autocalibration returning of data in real time (baud rate) sensor linearization (thermocouples, RTDs, strain gauges) polynomials and linear spans

Analog Sampling SpeedThe magnitude of these various factors by default isDescriptionDefaultAutocalibration enabled /KAutocalibration interval P0=4 µVSettling period after channel selection P10=10mSMains frequency (internal timer)P11=50HzReturn of data in real time (baud rate) /RSensor linearization (thermocouples, YesRTDs, strain gauges)Polynomials and spansYes

Analog Sampling SpeedAnalog sampling speed can be increased by adjusting theseDescriptionDefaultDisable autocalibration /kOr increase autocalibration interval P0=100 µVDecrease settling periodP10=3mSIncrease mains frequency (internal timer) P11=1000HzLog data only/r LOGONUse simple signal types onlyV, I, FNo polynomials or spansNoPossible to increase sampling rate to 70 conversions per sec

Analog Measurement

Analog Input Multiplexing+-R100ohmSE refGroundChannel ExpansionModule connectionCMOS or RelayMultiplexersProtectionResistorsSelectorIIIVG2.500 Vreference4 voltsN/C2.5mA2504.5Vguard+refAv=1Three wirecompensationSelector Selector5 volts1KToVFC

Analog Terminal LabellingNot available as inputson the DT50Command LabelExamples:ExcitePositive InputNegative InputAnalog ReturnR#1V 1TK1+V 1+TK1-V 1-TK1#I 1#LThe # character is used asthe label for the R terminal

Differential ConnectionV XR3V3V 1321.3 mVNOISEGGround

Single Ended ConnectionGround ReferenceV XGround noisecurrentsNOISE 3+VRGGround.3+V 1340.7 mV3#V3#V 1.670 mV("NOISE" voltage)

Single Ended ConnectionExternal ReferenceV XR1+V(X)1+V -274.02 mVNOISESEGSE RefGroundThe X Channel Optionspecifies to use the SERef as common, ratherthan default to the R

DifferentialAttenuated InputDifferential InputsAttenuation Factor = (R1 + R2) / R2VR1R2R3V 3V(100)3V 1337.6 mV3V 133760 mV

Single EndedAttenuated InputSingle Ended InputsVR1R2R3+V 3+V(100)3+V 1337.6 mV3+V 133760 mV

Resistance Input - MethodBasics ofResistanceMeasurement.Current SourceKnown CurrentResistance =VoltageCurrentRV(Ohms Law)

Resistance Input - 4 Wire4 Wire MethodUnknownResistanceR1R(4W)1R 347.5 OhmsCurrent path

Resistance Input - 3 Wire3 Wire MethodUnknownResistanceLinkR2R2R 673.8 Ohms

Resistance Input - 2 Wire2 Wire MethodUnknownResistanceLinkCable CompensationResistorR8R8R 63.86 Ohms

Current Input - Internal ShuntInternal ShuntI X?5mAmax.RGGround100.0 ohms 0.1%Internal ShuntDatataker4#I4#I 5.3282 mAThe # is the label toidentify the R terminalImportant: Turn off the power supply to the instrument before makingconnections to the dataTaker. Must connect the ground terminal first.

Current Input - External ShuntExternal ShuntsI XShuntR4I(120.03)4I 18.467 mAGGroundImportant: Turn off the power supply to the instrument before makingconnections to the dataTaker. Must connect the ground terminal first.

Current Input - External ShuntUnknownCurrentsRCurrentreturnCommonSumming PointSEGSE RefGround4*I(0.05,X) 4+I(0.04,X) 4-I(0.06,X)4*I 5685.0 mA4+I -26600.0 mA4-I 14099.0 mAImportant: Turn off the power supply to the instrument before makingconnections to the dataTaker. Must connect the ground terminal first.

Current LoopsTransducerTransducerSupportCircuitryPowerAnalogSignalLoop InterfaceCurrentsourceCurrent loop(to Datataker)ISOLATIONBARRIERSensorCurrent LoopTransmitterCurrent FlowMilliampmeter24 Volt DCPowerSupply

Current Loops - Internal ShuntCurrent LoopTransmitterCurrent FlowR100.0ohm 0.1%Internal ShuntSensor24 Volt DCPowerSupplyGGround3#L 3#I3#L 50 Percent3#I 12 mAImportant: Turn off the power supply to the instrument before makingconnections to the dataTaker. Must connect the ground terminal first.

Current Loops - External ShuntOther Loops24 Volt DCPowerSupplyCurrent FlowGGroundSESE Ref6#L 6*L(X) 6+L(X) 6-L(X)6#L 8.76 Percent6*L 3.63 Percent6+L 13.37 Percent6-L 19.56 PercentCurrent LoopTransmittersBus BarRInternalShuntImportant: Turn off the power supply to the instrument before makingconnections to the dataTaker. Must connect the ground terminal first.

IC Temperature SensorsAD590 (Analog Devices)AD590AD592Bottom view of metalcan version1/R10#AD59010#AD590 23.3 Deg CLM34 and LM35 (National Semiconductors)LM34 +outLM35 -7LM347LM34 47.6 Deg CBottom viewCurrentRLM34 - 10mV/LM35 - 10mV/

IC Temperature SensorsLM34 and LM355 VDCSummingPoint10K1N91410KRGSEGroundSE Ref6+..6-LM35(X)6+LM35 47.6 Deg C6-LM35 23.9 Deg C

Thermocouples - TheoryMEASUREMENTJUNCTION0elsiusTerminals must be at thesame temperature.VCOLD JUNCTION

Thermocouples - TheoryMeasurementJunction(Type J)IronConstantanReferenceJunctionsCopperCopperMicrovoltIndicator• A thermocouple is two wires of dissimilar metals that areelectrically connected at one end (measurement junction)and thermally connected at the other end (reference junction)• A small voltage is produced when the two junctions are atdifferent temperatures• This voltage is produced by the temperature gradient alongthe wires and not by the tip

Thermocouples - Cold JunctionInternal LM35 for Cold Junction (default)MeasurementJunctionReferenceJunctionR2TK2TK 24.6 Deg C

Thermocouples - Cold JunctionExternal Cold Junction - PT100(RTD) or IC Temp. Sensor4 wire RTDRRChannel 2Channel 3RA15S 2PT385(4W,TR) 3*TJ 3+TJ 3-TJ

Resistance Temperature Detectors• Resistance Temperature Detectors or RTD's are made ofvarious metals which change resistance with temperature• Most common are Platinum RTDs or PT100s have a resistance of 100 Ohms at 0 C two calibrations in common usage 0.385 Ohm/Ohm/ C 0.3912 Ohm/Ohm/ CAustralia, EuropeNorth America• Other types include Nickel (Ni1000) and Copper (Cu)

Resistance Temperature Detectors - 4 and 3 WireRTDRCurrent path4PT385(4W,"Ambient")Ambient 27.7 Deg CLinkRTDR2PT3922PT392 23.9 Deg C

ThermistersYellowSpringsThermistorLinkR1000ohmParallelResistorWire link or optional compensationresistor equal to total lead resistance1YS01(1000)1YS01 21.5 Deg C

Bridges and Strain Gauges TheoryWheatstone Bridge+VV1R1D- D+V2D+ D-R2Strain = Change in lengthTotal lengthR4R3GNDStrain = ∆R/RGF120ohm strain gauge with GF =2,1microStrain results in ∆R of 0.00024ohm

Bridges and Strain GaugesConstant Current ExcitationCurrent Flow2.500mA4 Wire ConnectionR1BridgeR2R4R3R2BGI(4W,130)2BGI 3452 ppm

Bridges and Strain GaugesConstant Current Excitation3 Wire ConnectionR1ActivearmCurrent Flow2.500mARcR3BGI(130,I)3BGI 451 ppm

Bridges and Strain GaugesVoltage Excitation5V5V switched or an external sourceSESE RefData is the ratioof signal toexcitation voltageBridgesR cR cRGReferenceChannelGroundRSingle EndedMeasurementChannelsRA2H 3V(BR,2.0) 7*..7-BGV(N,X)7*BGV 7495 ppm7+BGV 3249 ppm7-BGV 5562 ppm

Digital Measurement

Digital Inputs andLow Speed CountersDigital Inputs1D2D3D4DG+5V10Kohm100Kohm(protection)DatatakerRA2S 2DS 2C2DS 1 State2C 638 Counts10Hz maximum count rate

High Speed Countersigh Speed Counter Inputs1C2C3C1CoutG+5V Datataker100Kohm100Kohm 10nF1HSC(R) 3HSC1HSC 2 Counts3HSC 734 Counts1KHz maximum count rate

Digital OutputsNote: A protection diode isrecommended across inductive loads+30V max100Kohmprotection+5V10KohmpullupsOutput drivinga relay (200mA max)1Dinputs2D3D4DThis terminal operatingas a voltage free input.GDatataker1DSO=1 1..2DS1DS 0 State2DS 1 State

Field Servicing

Sources of Measurement ErrorCommon Mode VoltagesDifferential Connection100 mV2 Volts2.1 Volts2 VoltsRG100 mV inputwith2 Volts of commonmode voltage plusother electrical noiseGroundNoiseRemote GroundDatataker Ground

Sources of Measurement Error Ground LoopsdataTakerSeries 1 OnlyRS232CableGround LoopDatatakerV 1 V 2AlldataTakersDatatakerSensor Cable123.45Ground LoopV 1 V 2

TEST CommandThe TEST command performs a self test of various subsystemsof the loggerCommandsTESTTESTRTESTnTESTnR- execute the full test once- repeatedly execute the full test- execute line n of the test once- repeatedly execute line n of the testCan be used in the field to help identify some faultsYou may be asked to run TEST command if you call in with ameasurement problem

TEST CommandReturned DataDatataker 524 Ver 5.00Vos (mV) -0.024Vfo (V) 7.492Fc (kHz) 12.774CMRR(db) 103.9Vos3(mV) -0.026Tos 1.0048Ios (nA) 0Ibia(nA) 7Ibat(mA) 112.7Vbat (V) 6.8Vos* (µV) -71Vos+ (µV) 5Vos- (µV) 7VosR (µV) -69Vosd(µV) 4Ics1(mA) 2.5008Ics2(µA) 249.89PASSLine n01234567891011121314151617DescriptionConfig & Firmware versionInput offset (Zero'd out)Input voltage for VCO Freq=0VCO frequency at zero voltsCommon mode rejection ratio3 wire offset (Zeroed out)Termination offsetDifferential input offset currentDifferential input bias currentBattery current(- for discharge)Battery voltage (about 5.4 to 13 V)* terminal offset voltage+ terminal offset voltage- terminal offset voltageR terminal offset voltageDifferential offset voltagecurrent source 1current source 2Test Pass or Fail

TEST CommandTESTDatataker 524 Ver 4.01Vos (mV) 0.021Vfo (V) 6.962Fc (kHz) 12.584CMRR(db) 108.1Vos3(mV) 0.290Tos 1.0023Ios (nA) 0Ibia(nA) 7Ibat(mA) 5.2Vbat (V) 6.8Vos*(uV) -21Vos+(uV) 14Vos-(uV) 8VosR(uV) 14Vosd(uV) 14Ics1(mA) 2.5189Ics2(uA) 250.40PASS

TEST CommandTest data that is out of range is flagged with a “Fail” messageFor exampleVos+(uV) 23.3 FailFails can indicate type of problemsA ‘terminal offset voltage fail’ is due to multiplexer(s) failure,or common mode voltage over-range, and can often berepaired in the field by replacing multiplexers (not DT505/605)Other failures usually require some level of factory service

Internal ChannelsVarious internal calibration channels can also be used toidentify failuresInternal ChannelSpecificationLogger Temperature1%LM35Expander Module (n) Temperature n:1%LM35Electrical zero at multiplexer 2%VPrecision 100.0 Ohm 0.1% 2%RPrecision 4700 Ohm 0.1% 3%R (DTxx5 models)Battery Voltage0%V(M17:156,101)Battery Current0%I(M17:188,-0.22)

Field ServicingMost common problems causing errors in measurement are common mode voltages ground loops via sensors and/or comms cable nearby electrical interference multiplexer failureThese errors are often associated with only some of thesensor set, however effects all measurementsThese types of problems can be identified by disconnectingall sensors, then add sensors back one at a time whilelooking for a TEST failure

Field ServicingIf you have bad measurements Run TEST and look for any failures If no failures then sensor(s) could be faulty If there are any ‘terminal offset voltage fails’ then removeall sensors and run TEST again If there are failures then replace multiplexer chips If there are still failures then return logger for service Add sensors back one at a time, running TEST betweeneach sensor If there are any ‘terminal offset voltage fails’ this identifiessensor(s) causing problems. Look for offset voltages andground loops associated with the sensor and correct

Field ServicingIf you still have bad measurements, then there could beground loops via the comms cable (Series 1 only) Run a shcedule reading all sensors, and log data Disconnect comms cable and collect some data intomemory Reconnect comms cable, Halt scanning and unload datafrom memory If the data is good while computer was disconnected, thenthere is a ground loop problem via comms cable Isolate comms interface

Field ServicingIf you have noisy measurements This will most likely be due to electrical interference This more likely to affect sensors with small signal levelssuch as thermocouples, strain gauges, etc Can also get noisy readings if thermocouple tip(s) areelectrically in contact with structures allowing direct pickupof small currents. Insulate all thermocouple tips. Look for nearby installations that are electrically noisy Protect sensor cabling with shielding

Notes

Notes