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Data Acquisition Module USB

1. Start Trigger Level Y Channel ANTH v Mode above z Level 5 000254 Stop Trigger Level Date Time Time Span Scan Count Figure 4 15 Stop Trigger Options Trigger Types Manual Acquisition is manually started stopped Level Set trigger to stop start acquisition when the input level is either above or below a certain threshold Date Time Set trigger to stop start acquisition at a certain date and time as per the PC s clock Time Span Set trigger to stop acquisition after a certain elapsed time Scan Count Set trigger to stop acquisition after a certain number of scans have been acquired Software V For all Start Trigger types the device must be armed by pushing the Start Button on the main window Data storage and display will not begin until the device triggers Data Tab B Device Configuration A700haWK ile x Channels Triggers Data IV Save data to file bettings Administrator D esktop A700haWK bin Browse Save Behavior Auto overwrite v Figure 4 16 Data Tab To save data to a file on the PC select the Data tab and choose a filename This data can be saved in Binary or Delimited csv format Binary format is faster and is recommended for slower PCs Binary format also creates files that are about 50 smaller than Delimited files Binary files can be converted to csv format later by selecting Tools gt Export Data File e Delimited format can use either co
2. NOTES USA WARRANTY DISCLAIMER OMEGA ENGINEERING INC warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase OMEGA s WARRANTY adds an additional one 1 month grace period to the normal one 1 year product warranty to cover handling and shipping time This ensures that OMEGA s customers receive maximum coverage on each product If the unit malfunctions it must be returned to the factory for evaluation OMEGA s Customer Service Department will issue an Authorized Return AR number immediately upon phone or written request Upon examination by OMEGA if the unit is found to be defective it will be repaired or replaced at no charge OMEGA s WARRANTY does not apply to defects resulting from any action of the purchaser including but not limited to mishandling improper interfacing operation outside of design limits improper repair or unauthorized modification This WARRANTY is VOID if the unit shows evidence of having been tampered with or shows evidence of having been damaged as a result of excessive corrosion or current heat moisture or vibration improper specification misapplication misuse or other operating conditions outside of OMEGA s control Components in which wear is not warranted include but are not limited to contact points fuses and triacs OMEGA is pleased to offer suggestions on the use of its various products However OMEGA neither assumes respons
3. YEAR C WARRANTY Shop online at omega com e mail info omega com Exe ome eA For latest product manuals dg www omegamanual info ATA MITES Ic NN OM DAQ USB 2401 Multiple Channel USB Data Acquisition Module X OMEGA omega com info omega com Servicing North America U S A Omega Engineering Inc One Omega Drive P O Box 4047 Stamford CT 06907 0047 USA Toll Free 1 800 826 6342 USA amp Canada only Customer Service 1 800 622 2378 USA amp Canada only Engineering Service 1 800 872 9436 USA amp Canada only Tel 203 359 1660 Fax 203 359 7700 e mail info omega com For Other Locations Visit omega com worldwide The information contained in this document is believed to be correct but OMEGA accepts no liability for any errors it contains and reserves the right to alter specifications without notice WARNING These products are not designed for use in and should not be used for human applications OM DAQ USB 2400 TABLE OF Multiple Channel USB Data Acquisition Module CONTENTS Page Section 1 E Introduction 0000000000000000000000000000000000000000000000000000000000000000000000 1 1 LI PENE vrede 1 1 1 2 Safety Warnings and IEC Symbols assai trt utbsieiuken iare oues 1 2 15 Statement on CE M SERIE cis uber cuidado on ieviesies GO ci rU 1 2 1 4 General Description and System Components a 1 2 Section 2 Ha
4. RH non condensing exclusive of noise 0 015 of reading 004 of range In very slow mode 10uV exclusive of noise 0 05 of reading 0 01 of range In very slow mode 50uV exclusive of noise 40 to 85 C 40 to 185 F 0 5 Ibs 0 23 kg 107 W x 128 L x 39mm H 4 2 x 5 1 x 1 5 Software programmable On A Per channel Basis 10 to 10V 5 to 5V 2 5 to 2 5V 2 to 2V 1 to V 500 to 500 mV 250 to 250 mV 125 to 125 mV 75 to 75 mV 30 to 30 mV Thermocouple Input Range Cold Junction Compensation Accuracy Input Voltage Range Relative To Analog Common COM Input Resistance Absolute Maximum Input Voltage Warm up USB Device Type Device Compatibility Power Supply External Power Source DIN Rail Mounted For Rack Application Open Thermocouple Detect Limitations of the Total Recording Memory Size MCU Specifications V Type J 18 to 1200 C 0 to 2192 F Type K 129 to 1372 C 200 to 2502 F Type T 101 to 400 C 150 to 752 F Type E 184 to 1000 C 300 to 1832 F Type R 204 to 1768 C 400 to 3214 F Type S 204 to 1768 C 400 to 3214 F Type B 538 to 1820 C 1000 to 3308 F Type N 129 to 1300 C 200 to 2372 F DAS 1 0 C 10 to 10 Vdc 1MQ single ended 2MQ differential 5 20 V maximum relative to analog common 1 hour to rated specifications USB 2 0 full speed USB 1 1 USB 2 0 From USB Port or 9 Vdc adaptor
5. Scan Rate SR Range 0 153Hz lt SR lt 1Hz 60 Hz rejection Scan Rate SR Range 1Hz SR lt 1 667Hz OMB DAQ USB 2401 Series Block Diagram Power LED Isolation Barrier Power Supply o Isolated Power Jack O JE Power Supply o o Local Power O USB nn Pa I Jack GTA USB Controller lt H Activity LED DE mmi E MCU 32Bit Digital Isolators CJC A 4 iQ Analog Inputs Gain HEV x2 1 8 Excitation voltage 2 __ SE TIC MUX DI PGIA N 4 Analog Inputs Gain x1 2 4 8 16 32 64 tion V 2 24 Bit Excitation voltage i Se x 1MO 1MO MUX PGA A D CJC 4 Analog Inputs Gain nv x2 1 8 Excitation voltage ce MUX SE PGIA 4 Analog Inputs 12v output Excitation voltage NA 1MO 1MO Figure 4 25 OM DAQ USB 2400 Block Diagram 4 5 Optical Isolation Your DAQ unit is optically isolated from its host PC by up to 500 Vdc This means that an inadvertent application of such voltage to the DAQ unit will not affect the PC In addition to isolation the device maintains all sensitive acquisition related circuitry external to the PC T
6. 1 Each analog input channel has the following user specified measurement parameters e Signal type volts or thermocouple type J K T E R S B or N Full scale voltage from 10 to 10 Vdc with programmable ranges as indicated on page 8 1 Resolution sample period from 22 5 bit RMS at 0 153 samples sec to 17 bit RMS at 50 samples sec or greater o These rates were obtained with a 16 channel scan 4 8 Analog Input Configuration The OM DAQ USB 2401 includes 16 analog signal inputs which may be used as 16 single ended inputs 8 differential inputs or as a combination of single ended and differential inputs with up to 16 connections Single ended inputs are used with signals that share the same common low COM such as multiple batteries which have their negative sides connected in common Differential inputs are required when signals do not share the same common low such as in the typical use of thermocouples g Software In DAQ applications thermocouples should not be connected single ended Doing so can result in noise and false readings This is especially true when acquiring other high amplitude signals in conjunction with thermocouple signals that are connected single ended The DAQ units include built in cold junction compensation CJC which is automatically invoked when you select TC measurements The OM DAQ USB 2401 automatically converts acquired voltage readings into compensated linearized
7. 2401 devices which are currently connected to the computer through the USB Configuration Same function as Configuration button al Accesses the device Configuration window to configure Channels settings Triggers settings and Data settings Start Acquisition Same function as Start button gt Initiates data acquisition for the highlighted device Even if a Start Trigger is set this must be selected to Arm the device Stop Acquisition Same function as Stop button al Stops data acquisition for the highlighted device If a Stop Trigger is set this will cancel the trigger Sofrware 8 Omega DAQ Central amp 100ekLS DAQ2401DEMO l Figure 4 7 Tools Menu Export Data File To convert data file from binary file to csv file E lomega DAQ Central S1O0eKLS Figure 4 8 Help Menu Check for Updates To check for the latest Omega DAQ Central software update information through the Internet connection About To view software version 4 7 v Software 4 8 Section 4 3 2 Device Configuration The Device Configuration window contains the Channel Triggers and Data tabs Details for these tabs are below When finished making changes press OK to confirm the changes or Cancel to abandon the changes Device Configuration A700haWK Differential xd zi My 3rd Channel gt z am VO el Shales mar zl sll Bl El zi zl zi zi My 2nd Channel V Differe
8. 3 4 Connection to USB powered Hub 3 5 Connection to Self powered Hub and to USB powered Hub sucer repr 3 6 OM DAQ USB 2401 Wall Mounting 3 7 OM DAQ USB 2401 Wall Mounting DIMENSIONS t NEN 3 7 OM DAQ USB 2401 Rail Mounting 3 8 Welcome Screen snein eon el cir s ardeo 4 2 Select Install Screen iue tet irt tn te oce 4 2 Confirm Installation Sereen sore renes 4 3 Main Control WINdOW entrate pian 4 4 Toolbar Dub Pls usce remit eE 4 5 File Menu e 9 4 6 Device Men ye tenseso 4 6 Tools MENU sisstin erissa iera iaiia 4 7 Help Menu seoemunmsesdemaininenekurji 4 7 Configuration Mode Channels Tab Screen 4 8 Scan ODBDDS som 4 9 Unit OOS es nie t eb EH AFD EQUI AMENS 4 9 Automatic CaliDEaldun s oeste rir erba 4 9 Hy Ga eee eter e tune Ei 4 10 Start Trigg r Opti ns iiecscuri HH URS 4 10 SLOP Trigger ODBODS Janssen 4 10 Data TaD C 4 11 Data Save Behavior Option suesmnevivmsriisineine 4 11 Man Window Screen niesi es ieser 4 12 CAUSE STEEN reie erior a R E 4 12 Bs SEN RN M 4 12 Digital SCPC ON iausdskostencen Son FLUE OA E RHONE 4 12 Table Screen M 4 12 Waveform DOPO sisenes Dice SRI Rui RES 4 13 Sample Options SCHOEN vierrsnndeneernunn 4 13 OM DAQ USB 2400 Multiple Channel USB Data Acquisition Module List of Figures Section Figure DWescripuon sisasdunincnmunwnnannaaensinnnass Page 4 25 OM DAQ USB 2
9. 44 Power Line Rejection uuu n eigen d pet ont bora Us 4 14 45 Optical Isolation EE PSR MV RE QUAD UE rp Re 4 14 4 6 DMT uren 4 14 27 Input Ranges s mmen va een 4 15 4 8 Analog Input Cone ral Duo cs battu arceat cobre beca rele 4 15 4 9 Measurement Duration Scan Time and Resolution 4 16 4 10 Aut matie Calibtatl D EEE ER ER 4 17 4 11 Thermocouple Measurements sunnoeennesievti pund 4 18 Section 5 Signal Management 5 1 5 1 Channel Control and Expansion sijescxsssees crasndsaysaisgcastestoaventnammssiniens 5 1 5 2 Scan Time and Resolution esee 5 1 52 1 Scan TIME u u On IUE OH 5 1 5 2 2 Resolution Effective Number of Bits ENOB RMS 5 5 9 Under Sampling and Aliasing sssini otse epe Eod 5 2 CONTENTS Multiple Channel USB Data Acquisition Module zm Wir e M 5 4 5 5 Signal Modes siistisi ans erede aided iae ue eder eres eia nii y 5 4 9 6 Systemi NO18S6_ a ssssissuksisasapypasqa P 5 6 ER dieu reni EErEE Un CN EDEN DE GE 5 6 50 Analog Filtering ME 5 6 5 9 Input atid Source Impedarice u ssyessthayuannctaciasiadenssisaenbonaeciidieiieaeal 5 7 9 10 Crosstalk Fe 5 7 9 1 Service and Calibration 2i die csi Ee i cuu Quia enki t RU REMO rela E Y 7 1 Section 6 B CE Conformity 000000000000000000000000000000000000000000000000000000000000
10. 6 OM DAQ USB 2401 Wall Mounting le 146 6 00 133 5 50 MOUNTING HOLE DISTANCE lt N WON THIN WH WA OM TIHIATTIH e PA To EIER e PAPA e P 4Te E ET EIL E ofsjo vivjo lviv oJa 9 v v 9 V V ST Gn V QUELLE N 2 PLACES MNA 0 125 OM DAQ USB 2400 SERIES 107 USB DATA ACQUISITION SYSTEM 4 20 6 A 2 PLACES vo 0 25 V Y Figure 3 7 OM DAQ USB 2401 Wall Mounting Dimensions 3 7 g Hardware Setup 3 5 2 OM DAQ USB 2401 DIN Rail Mounting In order to mount the OM DAQ USB 2401 to a DIN Rail you will need to 1 Attach the DIN rail plastic adaptors to the mounting brackets using the four shorter screws 2 Remove the rear screws from the OM DAQ USB 2401 3 Align the mounting brackets with the rear holes on the DAQ unit make sure that the ears are facing inwards like in the figure below Use the longer screws to reconnect the mounting brackets to the body of the enclosure in the same direction as the screws that were removed from the DAQ unit Attach the DAQ unit to the DIN rail using the plastic adaptors attached to the mounting brackets X VS NG N D S 9 222 SN X Sy Figure 3 7 OM DAQ USB 2401 Rail Mounting Sofrware V Section 4 Sofrware 4 1 Getting Started The following program files are included on the Omega DAQ Central User Software CD supplied with your data acqu
11. Cartridge amp Strip Heaters IA Immersion amp Band Heaters L7 Flexible Heaters IA Laboratory Heaters ENVIRONMENTAL MONITORING AND CONTROL A Metering amp Control Instrumentation A Refractometers LY Pumps amp Tubing A Air Soil amp Water Monitors IA Industrial Water amp Wastewater Treatment IA pH Conductivity amp Dissolved Oxygen Instruments M5025 0514
12. Rate vs Resolution ENOB RMS Notes 1 Scan Rate 1 Scan Time 2 Each channel can have independent measurement duration and resolution 3 The scan rates and resolutions shown were obtained with a 16 channel scan and with continuous self calibration 4 When measuring TC input the CJC measurements will be treated as a channel 5 ENOB Effective Number of Bits 5 3 Under Sampling and Aliasing When you select the Scan Time you also determine the scan rate and resolution for the applicable channel As shown in the previous table scan rates range from 0 0002778 scans sec up to 1000 scans sec and corresponding resolution ranges from 22 5 to 17 bit for the DAQ s analog input applications When measuring highly variable input signals as opposed to relatively steady input signals the variable signals will require more scans sec to obtain a realistic signal representation When too few samples are taken the term under sampling is often used Under sampling tends to lower the signal s graphed amplitude This is also known as aliasing In such cases the inadequate number of samples results in a flattening of the signal Gross under sampling can even result in a relatively flat line even though the actual signal is a waveform For best results the sample rate scan rate should be at least 10 times the measurement frequency If possible it is recommended that you set the scan rate to 20 times the frequency of the input signa
13. Required when used with a bus powered hub Optional Automatically enable when a channel is configured for a thermocouple sensor 1 G or 500M in PC 32 bit w All temperature specifications assume unit is held in relatively still air environment 9 UNIV AC 100 240 the external power supply is a Universal Power Adaptor It is a 100 240 VAC to 9 Vdc output adaptor 9 2 g Specifications Table 9 1 Thermocouple Accuracy C for OM DAQ USB 2401 TC Type Temp Typical C Slow 18 1 3 J 0 1 1 1200 0 9 129 1 8 K 0 1 4 1372 1 3 101 1 6 T 0 1 4 400 1 184 1 2 E 0 0 9 1000 0 7 204 5 2 R 700 4 1768 3 9 204 5 S 700 5 2 1768 4 6 B 538 79 1820 4 8 129 2 6 N 0 2 1300 1 4 _ Mn Thermocouple accuracy excludes cold junction compensqtion error 9 3 Fast 3 8 25 3 9 3 7 4 5 2 9 3 4 2 6 1 9 14 8 13 1 11 16 14 7 12 8 13 7 13 7 7 3 5 9 Approvals and Regulatory Compliance V 10 1 International Usage amp CE Marking The OM DAQ USB 2401 multiple channel USB data acquisition module is CE marked and certified for use in several European countries Please contact OMEGA for information on International Regulatory Compliance for each country It is your the user s responsibility to insure that these products are operated within the guidelines here in this manual and in conformance with all local or national regulations and laws NOTES NOTES
14. a 10 V range 5 6 System Noise Laboratory and industrial environments often have multiple sources of electrical noise An AC power line is a source of 50 60 Hz noise Heavy equipment air conditioners elevators pumps etc can be a source of noise particularly when turned on and off Local radio stations are a source of high frequency noise and computers and other electronic equipment can create noise in a multitude of frequency ranges Thus an absolute noise free environment for data acquisition is not realistic Fortunately noise reduction techniques such as averaging filtering differential voltage measurement and shielding are available to reduce noise to an acceptable level 5 7 Averaging Certain acquisition programs apply averaging after several samples have been collected Depending on the nature of the noise averaging can reduce noise by the square root of the number of averaged samples Although averaging can be effective it suffers from several drawbacks Noise in measurements only decreases as the square root of the number of measurements reducing RMS noise significantly may require many samples Thus averaging is suited to low speed applications that can provide many samples Only random noise is reduced or eliminated by averaging Averaging does not reduce or eliminate periodic signals 5 8 Analog Filtering A filter is an analog circuit element that attenuates an incoming signal according to its freq
15. temperature readings This DAQ system can make thermocouple and volts measurements concurrently OM DAQ USB 2401 TERMINAL BLOCK PARTIAL Figure 4 26 OM DAQ USB 2401 Single Ended and Differential Connections to Analog Input Channels Diagram Figure Notes V1 and V2 are single ended inputs V3 is a thermocouple and is a differential input 4 9 Measurement Duration Scan Time and Resolution In relation to sampling analog input the terms measurement duration sample rate and resolution have the following meanings Measurement duration per channel the amount of time used for sampling a channel s input signal The measurement durations for the OM DAQ USB 2401 s analog channels range from very slow 400 milliseconds for one measurement duration to very fast 1 millisecond for one measurement duration Scan Time per scan The amount of time used for scanning sampling all selected channels input signal For the OM DAQ USB 2401 the scan rates range from very slow 1 hour per scan to very fast 1 milliseconds per scan Software V Resolution Effective Number of Bits ENOB RMS The number of reliable data bits that exist for a signal s measurement The greater the resolution the more detailed the reading For example with an increased resolution a reading of 5 12 V could become 5 11896 V The DAQ actually provides for 24 bits of data information however the accuracy of the least sig
16. 00000000 6 1 6 1 OM DAQ USB 2401 Design for CE Conformity 6 1 Section 7 Troubleshooting 771 7 1 Basic More EE aussi uuu 7 1 7 2 Symptomsand Soluti nS uiuos eie retain eere RAE IIR ERROR MESE REED 7 1 Section 8 Service and Calibration 000000000000000000000000000000000000000000000000000000 8 1 8 1 Service and Calibration eeeosooovnvvnnoenesnnnnennsnnnesnnnnennssnsennnnnnnnnnnsssnunneneene 8 1 Section 9 d Specifications 000000000000000000000000000000000000000000000000000000000000000000000 9 1 Section 10 Approvals and Regulatory Compliance 10 1 10 1 International Usage and CE Marking retener 10 1 List of Figures Section Section 1 Section 3 Section 4 Multiple Channel USB Data Acquisition Module Figure 1 1 1 2 3 1 3 3 3 4 3 5 3 6 3 7 3 8 4 1 4 2 4 3 4 4 Table 4 1 4 5 4 6 4 7 4 8 4 9 4 10 4 11 4 12 4 13 4 14 4 15 4 16 4 17 4 18 4 19 4 20 4 21 4 22 4 23 4 24 OM DAQ USB 2400 Des ripti n aider prie tre FOPEDUAME EDD EH DDG I QE KS Page TEC Symbols usu biruio itii be Dd Elke 1 2 System COMPONENTS uu uspussassusdaqhuyshakisspashasas 1 3 OM DAQ USB 2401 Hardware and Dimensions 3 1 Connection of an OM DAQ USB 2401 System toa Computer USB Port ccrto tart rre 3 3 Direct Connection to Computer USB Port
17. 400 Block Diagram 4 14 4 26 OM DAQ USB 2401 Single ended and Differential Conections to Analog Input Channels Diagram 4 16 4 27 Calibration Scan Arrangement 4 17 Section 5 Table 5 1 Scan Rate vs Resolution ENOB RMS 5 2 5 1 Examples of Under Sampling torte 5 3 5 2 Trigger Source Diagram c aaassanasa 5 4 5 3 Noise Reduction in Differential Mode 5 5 5 4 Example of Floating Differential Circuit 5 5 5 5 Analog to Digital Converter oan arra 5 7 Section 6 6 1 OM DAQ USB 2401 With Ferrite Cores Installed 6 1 6 2 Pee C OY TEN 6 2 Section 9 Table 9 1 Thermocouple Accuracy C for OM DAQ U B 2400 hunnene 9 1 Introduction V Section 1 Introduction Please read this manual completely before installing and operating your Omega data acquisition system It s important to read and follow all notes cautions warnings and safety precautions before operating this device Device refers to your data acquisition unit 1 1 Precautions This device is not designed for use in any medical or nuclear applications Do not operate this device in flammable or explosive environments Never operate with a power source other than the one recommended in this manual or listed on product labels This device has been designed for dry moisture free indoor applications only Do not operate this device outside of the recommended us
18. EGA harmless from any liability or damage whatsoever arising out of the use of the Product s in such a manner RETURN REOUESTS INQUIRIES Direct all warranty and repair requests inquiries to the OMEGA Customer Service Department BEFORE RETURNING ANY PRODUCT S TO OMEGA PURCHASER MUST OBTAIN AN AUTHORIZED RETURN AR NUMBER FROM OMEGA S CUSTOMER SERVICE DEPARTMENT IN ORDER TO AVOID PROCESSING DELAYS The assigned AR number should then be marked on the outside of the return package and on any correspondence The purchaser is responsible for shipping charges freight insurance and proper packaging to prevent breakage in transit FOR WARRANTY RETURNS please have the FOR NON WARRANTY REPAIRS consult OMEGA following information available BEFORE for current repair charges Have the following contacting OMEGA information available BEFORE contacting OMEGA 1 Purchase Order number under which the product 1 Purchase Order number to cover the COST was PURCHASED of the repair 2 Model and serial number of the product under 2 Model and serial number of the product and warranty and 3 Repair instructions and or specific problems 3 Repair instructions and or specific problems relative to the product relative to the product OMEGA s policy is to make running changes not model changes whenever an improvement is possible This affords our customers the latest in technology and engineering OMEGA is a registered trademark of OMEGA ENG
19. ER ADAPTER HUB DU gt POWER USB 4 ADAPTER 22 USB UB WP Figure 3 5 Connections to Self Powered Hub and to USB Powered Hub ey USB port locations vary from PC to PC 3 5 OM DAQ USB 2401 Mounting The OM DAQ USB 2401 mounting kit contains the following accessories e 2 mounting brackets to be used for either wall or DIN rail 4 long screws to be used for either wall or DIN rail 4 short screws to be used for the DIN rail 2DIN rail plastic adaptors Hardware Setup V 3 5 1 OM DAQ USB 2401 Wall Mounting In order to mount the OM DAQ USB 2401 to the wall you will need to 1 2 Remove the rear screws from the OM DAQ USB 2401 Align the mounting brackets with the rear holes on the DAQ unit make sure that the ears are facing outwards like in the figure below Use the longer screws to reconnect the mounting brackets to the body of the enclosure in the same direction as the screws that were removed from the DAQ unit Drill 2 holes for 4 screws 5 50 apart Tip Hold the DAQ unit with mounting brackets attached up against the wall use the holes as a guide to mark where you will drill holes in the wall Install the two screws into the wall Mount the DAQ unit on the wall by passing the screw head through the larger mounting bracket holes and then sliding it down Figure 3
20. INEERING INC Copyright 2014 OMEGA ENGINEERING INC All rights reserved This document may not be copied photocopied reproduced translated or reduced to any electronic medium or machine readable form in whole or in part without the prior written consent of OMEGA ENGINEERING INC Where Do I Find Everything I Need for Process Measurement and Control OMEGA Of Course Shop online at omega com TEMPERATURE IA Thermocouple RTD amp Thermistor Probes Connectors Panels amp Assemblies IA Wire Thermocouple RTD amp Thermistor A Calibrators amp Ice Point References 4 Recorders Controllers amp Process Monitors IA Infrared Pyrometers PRESSURE STRAIN AND FORCE lA Transducers amp Strain Gages lA Load Cells amp Pressure Gages A Displacement Transducers 4 Instrumentation amp Accessories FLOW LEVEL A Rotameters Gas Mass Flowmeters amp Flow Computers Z Air Velocity Indicators IA Turbine Paddlewheel Systems IA Totalizers amp Batch Controllers pH CONDUCTIVITY IA pH Electrodes Testers amp Accessories IA Benchtop Laboratory Meters A Controllers Calibrators Simulators amp Pumps IA Industrial pH amp Conductivity Equipment DATA ACQUISITION IA Data Acquisition amp Engineering Software IA Communications Based Acquisition Systems L7 Plug in Cards for Apple IBM amp Compatibles IA Data Logging Systems 4 Recorders Printers amp Plotters HEATERS IA Heating Cable LY
21. Stops data acquisition for the highlighted device If a Stop Trigger is set this will cancel the trigger Accesses the Device Configuration window for the selected device The Device Configuration window is used to set up all device options including channels sample rate triggers and data output file Opens a Gauges window Displays measurements in analog meter format Opens a Bars window Displays measurements in a bar graph format Opens a Digital meter window Displays measurements in a digital meter format Opens a Table window Displays measurements in a table format Opens a Waveform window Displays the measurements in a scrolling chart Displays The available connected DAQ devices DAQ2401DEMO Demo simulation device for testing software features without hardware LEDs Will flash green during the data acquisition Table 4 1 Toolbar Buttons 4 5 v Software 4 3 1 Main Control Window Pull Down Operations Below are the operations that are available in the Pull Down Menus of the DAQ Central Main Control Window Efl Omega DAQ Central Figure 4 5 File Menu Open Contiguration Opens Device Configuration settings trom a saved file Save Configuration As Saves current Device Configuration settings to a new file name These settings files contain all of the data that is found in the Device Configuration window Figure 4 6 Device Menu Detect Devices Detects available OM DAQ USB
22. e Service and Calibration V Section 8 Service amp Calibration Your Omega DAQ components have been built and factory calibrated to meet or exceed the specifications listed here in this manual The following section provides information on how to have your device serviced 8 1 Service amp Calibration If any of your DAQ system components require service or calibration please call our Customer Service Department at 1 800 622 2378 or 203 359 1660 They will assist you in arranging the return and service of your device We can also be reached on the Internet at www omega com e mail cservice omega com g Specifications Section 9 Specifications 500V from PC External Excitation Output Voltage 12v DC Regulated General Isolation Power Requirements Thermocouple Types Cold Junction Compensation Accuracy Isolation Channel Capacities Environmental Operating Temperature Analog Input Accuracy Differential Input Single end Input Storage Temperature Weight Dimensions Input Voltage Range Differential Single ended Maximum total current output 67mA Powered from USB port max 500 mA or from external 7 5 to 12 Vdc 1 0 A recommended J K T E R S B N 1 0 C 500 Vdc from PC common Volts Inputs 8 DE or 16 SE Thermocouple Inputs 8 DE DE Differential Mode SE Single ended mode 0 to 50 C 0 to 122 F 95 RH non condensing 0 to 50 C 32 to 122 F 0 to 95
23. e outlined in this manual Never use your data acquisition unit as a portable device Your unit has been designed to be operated in a permanent installation only _ ee There ore no user serviceoble ports inside your device Attempting to repair or service your unit may void your warranty A The discharge of static electricity can damage some electronic components Semiconductor devices are especially susceptible to ESD damage You should always handle components carefully and you should never touch connector pins or circuit components unless you are following ESD guidelines in an appropriate ESD controlled area Such guidelines include the use of properly grounded mats and wrist straps ESD bags and cartons and related procedures _ Never remove a USB cable from an active OM DAQ USB 2401 unit while an acquisition is in progress An active unit is any unit that is currently open and has channels configured for scanned input Such disconnection may require you to exit and then re launch Omega DAQ Central after the USB cable has been connected 1 1 Wy Introduction When using OM DAQ USB 2401 unit to acquire data computer energy save modes can cause false data readings Prior to using the unit ensure your computer s energy save mode is disabled If needed consult your PC user s manual to disable energy save power suspension modes 1 2 Safety Warnings and IEC Symbols This device is marked with internati
24. el resulting in interference or signal distortion The impact of source impedance and stray capacitance can be estimated by using the following equation T RC Where T is the time constant R is the source impedance and C is the stray capacitance High source transducer impedance can be a problem in multiplexed A D systems When using more than 1 channel the channel input signals are multiplexed into the A D The multiplexer samples each signal and then switches to the next input signal A high impedance input interacts with the multiplexer s stray capacitance and causes crosstalk and inaccuracies in the A D sample A solution to high source impedance in relation to multiplexers involves the use of buffers The term buffer has several meanings but in this case buffer refers to an operational amplifier having high input impedance but very low output impedance Placing such a buffer on each channel between the transducer and the multiplexer prevents the multiplexer s stray capacitance from combining with the high input impedance This use of a buffer also stops transient signals from propagating backwards from the multiplexer to the transducer CE Conformity g Section 6 CE Conformity 6 1 OM DAQ USB 2401 Design for CE Conformity The OM DAQ USB 2401 has been designed to meet requirements as outlined in European Community EMC Directive EN61326 Three ferrite cores are included in the OM DAQ USB 2401 package When powering the
25. er cable is plugged in Signal Check signal lines and connections Connectors must be free of corrosion Signal lines should be undamaged and free of sharp bends and twists Signal paths should avoid potential sources of noise high voltage and electromagnetic interference Device Selection Make sure the serial number selected in the software matches the serial number of your device Each data display will show the serial number or Nickname if assigned of the device it is currently displaying DAQ2401DEMOC is a software demo device which outputs a sine wave Software Updates A software update may be available In DAQ Central choose Check For Updates from the Help Menu on an Internet connected PC 7 2 Symptoms and Solutions USB drivers are not found or hardware installation fails This can happen if the device is plugged into the computer s USB port before software installation is complete The program C Program Files Omega V DAQ Central USB Drivers CDM20814 Setup exe can be run to reinstall the USB drivers All non critical USB devices should be unplugged while this program runs including all DAQ devices The 20814 portion of this filename may be different and the DAQ Central USB Drivers directory may be in a different location if an alternate directory was chosen during installation Data does not appear or data does not make sense See Device Selection under Basic Checklist Stop the acqui
26. from 30 mV to 10V full scale The compact modular packaging ensures ease of use in a variety of applications Units can be DIN rail or wall mounted with the included hardware or easily operated on a bench All analog input channels can be measured sequentially at about 1 ms per channel A total of 1000 samples per second can be taken divided across all active channels Introduction At highest scan rate 1000 samples sec 1 with one channel on 5 with all channels on The main items you will be using in your data acquisition system are the OM DAQ USB 2401 unit its USB cable and power adaptor POWER ADAPTER OPTIONAL OM DAQ USB 2401 MODULE c U S 00 PC WITH USB CONNECTION NOT INCLUDED Figure 1 2 System Components 1 3 Hardware g Section 2 Hardware It is important that you read this manual completely and follow all safety precautions before operating this instrument 2 1 Package Inspection Remove the packing list and verify that you have received all your equipment If you have any questions about the shipment please call our Customer Service Department at 1 800 622 2378 or 203 359 1660 We can also be reached on the Internet at omega com e mail cservice omega com When you receive the shipment inspect the container and equipment for any signs of damage Note any evidence of rough handling in transit I
27. his physical isolation of circuitry from the PC results in less noise and more accurate measurements 4 6 A D Conversion OM DAQ USB 2401 uses an extremely low noise 24 bit analog to digital A D converters They provide complete high resolution measurement solutions for 4 14 the most demanding applications Software V The converter is comprised of a 4th order delta sigma AX analog to digital A D converter modulator followed by a programmable digital filter A flexible input multiplexer handles differential or single ended signals the programmable filter allows the user to optimize between a resolution of up to 23 bits noise free Examples of scan sequences with various channel resolutions and calibration arrangements appear in Table 5 1 on page 5 2 4 7 Input Ranges You can individually select the input range for each channel For example one channel could be used for volts and another for temperature Omega s OM DAQ USB 2401 automatically assigns the appropriate units depending on two factors The selected range and Measurement unit preferences Measurement unit preferences can be modified from the Omega DAQ Central Channels tag of the Configuration window Chapter 4 provides more detailed information The maximum voltage input range full scale is 10 to 10 Vdc The lowest programmable voltage input range is 30mV to 30 mV A complete list of the OM DAQ USB 2401 s programmable ranges appears on page 8
28. ibility for any omissions or errors nor assumes liability for any damages that result from the use of its products in accordance with information provided by OMEGA either verbal or written OMEGA warrants only that the parts manufactured by the company will be as specified and free of defects OMEGA MAKES NO OTHER WARRANTIES OR REPRESENTATIONS OF ANY KIND WHATSOEVER EXPRESSED OR IMPLIED EXCEPT THAT OF TITLE AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED LIMITATION OF LIABILITY The remedies of purchaser set forth herein are exclusive and the total liability of OMEGA with respect to this order whether based on contract warranty negligence indemnification strict liability or otherwise shall not exceed the purchase price of the component upon which liability is based In no event shall OMEGA be liable for consequential incidental or special damages CONDITIONS Equipment sold by OMEGA is not intended to be used nor shall it be used 1 as a Basic Component under 10 CFR 21 NRC used in or with any nuclear installation or activity or 2 in medical applications or used on humans Should any Product s be used in or with any nuclear installation or activity medical application used on humans or misused in any way OMEGA assumes no responsibility as set forth in our basic WARRANTY DISCLAIMER language and additionally purchaser will indemnify OMEGA and hold OM
29. installing the program click the Next gt button During the install process a Windows Command Prompt may pop up No interaction is required in this window it is automatically installing or updating the device s USB drivers Please let this process complete before closing the software installation wizard Congratulations You have just successfully installed the DAQ Central Program on your PC To end installing the program and close the setup wizard click the Close Button 4 3 v Software 4 3 DAQ Central Software Operation Below is the basic flow of operation when using the software 1 Highlight desired device 2 Open Device Configuration window 3 Set channels sample rate triggering and data output file 4 Click OK to confirm Device Configuration 5 Open any desired Data Displays 6 Click the Start button Details on the various windows and options can be found in the rest of this chapter Omega DAQ Central 700hatwt DAQ2401DEMO Figure 4 4 Main Control Window 4 4 Software V TOOLBAR BUTTONS Start Button Stop Button a Device Configuration 1j Icon Gauges Display Gauges Button Bars Display Bars Button Digital Display Digital Button Table Table Display Button Waveforms Waveforms Display Button Device Display List m Initiates data acquisition for the highlighted device Even if a Start Trigger is set this must be pressed to Arm the device
30. isition unit These files can also be downloaded from the omega com website should you misplace your CD e DAQ Central data logging software installer e Omega DAQ NET API When using Omega DAQ modules to acquire data computer energy save modes can cause false data readings Prior to using Omega DAQ modules ensure your computer s energy save mode is disabled If needed consult your PC user s manual to disable energy save power suspension modes 4 2 Sofrware Installation 4 2 1 System Requirements Minimum Requirements l rocessor 800 MHz Hard Drive Space 300 megabytes Ram 512 megabytes or higher 1 Available USB Port CD ROM Drive or Internet connection e Windows XP Service Pack 3 32 bit Windows Vista 32 bit Windows 7 32 bit or Windows 7 64 bit Recommended Requirements Processor 1 5 GHz Hard Drive Space 300 megabytes e Ram 1 5 gigabytes 1 Available USB Port CD ROM Drive or Internet connection e Windows XP Service Pack 3 32 bit Windows Vista 32 bit Windows 7 32 bit or Windows 7 64 bit 4 2 2 Software Setup Insert the DAQ Central Software CD that was included with your DAQ unit into the CD ROM drive on your PC Your system should begin the installation process automatically If the software installation does not start automatically open My Computer double click your CD ROM drive and run setup exe LL lx Welcome to the DAQ Central Setup Wizard The installe
31. l 5 2 Signal Management V The following table provides general advice regarding the selection of Scan Time The concepts are further illustrated by the figure Examples of Under Sampling Scan Time Measurement Scan Rate Analog Input Signal Duration Sample Rate Resolution Steady or gradual change Long Low High Highly variable unsteady Short High Low 25 C JD k 24 freti ty ah Se hs D Ta te LENS EN 22 St Time 1 sample per division e 1 sample per 3 divisions sssssss 1 sample per 4divisions Figure 5 1 Examples of Under Sampling The above figure depicts three signals from the same temperature fluctuations Under Sampling aliasing is evident in two of the signals Elaboration follows Signal 1 This signal based on 1 sample scan per division is represented by a heavy solid line and sample points designated by polygon symbols The signal represented is a fairly accurate portrayal of the actual temperature fluctuations Signal De ote This signal based on 1 sample scan every 3 divisions is represented by a heavy dotted line and sample points designated by squares Under sampling has resulted in a distortion in effect a lower amplitude than that exhibited by the first signal even though each measured point is accurate Signal3 This signal based on 1 sample scan every 4 divisions is represented by a dotted dashed line and sample points designated by plus
32. led the reading for example with increased resolution a reading of 5 12 V could become 5 11896 V The DAQ actually provides for 24 bits of data information however the accuracy of the least significant bits becomes less as the measurement duration speeds up At a scan time greater than 6 5 seconds the last 1 5 bits are considered unreliable resulting in a resolution of 22 5 bits At a very fast scan time 1 milliseconds the seven most least significant bits are unreliable resulting in 17 bit accuracy When you select the Scan Time you also determine the scan sample rate and resolution for the applicable channel For the DAQ s analog input applications scan sample rates range from 0 0002778 samples sec up to 1000 samples sec and corresponding resolution ranges from 22 5 to 17 bits g Signal Management Resolution Scan Rate Scans ENOB Speed Designation per Second SPS RMS Very Slow 50 60 Hz rejection 3600s gt ST gt 6 5s 0 0002778 lt SR lt 22 5 0 153 Slow 50 Hz rejection 6 5s gt ST gt 1s 0 153 lt SR lt 1 21 Slow 60 Hz rejection 1s ST gt 0 6s 1 lt SR lt 1 67 20 9 Medium 60 Hz rejection 0 6s gt ST gt 0 3s 1 67 lt SR lt 3 33 20 4 Medium 50 Hz rejection 0 3s gt ST gt 0 2s 3 33 lt SR lt 5 20 3 Medium 0 2s gt ST gt 0 05s 5 lt SR lt 20 19 2 Fast 0 05s gt ST gt 0 02s 20 lt SR lt 50 18 7 Very Fast 0 02s gt ST gt 0 001s 50 lt SR lt 1000 17 Table 5 1 Scan
33. mmas or tabs as the delimiter and the time can be saved as Elapsed Time or as a Date Time stamp There are three Save Behavior options Device Configuration AZ00haWK Channels Triggers Data IV Save data to file File type Binary x File c Documents and SettingsNAdministratorNDesktopNA 700haWK bin Browse Save Behavior Auto overwrite Y Add creation time to filename TS Auto overwrnte Prompt for overwrite FIG 4 17 Data Save Behavior Options Auto overwrite If a file with the same name already exists it will be automatically overwritten when the Start Acquisition button is pressed Prompt for If a file with the same name already exists a prompt overwrite will appear when the Start Acquisition button is pressed Add creation A timestamp is added to the filename in the format time to YYYY MM DD hhmm ss For example MyFile bin filename becomes MyFile 201 1 1031 1121 03 bin The timestamp will be automatically added every time the Start Acquisition button is pressed so multiple acquisitions can be easily stored to the same folder without revisiting the Device Configuration window Data Displays From the Main Window you can choose to view live data from any combination of Gauges Bars Digital Displays Tables and Waveforms These displays can be opened by clicking the appropriate button in the Main Window 4 11 Sofrware El Omega DAQ Central Gauges Figure 4 19 Gauge
34. mmediately report any damage to the shipping agent _ The carrier will not honor any damage claims unless all shipping material is saved for inspection After examining and removing contents save packing material and carton in the event reshipment is necessary 2 2 Included Items The following items are supplied in the box 1 Omega OM DAQ USB 2401 data acquisition module 1 Omega DAQ Central software CD e 1 USB Cable e 1 9Vdc Power Adaptor 1 Mounting Kit 8 screws 2 mounting brackets 2 DIN rail adaptors 1 Omega screwdriver e 1 OM DAQ USB 2400 Series User Manual this one M 5025 e 1 OM DAQ USB 2400 Series Quickstart Manual MQS 5025 2 Type K Thermocouples with Stripped Leads Hardware Setup Section 3 Hardware Setup 3 1 OM DAQ USB 2401 System Components le 127 5 00 gt 7 107 88 Z TANNVHO ERE ND 4 20 OM DAQ USB 2400 SERIES 97 USB DATA ACQUISITION SYSTEM 3 80 CHANNEL 1 amp 2 A CHANNEL 3 amp 4 ANALOC our ANALOG INPUT EXE 355 o1 re TA SE el Er 1 1 0 2 2 O X O 313 101414 O X O HJLIMIH L MICIM H L M H L M CIM POWER SUPPLY POWER LED STATUS LED DIMENSIONS mm in USB PORT Figure 3 1 OM DAQ USB 2401 Hardware and Dimensions W The external power port is used in applications which have USB hubs that are not self powered See the next section for more information The STATUS LED blinking at Scan Rate mean
35. nificant bits decreases as the measurement duration speeds up When measuring variable input signals as opposed to relatively steady input signals the variable signals will require more samples sec to obtain a realistic signal representation At a scan time greater than 6 5 seconds the last 1 5 bits are considered unreliable resulting in a resolution of 22 5 bits At a very fast scan time 1 millisecond the seven least significant bits are unreliable resulting in 17 bit accuracy When you select the Scan Time you also determine the scan sample rate and resolution for the applicable channel For the DAQ s analog input applications scan sample rates range from 0 0002778 samples sec 1 hr scan up to 1000 samples sec m scan and corresponding resolution ranges from 22 5 to 17 bits 4 10 Automatic Calibration The DAQ unit contains a built in source for performing automatic self calibrations These calibrations can be performed between scans periodically throughout the measurement process as indicated in the following figure Such calibration ensures accurate measurements even in environments that experience significant temperature fluctuations The figure below shows an initial calibration followed by the scan calibrate scan calibrate pattern _ __ The continuous calibration feature is built into the DAQ system With Auto Calibration enabled you mayn experience slower sample rates especially with multiple channels t
36. ntial gt 10V i nded v or fsm etntet stev s 8 ingeEnded gt Sn etode iv GL Figure 4 9 Configuration Mode Channels Tab Screen Channels Tab The Channels tab contains a spreadsheet designed for setting up channels for data acquisition Depending on the column you can make changes to the information contained in a cell by placing the mouse cursor in the cell All columns except Channel are editable Those with drop down arrows are limited to the choices in the drop down list You can use your PC s keypad arrow and tab keys to select new active cells in the spreadsheet Software V Configuration Parameter Settings Channel Nickname Units On Off Single Diff Range Scale and Offset The input channel s name not editable ANID analog channel 1 differential input ANTH analog channel 1 single ended high input ANIL analog channel 1 single ended low input Etc You can specify the Nickname e g Oven 1 Monitor Room You can specify the Engineering Unit When switching between voltage and thermocouple ranges this will automatically switch to the default units for that range However any units label may be typed in here To turn on or turn off the selected input channel You can select input channel as Single ended or Differential input You can select the voltage input range or thermocouple type for each input channel Thermocouples must always be u
37. onal safety and hazard symbols in accordance with IEC standards It is important to read and follow all precautions and instructions in this manual before operating or commissioning this device as it contains important information relating to safety and EMC Failure to follow all safety precautions may result in injury and or damage to your device Use of this device in a manner not specified will void your warranty IEC symbols Description Caution refer to accompanying documentation K EU s Waste Electrical and Electronic Equipment Compliance Figure 1 1 IEC Symbols 1 3 Statement on CE Marking It is the policy of OMEGA to comply with all worldwide safety and EMI EMC regulations that apply OMEGA is constantly pursuing certification of its products to the European New Approach Directives OMEGA will add the CE mark to every appropriate device upon certification For additional information see Section 10 Approvals amp Regulatory Compliance 1 4 General Description amp System Components 1 2 The OM DAQ USB 2401 is a USB 2 0 full speed thermocouple voltage input data acquisition module fully compatible with both USB 1 1 and USB 2 0 ports This stand alone module draws power from the USB port to operate An external optional power supply can be used All configurable options including individual channel input type and range are software programmable The OM DAQ USB 2401 has user programmable voltage inputs that range
38. own The noise spikes having the same polarity phase and magnitude in each input signal cancel each other out This results in a clean differential signal 51 S2 Floating differential measurements are made when low level signals must be measured in the presence of high levels of common mode noise e g a non grounded thermocouple When the signal source has no direct connection to the system analog common one must be provided In Omega Daq the connection to analog common is provided in the circuitry with both the channel high and channel low connected to analog common Both of these connections to common are made through 1 MQ resistors No additional connections of channel high and low to common should be made MUX gt PD1 AOL Figure 5 4 Example of Floating Differential Circuit Differential signal hookups do not provide isolation or any kind of circuit protection 5 5 g Signal Management 5 6 Resolution An analog to digital converter ADC converts an analog voltage to a digital number The digital number represents the input voltage in discrete steps with finite resolution ADC resolution is determined by the number of bits that represent the digital number An n bit ADC has a resolution of 1 part in 2n Thus 12 and 16 bit resolutions are as follows e 12 bit resolution 1 part in 4096 212 corresponding to 2 44 mV in a 10 V range e 16 bit resolution 1 part in 65 536 216 corresponding to 0 153 mV in
39. r will guide you through the steps required to install DAQ Central on your computer WARNING This computer program is protected by Sopa lw and namaos venter Unauthorized chasse lb UD EDEN 20 WV ONO VE map ein sever cd or criminal penalties and will be prosecuted to the maximum extent possible under cot o5 Figure 4 1 Welcome Screen This welcome screen should be visible on your computer screen To continue with installing the program click the Next gt button From this screen you select the folder were you want the program files installed on your PC The default setting will install the software under your Program folders in a new folder named Omega To continue with installing the program click the Next gt button rr sl Select Installation Folder ASM The installer will install DAQ Central to the following folder To install in this folder click Next To install to different folder enter it below or click Browse Folder C Program Files Omega DAQ Central Browse Disk Cost Figure 4 2 Select Install Screen 4 2 Software 18 DAQ Central J1O xl Confirm Installation 1 AS JON The installer is ready to install DAQ Central on your computer Click Next to start the installation Figure 4 3 Confirm Installation Screen The setup wizard now has all the information to complete the installation of the software on your PC To continue with
40. rdware 0000000000000000000000000000000000000000000000000000000000000000000000000 2 1 2 1 Package Insp ti n Gardene 2 1 2 2 Included SR EN 2 1 Section 3 Hardware Setup 00000 0000000000000 000000000 00000000000 0000000000000000000000000 3 1 3 1 ONM DAUDSUSB 2400 Components v rende 3 1 3 2 USB Hubs and Power Adaptors varse neset 3 1 O1 USB powered HUDS ammende 3 2 3 22 DEM PO Were HUDS EE 3 2 3 2 3 POWER Adapt rs aiu obra ison terere kind oU nb KEERT ES 3 2 3 3 Connecting Your OM DAQ USB 2401 Acquistition Systems To PC 3 3 3 4 Connecting Various Hardware Setups aaa 3 4 3 4 1 Direct Connection To Computer USB Port s 3 4 3 4 2 Connection T USB powered Hub 5er tern 3 5 3 4 3 Connections To Self powered and USB powered Hubs 3 5 35 OM DACG USB 240 MOUNTO uuuasassasaaqpaasasuchussisaausyhuns 3 6 3 5 1 OM DAQ USB 2401 Wall Mounting 3 7 3 52 OM DAQ USB 2401 DIN Rail Mounting 3 8 Section 4 mi Software 000000000000000000000000000000000000000000000000000000000000000000000000000 4 1 EE ge GE 4 1 ee Installati fi REE 4 1 44 1 System Req in ements saccos epe itt sint navn 4 1 4 2 2 SORE Wate DOLUD JRR 4 2 4 3 DAQ Central Software Operation ease iren os rEUHaw ERE iiit inp an 4 4 4 3 1 Main Control Window Pull Down Operations 4 6 4 3 2 Device Configuration sassanidene 4 8
41. rms may be used in a different manner Choosing between differential and single ended inputs is made by software command The following text briefly describes the two signal modes Single ended mode refers to a mode or circuit set up in which a voltage is measured between one signal line and common ground voltage Vcm The measured voltage may be shared with other channels The advantage of a single ended non differential mode over differential mode is that it provides for a higher channel count for example 16 channels instead of 8 _ In DAQ applications thermocouples should not be connected single ended Doing so can result in noise and false readings This is especially true when acquiring other high amplitude signals in conjunction with thermocouple signals that are connected single ended Signal Management V Differential mode refers to a mode or circuit set up in which a voltage is measured between two signal lines The measured differential voltage is used for a single channel An advantage of using differential inputs is that they reduce signal errors and the induction of noise resulting from ground current The following illustration is an example of how noise is reduced or canceled out when using the differential WW Noise Reduction in Differential Mode Figure 5 3 Noise Reduction in Differential Mode In the schematic voltage signal S2 is subtracted from signal S1 resulting in the output signal sh
42. s Screen Figure 4 20 Bars Screen 5 36 V 27 06C 27 06 C Figure 4 21 Digital Screen Figure 4 22 Table Screen Software V old Fet vottene M 14 T D 75 0000 150 0000 208 5000 Waveform 2 f 1 Oven 1 C 110 Io 70 i 1 1 1 I 75 0000 100 0000 150 0000 2085000 I Dwfaveform Figure 4 23 Waveform Screen Each Data Display can be customized by clicking the Options Icon Each Data Display s Options screen lets you choose which device channels to display in that window Channels can be added or removed with the Add Display and Delete Display buttons Confirm changes by clicking the OK button Start Acquisition by clicking the Play button on the Main Window Acquisition can be stopped with the Stop button On the Waveforms screen it is also possible to adjust the graph range by clicking on the high and low values of the Y axis and entering new values irs Number of columns 22 24 Ref Voltage Device A700hawK Oven 2 Channel ovni v Min 3024 Max 1024 Decimal Places 03 OK Cancel J Figure 4 24 Sample Options Screen g Software 4 4 Power Line Rejection The OM DAQ USB 2401 Series can take readings while making use of 50 60Hz line cycle rejection While in the line cycle rejection mode the maximum sample rate is as follows e 50 Hz rejection
43. s an acquisition is in progress At a fast scan rate the STATUS LED appears solid The POWER LED in solid means the unit has power 3 2 USB Hubs and Power Adaptors With the use of USB hubs you can connect up to 10 DAQ units to one PC USB hubs can be of the self powered type or of the USB powered type Both types of hubs are available from a variety of vendors 3 1 g Hardware Setup 3 2 3 2 1 USB powered Hubs These hubs draw all power from the host USB connector s power pins The power is used for hub internal functions and for the hub s ports Each port of a USB powered hub must be capable of supplying at least 100 mA 3 2 2 Self powered Hubs These hubs draw power from a source other than the host USB connector with exception that they may draw up to 100 mA from their upstream connection for hub internal functions The external power is used for hub internal functions and for the hub s ports Each port of a self powered hub must be capable of supplying 500 mA 3 2 3 Power Adaptors Power adaptors also referred to as auxiliary power packs are required for some self powered hubs and for DAQ modules that are powered from USB powered hubs In addition DAQ units will require the use of a power adaptor when used with certain laptops _ Nu Y When using a power adaptor with your DAQ system be sure to supply power from the adaptor to the DAQ unit before connecting the USB cable This allows the DAQ to inform
44. sed with Differential input You can rescale the input signal This scaled offset value will appear in all data displays and in any saved data files Sampling can be set in terms of Scan Rate or Scan Time Scan Rate 1 Scan Time For example if you are acquiring 4 voltage inputs at 250 Hz you will receive 250 complete scans per second Meaning each channel will send 250 pieces of data every second for a total of 4 x 250 1000 pieces of data The maximum scan rate is affected by the number of channels turned on Selecting thermocouple input also lowers the maximum scan rate e Scan Rate scan sec 500 000 4 Hz Max rate 500 000 Hz Scan Time sec scan Figure 4 10 Scan Options Thermocouple Units c Figure 4 11 Units Options IV Auto Calibration Figure 4 12 Automatic Calibration 4 9 g Software Device Configuration A700ha WK j xl Channels Triggers Data Start Trigger Stop Trigger Manual 7 The Triggers tab is used to set up triggers for starting and stopping data acquisition The Start Trigger and the Stop Trigger each have a different set of available trigger types Figure 4 13 Trigger Options Device Configuration A700haWK Channels Triggers Data Start Trigger Manual Manual Emaan m Date Time Manual y Figure 4 14 Start Trigger Options B Device Configuration A700haWK Channels Triggers Data
45. signs Fewer samples a greater degree of under sampling has resulted in a further distortion and lowering of signal amplitude From these examples it should be realized that more samples scans will result in a more accurate representation of the actual signal and that under sampling will tend to lower the amplitude of the signal exhibiting a trend toward a flat line state As stated earlier the more variability a signal has the more samples that are needed to accurately portray it 5 3 g Signal Management 5 4 5 4 Triggering Triggering controls an acquisition cycle Once the system is armed a trigger is required to collect the data The user must determine the triggering requirement based on the nature of the measurement and the amount of data needed to satisfy the system s purpose The trigger source can be a software command or an analog input channel on reaching a specified voltage level can be used to trigger the system IMMEDIATE TYPEOF START TIME TRIGGER SOURCE Fe CHANNEL VALUE RISING FALLING TRIGGER EVENT POST TRIGGER SCAN COUNT I l III HI TIME SCAN GROUP aM PERIOD N Figure 5 2 Trigger Source Diagram 5 5 Signal Modes OM DAQ USB 2401 units operate in one of two modes 1 single ended mode or 2 differential mode These terms single ended mode and differential mode apply to their use in this manual In other sources these te
46. sition and check the Triggers tab of the Device Configuration window A trigger may be set to start acquisition at a future date Try setting both Start and Stop triggers to manual and restarting acquisition The Device Configuration screen is grayed out A data acquisition may be running A device s configuration can not be edited during acquisition The waveform scale is too small large The vertical scale can be adjusted by clicking the max and min values on the y axis The horizontal scale can be adjusted from the Waveform Options screen which is accessed by clicking the Options button at the top of the Waveform window The Scans to graph setting determines how many data points scans will appear along the x axis A higher number shows a greater span of time but uses more of the PC s RAM and may slow it down The main DAQ Central window does not respond A configuration window may be open Configuration windows must be closed before continuing to interact with the software Check your desktop and Windows taskbar for a Device Configuration window or an Options window The device does not appear in the device list Select Detect Devices from the Device menu to re scan for connected devices See also Power under Basic Checklist and USB drivers in this section Thermocouple inputs are noisy If you experience noise from thermocouple wires you can connect a 100K resistor from AxL to COM to eliminate some nois
47. the host computer upon connection of the USB cable that the unit requires minimal power from the computer Power adaptors for use with the DAQ have a current limit of 500 mA min and a voltage range of 7 5 to 12 Volts DC These specifications are provided on the end face of the DAQ unit If the computer does not recognize the DAQ unit make sure the computer s USB port is properly enabled and is in good working order If the computer still fails to recognize the DAQ unit the use of an external 9v DC power adaptor may be required EN The use of certain notebook computers may require the use of a power adaptor with your DAQ unit Hardware Setup V 3 3 Connecting Your OM DAQ USB 2401 Acquisition System to PC When using a power adaptor with your DAQ system be sure to supply power from the adaptor to the DAQ before connecting the USB cable This allows your DAQ to inform the host computer upon connection of the USB cable that the unit requires minimal power from the computer Use an approved high speed USB cable to connect the DAQ system to one of the host computer s USB ports There is no need for an additional power source in this setup since the power pins of the PC s USB connection supply 500 mA at 4 to 5 25 V Additional setup examples are described in this chapter some of which involve USB hubs and or power adaptors Fig
48. this example two OM DAQ USB 2401s are connected by cable to individual ports of a single USB powered hub Since the hub receives all its power from the computer s USB the hub cannot supply adequate power to the DAQ units Because of this aspect of insufficient power each unit is connected to its own power adaptor Figure 3 4 Connection to USB Powered Hub END ANN The power adaptors used must be capable of supplying at least 500 mA and have a voltage rating of 7 5 to 12 Vdc 3 4 3 Connections to Self Powered and USB powered Hubs This example illustrates a system that makes use of four DAQ units and two different style USB hubs Two DAQs are connected by cable to individual ports of a self powered USB hub In addition the self powered hub is connected to a downstream USB powered hub which is also connected to two DAQ units Notice that the DAQ units connected to the self powered hub have no adaptors connected to them This is because the hub receives external power in addition to the PC supplied USB power which is capable of supporting the downstream devices connected directly to it In comparison the three OM DAQ USB 2401s connected to the USB powered hub each require their own power adaptor As in example 3 4 2 the power adaptors used must be capable of supplying at least 500 mA and have a voltage rating of 47 5 to 12 Vdc g Hardware Setup POWER ADAPTER POW
49. uency A lowpass filter attenuates frequencies above the cutoff frequency Conversely a high pass filter attenuates frequencies below the cutoff As frequency increases beyond the cutoff point the attenuation of a singlepole low pass filter increases slowly Multi pole filters provide greater attenuation beyond the cutoff frequency but may introduce phase time delay problems that could affect some applications Signal Management 5 9 Input and Source Impedance As illustrated below the input impedance Ri of an analog to digital converter combines with the transducer s source impedance Rs forming a voltage divider This divider distorts the voltage being read at the analog to digital converter The actual voltage read is represented by the equation VADC VT x Ri Rs Ri The input impedance Ri of most ADCs is at least 1 MQ low source impedance Rs usually presents no problem Some transducers such as piezoelectric types have high source impedance and should therefore be used with a charge sensitive amplifier of low output impedance As described in the following paragraphs multiplexing can greatly reduce the effective input impedance of an analog to digital converter Analog to Digital Converter Digital Outputs V Figure 5 5 Analog to Digital Converter 5 10 Crosstalk Crosstalk is a type of noise related to source impedance and capacitance in which signals from one channel leak into an adjacent chann
50. unit using the adapter the ferrite cores must be attached to both the USB cable and the power adapter to meet EFT Flectrical Fast Transient specifications Refer to Figure 6 1 lt ay POWER f ADAPTER il x J FZ Den A Ye SS MIDPOINT OF CABLES SS FR V A A Figure 6 1 OM DAQ USB 2401 with Ferrite Cores Installed To maintain CE certification and install the ferrite cores perform the following 1 Using a small screw driver or other suitable instrument unsnap the ferrite core to open it as shown in Figure 6 2 2 Install one ferrite core on each far end of the USB cable and one ferrite core in the middle of the cable as shown in Figure 6 1 3 Install one ferrite core on each far end of the power adapter and one ferrite core in the middle of the cable as shown in Figure 6 1 CE Conformity UNSNAP FERRITE CORES HERE Figure 6 2 Ferrite Core The ferrite cores may be removed from the DAQ unit however in order to conform to CE standards all of the ferrite cores must be attached to the USB cable and power adapter If the user is not using the power adapter but relying on power from the host USB connection no ferrites are required 6 2 v Troubleshooting Section 7 Troubleshooting 7 1 Basic Checklist Power Check USB cable connection The green PWR IND LED should be lit on the DAQ device If using a powered USB hub make sure its pow
51. ure 3 2 Connection of an OM DAQ USB 2401 System to a Computer USB Port Certain notebook computers require the use of a power adaptor with your DAQ unit 3 3 g Hardware Setup 3 4 Connecting Various Hardware Setups ON DAQ USB 2401 data acquisition systems range from simple to complex One example of a simple system is that of one OM DAQ USB 2401 connected to a PC s USB connector A much more complex system is one that contains 10 OM DAQ USB 2401 units and a combination of USB powered and self powered hubs Despite the wide range of possibilities in between use of the following examples should enable you to properly connect your system EN AN In the examples that follow the USB hubs have four external ports downstream ports The USB hubs used in your system may have more Connections can be adjusted accordingly 3 4 1 Direct Connection to Computer USB Port s In this example one DAQ unit is connected by cable to one of the computer s USB ports The number of USB connectors may vary from PC to PC When you connect DAQ units directly to a USB connector in this manner no additional power source is required since the computer s USB connector power pins supply the DAQ with adequate power 500 mA at 4 75 to 5 25 V Figure 3 3 Direct Connection to a Computer USB Port s Hardware Setup 3 4 2 Connection to USB powered Hub In
52. urned on INITIAL CALIBRATION SCAN CALIBRATION SCAN CALIBRATION SCAN CALIBRATION tiiii SCAN PERIOD m TIME Figure 4 27 Calibration Scan Arrangement g Software 4 11 Thermocouple Measurements The OM DAQ USB 2401 provides effortless thermocouple TC measurements The unit includes built in cold junction compensation CJC which is automatically invoked when you select TC measurements The DAQ unit automatically converts acquired voltage readings into compensated linearized temperature readings A DAQ system can make thermocouple and volts measurements concurrently Signal Management V Section 5 Signal Management 5 1 Channel Control and Expansion In the OM DAQ USB 2401 system the quantities and types of DAQ units used determine the system s channel capacity Up to 10 OM DAQ USB 2401s can be used with one host PC See the Specifications for more detailed channel information 5 2 Scan Time and Resolution 5 2 1 Scan Time Scan Time per scan The amount of time used for scanning sampling all selected channels input signal For the OM DAQ USB 2401 the scan rates range from very slow 1 hour per scan to very fast 1 milliseconds per scan 5 22 Resolution Effective Number of Bits ENOB RMS Resolution Effective Number of Bits ENOB RMS The number of reliable data bits that exist for a signal s measurement The greater the resolution the more detai

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