Home

National Instruments SCB-68 User's Manual

1. Figure B 7 NI 7811R 7831R Devices SCB 68 Shielded Connector Block User Manual B 8 ni com Fuse and Power One of the 5 V lines from the DAQ device pin 8 is protected by an 800 mA fuse Pin 14 is also 5 V but it is not fuse protected on the SCB 68 Shorting pin 14 to ground blows the fuse which is usually socketed If the SBC 68 does not work when you turn on the DAQ device first check the switch settings then check both the 800 mA fuse on the SCB 68 and the output fuse if any on the DAQ device Before replacing any fuses check for short circuits from power to ground A 470 Q series resistor R21 filters the 5 V power on the SCB 68 As the filtered 5 V is loaded the voltage decreases Pad R20 is in parallel with R21 and you can install a resistor if needed Shorting R20 bypasses the filter while capacitively coupling DGND and AGND and this configuration is not recommended N Caution NI is not liable for any device damage or personal injury resulting from improper use of the SCB 68 and the DAQ device Refer to Figure 2 1 SCB 66 Printed Circuit Diagram to locate the fuse and other components on the SCB 68 A suitable replacement fuse for the SCB 68 is made by Littelfuse and has part number 235 800 National Instruments Corporation C 1 SCB 68 Shielded Connector Block User Manual SCB 68 Circuit Diagrams This appendix contains illustrations of circuit diagrams for the SCB 68 5V
2. V AGND ACH lt i 8 gt Figure 5 1 Analog Input Channel Configuration Diagram for ACH i and ACH lt i 8 gt Table 5 1 Component Location for Analog Input Channels in DIFF Input Mode Channel A B C D E F G ACHO R22 RC12 RC13 R23 RC4 R4 R5 ACHI R24 RC14 RC15 R25 RCS R6 R7 ACH2 R26 RC14 RC17 R27 RC6 R8 R9 ACH3 R28 RC18 RC19 R29 RC7 R10 R11 SCB 68 Shielded Connector Block User Manual 5 2 ni com Chapter 5 Adding Components for Special Functions Table 5 1 Component Location for Analog Input Channels in DIFF Input Mode Continued Channel A B C D E F G ACH4 R30 RC20 RC21 R31 RC8 R12 R13 ACH5 R32 RC22 RC23 R33 RC9 R14 R15 ACH6 R34 RC24 RC25 R35 RC10 R16 R17 ACH7 R36 RC26 RC27 R37 RCII R18 R19 Conditioning Analog Output Channels Figure 5 2 illustrates the generic AO channel pad configuration and Table 5 2 describes the AO component locations and labels Figure 5 3 shows the AO channel configuration for DACOOUT ee Ee Figure 5 2 Analog Output Channel Configuration Diagram Table 5 2 Component Location for Analog Output Channels in DIFF Input Mode Channel A B DACOOUT R3 RC3 DACIOUT R2 RC2 National Instruments Corporation 5 8 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components
3. Extended Thermocouple Thermocouple Grade Cover Type Positive Color Negative Color Cover Color Color B Gray Red Gray C White Red Trace Red White Red Trace E Purple Red Brown Purple J White Red Brown Black K Yellow Red Brown Yellow N Orange Red Brown Orange R Black Red Green S Black Red Green U Black Red Green T Blue Red Brown Blue National Instruments Corporation 4 1 SCB 68 Shielded Connector Block User Manual Chapter 4 Using Thermocouples The maximum voltage level thermocouples generate is typically only a few millivolts Therefore you should use a DAQ device with high gain for best resolution You can measure thermocouples in either differential or single ended configuration The differential configuration has better noise immunity but the single ended configurations have twice as many inputs The DAQ device must have a ground reference because thermocouples are floating signal sources Therefore use bias resistors if the DAQ device is in DIFF input mode For a single ended configuration use RSE input mode For more information on field wiring considerations refer to the NI Developer Zone tutorial Field Wiring and Noise Considerations for Analog Signals located at ni com zone Cold junction compensation CJC with the SCB 68 is accurate only if the temperature sensor reading is close to the actual temperature of the screw terminals When you read thermocoup
4. esee 5 23 Special Considerations for Digital Inputs eee 5 24 Appendix A Specifications Appendix B Quick Reference Labels Appendix C Fuse and Power Appendix D SCB 68 Circuit Diagrams Appendix E Soldering and Desoldering on the SCB 68 Appendix F Technical Support and Professional Services Glossary Index National Instruments Corporation ix SCB 68 Shielded Connector Block User Manual About This Manual Conventions This manual describes the SCB 68 and explains how to use the connector block with National Instruments data acquisition DAQ devices lt gt Pg bold italic monospace The following conventions appear in this manual Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name for example DIO lt 3 0 gt The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked on the device refer to the Safety Information of Chapter 1 Introduction for precautions to take Bold text denotes items that yo
5. 9 e AISENSE jaw L Measurement Device Configured in DIFF Input Mode AISENSE is not present on all devices Figure 3 2 Differential Input Connections for Ground Referenced Signals With this connection type the instrumentation amplifier rejects both the common mode noise in the signal and the ground potential difference between the signal source and the DAQ device ground shown as V4 in Figure 3 2 SCB 68 Shielded Connector Block User Manual 3 6 ni com Chapter 3 Connecting Signals Differential Connections for Nonreferenced or Floating Signal Sources Figure 3 3 shows how to connect a floating signal source to a channel on the DAQ device configured in DIFF input mode ACH or ACH i Instrumentation Amplifier Floating z Signal Source e E Measured Voltage ACH or ACH lt i 8 gt P e O Bias Resistor see text 64 e AISENSE AIGND 1 0 Connector Measurement Device Configured in DIFF Input Mode AISENSE is not present on all devices Figure 3 3 Differential Input Connections for Nonreferenced Signals Using Bias Resistors Figure 3 3 shows a bias resistor connected between ACH or ACH lt i 8 gt and AIGND This resistor provides a return path for the 200 pA bias current A value of 10 kQ to 100 kQ is usually sufficient If you do not use the resistor and the source is truly floating the source is not lik
6. p gt AOGND Screw Terminal p gt DAC1OUT Screw Terminal p gt AOGND Screw Terminal National Instruments Corporation Figure D 4 Analog Output Circuitry D 3 SCB 68 Shielded Connector Block User Manual Soldering and Desoldering on the SCB 68 Some applications discussed here require you to make modifications to the SCB 68 usually in the form of adding components to the printed circuit device To solder and desolder components on the SCB 68 refer to Figure 2 1 SCB 68 Printed Circuit Diagram and to Figure E 1 and complete the following steps to remove the SCB 68 from its box 1 Quick Reference Label 4 Lock Washers 8 Strain Relief Bars 2 Cover 5 Shielding Screws 9 Strain Relief Screws 3 68 Pin Connector 6 68 Pin I O Connector 10 Circuit Card Assembly Screws 7 Base Figure E 1 SCB 68 Parts Locator Diagram iy Note Ifthe kit is missing any of the components in Figure E 1 contact NI by selecting Contact NI at ni com National Instruments Corporation E 1 SCB 68 Shielded Connector Block User Manual Chapter E Soldering and Desoldering on the SCB 68 1 Disconnect the 68 pin cable from the SCB 68 if it is connected 2 Remove the shielding screws on either side of the top cover with a Phillips head number 1 screwdriver You can now open the box 3 Loosen the strain relief screws with a Phillips head number 2 screwdriver 4 Remove the signal wir
7. Input Signal Source Type Floating Signal Source Not Connected to Building Ground Grounded Signal Source Examples Ungrounded thermocouples Signal conditioning with Isolated outputs Battery devices Examples Plug in instruments with nonisolated outputs ACH F OT gt Y Refer to the Using Bias Resistors section for information on bias resistors Differential e DIFF Common l n Common Mode AIGND Mode AIGND Voltage Voltage Refer to the Using Bias Resistors section for information on bias resistors NOT RECOMMENDED ACH ACH gt 4 N V4 Mee b Single Ended I oe A Ground Common Referenced E volta AIGND ommon RSE Mode Voltage Ground loop losses Vg are added to measured signal ACH ACH ii Ovi AISENSE v dy AISENSE Single Ended Nonreferenced common Common NRSE Mode e n AIGND Mode AIGND Voltage Voltage S77 Figure 3 1 Summary of Al Connections SCB 68 Shielded Connector Block User Manual 3 2 ni com Chapter 3 Connecting Signals Nonreferenced or Floating Signal Sources A floating signal source is a signal source that is not connected in any way to the building g
8. E series devices quick reference label table 1 2 to 1 4 B 2 electromagnetic compatibility specifications A 3 environment specifications A 2 environmental noise See noise F floating signal sources bias resistors 3 7 description 3 3 differential inputs 3 3 3 7 to 3 8 recommended configuration figure 3 2 single ended connections RSE input mode 3 3 3 9 fuse location figure 2 2 specifications A 1 to A 2 troubleshooting C 1 G ground referenced signal sources description 3 4 differential inputs 3 4 3 6 recommended configuration figure 3 2 single ended inputs 3 4 to 3 5 3 9 to 3 10 ni com input modes See analog input signal connections installation 68 pin cables 1 5 to 1 6 connecting to SCB 68 figure 1 6 quick reference label table 1 2 100 pin cables 1 6 to 1 10 connecting to SCB 68 figure 1 7 pin assignments SCB 68 E Series I O Connector pinout extended AI figure 1 9 SCB 68 E Series I O Connector pinout extended digital figure 1 10 SCB 68 E Series I O Connector pinout full figure 1 8 quick reference labels table 1 2 connecting signals 2 3 hazardous voltages caution 2 1 installation categories 1 12 to 1 13 parts locator diagram figure 1 5 2 2 printed circuit diagram figure 2 2 L lowpass filtering 5 7 to 5 16 adding components 5 11 to 5 12 analog output and digital input lowpass filtering 5 12 differential lowpass filter 5 12 sin
9. Note This configuration is the factory default configuration Analog input and analog output SCB 68 Shielded Connector Block User Manual 2 4 ni com Chapter 2 Parts Locator and Wiring Guide Table 2 1 Switch Configurations and Affected Signals Continued Switch Setting Applicable Signals Single ended analog input Temperature Sensor S5 S4 S3 Q Signal Conditioning Circuitry Power On ES 1 e Single ended temperature sensor with accessory power enabled Differential analog input Temperature Sensor S5 S4 S3 Signal Conditioning Circuitry Power On O 1 O s2 Differential temperature sensor with accessory power enabled 1 When accessory power is enabled I O pin 8 is fused and is intended to be connected to 5V This setting is not recommended for use with the NI 653X NI 670X or NI 660X Refer to the device user manual at ni com manuals to determine if the device supplies 5 V to I O pin 8 Only applies to the signal conditioning circuitry 3 Except NI 61XX devices Refer to the device user manual at ni com manuals to determine if the device supports single ended inputs National Instruments Corporation 2 5 SCB 68 Shielded Connector Block User Manual Connecting Signals This chapter describes the types of signal sources that you use when configuring the channels and making signal connections to the S
10. GND 21 55 PB1 20 54 PBO 19 53 GND 18 52 PA6 17 51 PA5 16 50 GND 15 49 PAS 14 48 PA2 13 47 GND 12 46 PAO 11 45 5V 10 44 NC 9 43 NC 8 42 NC 7 41 NC 6 40 NC 5 39 NC 41 38 NC 3 37 NC 2 36 NC 1 35 NC No Connect PC7 GND GND PC4 GND GND PC1 GND GND PB6 GND GND PB3 PB2 GND GND PA7 GND GND PA4 GND GND PA1 GND GND NC NC NC NC NC NC NC NC NC Figure 1 6 SCB 68 E Series 1 0 Connector Pinout Extended Digital SCB 68 Shielded Connector Block User Manual 1 10 ni com Chapter 1 Introduction Configuring the SCB 68 For instructions about using Measurement amp Automation Explorer MAX to configure the SCB 68 as an accessory for a DAQ device complete the following steps 1 Navigate to MAX by selecting Start Programs National Instruments Measurement amp A utomation 2 Select Help Help Topics NI DAQ in MAX 3 Select DAQ Devices Configuring DAQ Devices Configuring DAQ Devices Accessory in the Measurement amp Automation Explorer Help for MAX Safety Information The following section contains important safety information that you must follow when installing and using the SCB 68 Do not operate the SCB 68 in a manner not specified in this document Misuse of the SCB 68 can result in a hazard You can compromise the safety protection built into the SCB 68 if the device is damaged in
11. 0 5 C of uncertainty to the measurement For best results you must use a well calibrated DAQ device so that offsets can be ignored You can eliminate offset error however by grounding one channel on the SCB 68 and measuring the voltage You can then subtract this value the offset of the DAQ device in software from all other readings SCB 68 Shielded Connector Block User Manual 5 6 ni com Chapter 5 Adding Components for Special Functions Thermocouple wire error is the result of inconsistencies in the thermocouple manufacturing process These inconsistencies or nonhomogeneities are the result of defects or impurities in the thermocouple wire The errors vary widely depending upon the thermocouple type and even the gauge of wire used but an error of 2 C is typical For more information on thermocouple wire errors and more specific data consult the thermocouple manufacturer For best results use the average of many readings about 100 or so typical absolute accuracies should then be about 2 C Lowpass Filtering This section discusses lowpass filtering and how to add components for lowpass filtering Theory of Operation Lowpass filters highly or completely attenuate signals with frequencies above the cut off frequency or high frequency stopband signals but lowpass filters do not attenuate signals with frequencies below the cut off frequency or low frequency passband signals Ideally lowpass filters have a phase s
12. Analog Output and Digital Input Lowpass Filtering Lowpass Filtering Applications eene eee Noise Filtering 2 d pone OI eee ee Amtiahlasing Piltering io tee ed te eres Special Consideration for Analog Input Channels sss Special Consideration for Analog Output Signals sss Special Consideration for Digital Trigger Input Signals Measuring a 4 to 20 mA Current nene emen rere Theory ot Operation nere SCB 68 Shielded Connector Block User Manual viii ni com Contents Selecting a ResIstOT niit epe re eret eit ui tae od RR ERAT eese 5 17 Adding Components cte iiiter ree tete Rr pe dread ede 5 18 Single Ended Inp ts tete ahi eere even 5 18 Differential Inputs ete etie eris 5 18 Attenuating Volt ge see e pt erede ae ede e ise the epe en 5 18 Theory of Oper tion inire aen eene 5 19 Selecting Components sce eiit tirer Heer Se the eer Rn 5 20 Accuracy Considerations essere 5 20 Adding Components ed ee eredi ortae es E Dea T epe 5 20 Single Ended Input Attenuators eese 5 20 Differential Input Attenuators esee 5 21 Analog Output and Digital Input Attenuators esses 5 22 Special Considerations for Analog Input eee 5 22 Special Considerations for Analog Output
13. which is determined by the input limits of the application is a value you apply to amplify or attenuate the signal Gain is expressed in decibels and is defined as Gain 20 Log f 5 2 Resolution or the smallest signal increment that can be detected by a measurement system is either 12 or 16 bits depending on the DAQ device Open Thermocouple Detection As an option you can build open thermocouple detection circuitry by connecting a high value resistor between the positive input and 5V A resistor of a few MQ or more is sufficient but a high value resistor allows you to detect an open or defective thermocouple If the thermocouple opens the voltage measured across the input terminals rises to 5 V a value much larger than any legitimate thermocouple voltage You can create a bias current return path by using a 100 kQ resistor between the negative input and AIGND National Instruments Corporation 5 5 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Differential Open Thermocouple Detection Use position A to connect a high value resistor between the positive input and 5V Leave the jumpers in place positions F and G for each channel used Single Ended Open Thermocouple Detection Sources of Error Use position A for one channel and C for the next channel when you connect a high value resistor between the positive input and 5V Leave the jumpers at positions F and G in
14. ACH lt i gt and ACH lt i 8 gt are used as two single ended channels configure the SCB 68 in its factory default configuration In the factory default configuration jumpers on the SCB 68 are in the two series positions F and G as shown in Figure 5 1 Analog Input Channel Configuration Diagram for ACH lt i gt and ACH lt i 8 gt In this configuration you should connect all signal grounds to AIGND hy Note Some versions of the SCB 68 use hardwired 0 Q resistors as the factory default jumpers In such cases to move these jumpers to and from the factory default positions you must solder and desolder on the SCB 68 circuit card assembly When soldering refer to Appendix E Soldering and Desoldering on the SCB 68 National Instruments Corporation 3 3 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals Ground Referenced Signal Sources 3 Note Some ve A grounded signal source is connected in some way to the building system ground therefore the signal source is already connected to a common ground point with respect to the DAQ device assuming that the host computer is plugged into the same power system Nonisolated outputs of instruments and devices that plug into the building power system fall into this category The difference in ground potential between two instruments connected to the same building power system is typically between 1 and 100 V but the difference can be much greater if the power dist
15. V as Figure 5 23 shows SCB 68 Shielded Connector Block User Manual 5 22 ni com Chapter 5 Adding Components for Special Functions e a Vin Ro Input Impedance Figure 5 23 Input Impedance Electrical Circuit Zin is the new input impedance Refer to Appendix A Specifications in the device user manuals at ni com manuals for the input impedance Equation 5 20 shows the relationship among all of the resistor values R x Input Impedance 5 20 in 4X R Input Impedance Special Considerations for Analog Output When you use the circuit shown in Figure 5 19 for AO the output impedance changes Thus you must choose the values for R and R so that the final output impedance value is as low as possible Refer to Appendix A Specifications in the device user manuals at ni com manuals for device specifications Figure 5 24 shows the electrical circuit you use to calculate the output impedance Ry Z Ws e lt out Output E R Impedance Figure 5 24 Electrical Circuit for Determining Output Impedance Equation 5 21 shows the relationship between R R2 and Zoun where Zout is the old output impedance and Z is the new output impedance Zour Ri X R2 Z out R R 5 21 out2 Z out National Instruments Corporation 5 23 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Special Considerat
16. any way If the SCB 68 is damaged return it to NI for repair Do not substitute parts or modify the SCB 68 except as described in this document Use the SCB 68 only with the chassis modules accessories and cables specified in the installation instructions You must have all covers and filler panels installed during operation of the SCB 68 Do not operate the SCB 68 in an explosive atmosphere or where there may be flammable gases or fumes Operate the SCB 68 only at or below the pollution degree stated in Appendix A Specifications Pollution is foreign matter in a solid liquid or gaseous state that can reduce dielectric strength or surface resistivity The following is a description of pollution degrees e Pollution Degree 1 means no pollution or only dry nonconductive pollution occurs The pollution has no influence e Pollution Degree 2 means that only nonconductive pollution occurs in most cases Occasionally however a temporary conductivity caused by condensation must be expected National Instruments Corporation 1 11 SCB 68 Shielded Connector Block User Manual Chapter 1 Introduction Pollution Degree 3 means that conductive pollution occurs or dry nonconductive pollution occurs that becomes conductive due to condensation Clean the SCB 68 with a soft nonmetallic brush Make sure that the SCB 68 is completely dry and free from contaminants before returning it to service You must insulate signal connections fo
17. drivers discussion forums a measurement glossary and so on Assisted Support Options Contact NI engineers and other measurement and automation professionals by visiting ni com ask Our online system helps you define your question and connects you to the experts by phone discussion forum or email e Training Visitni com custed for self paced tutorials videos and interactive CDs You also can register for instructor led hands on courses at locations around the world e System Integration If you have time constraints limited in house technical resources or other project challenges NI Alliance Program members can help To learn more call your local NI office or visit ni com alliance Declaration of Conformity DoC A DoC is our claim of compliance with the Council of the European Communities using the manufacturer s declaration of conformity This system affords the user protection for electronic compatibility EMC and product safety You can obtain the DoC for your product by visiting ni com hardref nsf National Instruments Corporation F 1 SCB 68 Shielded Connector Block User Manual Chapter F Technical Support and Professional Services e Calibration Certificate If your product supports calibration you can obtain the calibration certificate for your product at ni com calibration If you searched ni com and could not find the answers you need contact your local office or NI corporate headquarters P
18. for Special Functions R3 DACOOUT e WV e T Rc3 C AOGND e e Figure 5 3 Analog Output Channel Configuration Diagram for DACOOUT Conditioning PFIO TRIG1 Figure 5 4 illustrates the digital input channel configuration and Figure 5 5 shows the digital input channel configuration for PFIO TRIGI PFIO TRIG1 DGND Figure 5 4 Digital Input Channel Configuration Diagram PFIO TRIG1 AAN 9 RC1 DGND e Figure 5 5 Digital Input Channel Configuration Diagram for PFIO TRIG1 SCB 68 Shielded Connector Block User Manual 5 4 ni com Chapter 5 Adding Components for Special Functions Accuracy and Resolution Considerations When you measure voltage to subsequently measure current take the following steps to maximize measurement accuracy 1 Refer to the accuracy tables in Appendix A Specifications of the DAQ device user manual at ni com manuals 2 Use Equation 5 1 to determine the code width which is the smallest signal change that a system can detect 3 Divide code width by the resistor value to determine the minimum current value you can measure Code Width Si Pane 5 1 Gain x pResolution In Equation 5 1 range defines the values between and including the minimum and maximum voltages that the ADC can digitize For example the range is 20 when you measure a signal between 10 to 10 V Gain
19. modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks DAQCard National Instruments NI and ni com are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies Patents For patents covering National Instruments products refer to the appropriate location Help Patents in your software the patents txt file on your CD or ni com patents WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELE
20. place for each channel used When making thermocouple measurements with the SCB 68 the possible sources of error are compensation linearization measurement and thermocouple wire errors Compensation error can arise from two sources inaccuracy of the temperature sensor and temperature differences between the temperature sensor and the screw terminals The temperature sensor on the SCB 68 is specified to be accurate to 1 C You can minimize temperature differences between the temperature sensor and the screw terminals by keeping the SCB 68 away from drafts heaters and warm equipment Thermocouple output voltages are nonlinear with respect to temperature Conversion of the voltage output to temperature using either look up tables or polynomial approximations introduces linearization error The linearization error is dependent upon how closely the table or the polynomial approximates the true thermocouple output For example you can reduce the linearization error by using a higher degree polynomial Measurement error is the result of inaccuracies in the DAQ device These inaccuracies include gain and offset If the device is properly calibrated the offset error should be zeroed out The only remaining error is a gain error of 0 08 of full range If the input range is 10 V and the gain is 500 gain error contributes 0 0008 x 20 mV or 16 uV of error If the Seebeck coefficient of a thermocouple is 32 n V C this measurement error adds
21. safety A 3 support services F 1 to F 2 switch settings configuration and affected signals table 2 3 to 2 5 temperature sensor configuration 4 2 to 4 3 system integration support F 1 National Instruments Corporation l 7 Index T technical support and professional services F 1 to F 2 temperature sensor configuration 4 2 to 4 3 thermocouples 4 1 to 4 3 cold junction compensation 4 2 coloring of thermocouples table 4 1 maximum voltage level 4 2 open thermocouple detection 5 5 to 5 7 differential 5 6 single ended 5 6 sources of error 5 6 to 5 7 special considerations 4 3 switch settings and temperature sensor configuration 4 2 to 4 3 timing I O TIO devices quick reference label table 1 4 timing signal connections description 3 12 to 3 13 switch settings table 4 4 training support F 1 V voltage accuracy and resolution of voltage measurement 5 5 maximum working voltage specifications A 2 voltage attenuation 5 18 to 5 24 adding components analog output and digital input attenuators 5 22 differential input attenuators 5 21 single ended input attenuators 5 20 to 5 21 selecting components 5 20 accuracy considerations 5 20 SCB 68 Shielded Connector Block User Manual Index special considerations analog input 5 22 to 5 23 analog output 5 23 digital inputs 5 24 theory of operation 5 19 SCB 68 Shielded Connector Block User Manual 1 8 ni com
22. the output signal of the transducer SCB 68 Shielded Connector Block User Manual 5 18 ni com Chapter 5 Adding Components for Special Functions R4 e AWV et Vin R2 Vm e e Figure 5 19 Attenuating Voltage with a Voltage Divider Theory of Operation The voltage divider splits the input voltage V between two resistors R and R3 causing the voltage on each resistor to be noticeably lower than Vin Use Equation 5 12 to determine the V that the DAQ device measures V Yal Ra 5 12 m 7 us x 5 Use Equation 5 13 to determine the overall gain of a voltage divider circuit R R 5 13 The accuracy of Equation 5 13 depends on the tolerances of the resistors that you use UN Caution The SCB 68 is not designed for any input voltages greater than 42 V even if a user installed voltage divider reduces the voltage to within the input range of the DAQ device Input voltages greater than 42 V can damage the SCB 68 any devices connected to it and the host computer Overvoltage can also cause an electric shock hazard for the operator NI is not responsible for damage or injury resulting from such misuse National Instruments Corporation 5 19 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Selecting Components To set up the resistors complete the following steps 1 Select the value for R 10 KQ is recommended 2 Use Equation 5 12 to calculate
23. x im 1 SCB 68 Connector Blocks 4 100 Pin DAQ Device 2 68 Pin I O Connectors 3 SH1006868 Cable Assembly 5 100 Pin I O Connector Figure 1 3 Connecting a 100 Pin DAQ Device to Two SCB 68 Connector Blocks When you attach two SCB 68 devices to the SH1006868 cable one of the SCB 68 connector blocks has a full 68 pin I O connector pinout and the other SCB 68 connector block has an extended AI or extended digital pinout Each 68 pin end of the SH1006868 cable has a label that indicates which I O connector pinout is associated with that 68 pin I O connector Figure 1 4 shows the pin assignments for the I O connector on a 68 pin E Series device This connector is available when you use the SH68 68 EP or R6868 cable assemblies with an E Series DAQ device It is also one of two 68 pin connectors available when you use the SH1006868 cable assembly with a 100 pin E Series DAQ device National Instruments Corporation 1 7 SCB 68 Shielded Connector Block User Manual Chapter 1 Introduction ACH8 34 68 ACHO ACH1 33 67 AIGND AIGND 32 66 ACH9 ACH10 31 65 ACH2 ACH3 30 64 AIGND AIGND 29 63 ACH11 ACH4 28 62 AISENSE AIGND 27 61 ACH12 ACH13 26 60 ACH5 ACH6 25 59 AIGND AIGND 24 58 ACH14 ACH15 23 57 ACH7 DACOOUT 22 56 AIGND DAC1OUT 2
24. 1 55 AOGND EXTREF 20 54 AOGND2 DIO4 19 53 DGND DGND 18 52 DIOO DIO1 17 51 DIO5 DIO6 16 50 DGND DGND 15 49 DIO2 5V 14 48 DIO7 DGND 13 47 DIOS DGND 12 46 SCANCLK PFIO TRIG1 11 45 EXTSTROBE PFH TRIG2 10 44 DGND DGND 9 43 PFI2 CONVERT 5V 8 42 PFI3 GPCTR1_SOURCE DGND 7 41 PFI4 GPCTR1_GATE PFI5 UPDATE 6 40 GPCTR1_OUT PFI6 WFTRIG 5 39 DGND DGND 4 38 PFI7 STARTSCAN PFI9 GPCTRO_GATE 3 37 PFI8 GPCTRO_SOURCE GPCTRO OUT 2 36 DGND FREQ OUT 1 35 DGND 1 No connect on the DAQCard Al 16E 4 DAQCard Al 16XE 50 NI PCI 6023E NI PCI 6032E NI PCI 6033E and NI PCI 6034E 2 No connect on the DAQCard Al 16E 4 and DAQCard Al 16XE 50 3 No connect on the DAQCard Al 16E 4 DAQCard Al 16XE 50 DAQCard 6024E NI PCI 6023E NI PCI 6024E NI PXI 6030E NI PXI 6031E NI PCI 6032E NI PCI 6033E NI PCI 6034E NI PCI 6035E NI PCI 6036E PCI MIO 16XE 10 and PCI MIO 16XE 50 Figure 1 4 SCB 68 E Series I O Connector Pinout Full SCB 68 Shielded Connector Block User Manual 1 8 ni com Chapter 1 Introduction Figure 1 5 shows the pin assignments for the extended AI connector This pinout shows the other 68 pin connector when you use the SH1006868 cable assembly with an NI 6031E NI 6033E or NI 6071E ACH24 ACH17 ACH18 ACH27 ACH20 ACH21 ACH30 ACH23 ACH32 ACH41 ACH34 ACH35 AIGND ACH44 ACH37 ACH38 ACH47 ACH48 ACH49 ACH58 ACH51 ACH52 ACH61 A
25. 2 Differential Switch Configuration Special Considerations To connect a high value resistor between the positive input and 5V refer to the Accuracy and Resolution Considerations section of Chapter 5 Adding Components for Special Functions To reduce noise by connecting a lowpass filter to the analog inputs of the SCB 68 refer to the Lowpass Filtering section of Chapter 5 Adding Components for Special Functions National Instruments Corporation 4 3 SCB 68 Shielded Connector Block User Manual Adding Components for Special Functions This chapter describes how to condition signals by adding components to the open component locations of the SCB 68 To add components to these locations the DAQ device must support switch configurations 2 3 or 4 in Table 2 1 Switch Configurations and Affected Signals UN Caution Add components at your own risk The following signal conditioning applications are described in this chapter e Analog input Open thermocouple detection Lowpass filtering Measuring 4 20 mA current Voltage attenuation e Analog output Lowpass smoothing filter Voltage attenuation e Digital input Lowpass digital filter Voltage attenuation In addition to the applications described in this chapter many other types of signal conditioning can be built using the component pads and the general purpose breadboard area of the SCB 68 Refer to Appendix E Soldering and Desolde
26. B for one channel and pads G and D for the next channel You can build a differential analog input RC filter with pads F and E For TRIGI you can use pads R1 and RC1 For AO you can use R2 and RC2 for DACIOUT and you can use R3 and RC3 for DACOOUT National Instruments Corporation 5 11 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions For any type of lowpass filter use Equation 5 5 to determine the cut off frequency fe 1 5 5 2mRC oe fe Single Ended Lowpass Filter To build a single ended lowpass filter refer to Figure 5 12 Add the resistor to position B or D depending on the AI channel you are using Add the capacitor to position F or G depending on the AI channel you are using ACH CFG e Vin Paps Vin e e AIGND V Figure 5 12 SCB 68 Circuit Diagram for a Single Ended Lowpass Filter Differential Lowpass Filter To build a differential lowpass filter refer to Figure 5 13 Add the resistor to position E and the capacitor to position F ACH lt p CF e T Vin RE Vm e e ACH i8 Figure 5 13 SCB 68 Circuit Diagram for a Differential Lowpass Filter Analog Output and Digital Input Lowpass Filtering For DACOOUT add the resistor to position RC3 and the capacitor to position R3 For DACIOUT add the resistor to position RC2 and the capacitor to position R2 For TRIGI add the resistor to
27. CB 68 describes input modes and discusses noise considerations to help you acquire accurate signals Connecting Analog Input Signals The following sections describe how to connect signal sources for single ended or differential DIFF input mode On most devices you can software configure the DAQ device channels for two types of single ended connections nonreferenced single ended NRSE input mode and referenced single ended RSE mode RSE input mode is used for floating signal sources In this case the DAQ device provides the reference ground point for the external signal NRSE input mode is used for ground referenced signal sources In this case the external signal supplies its own reference ground point and the DAQ device should not supply one AA Note Some devices might only support one of the possible input modes Input Modes You can configure the DAQ device for one of three input modes NRSE RSE or DIFF The following sections discuss the use of single ended and differential measurements and considerations for measuring both floating and ground referenced signal sources On devices that support both single ended and DIFF input modes using DIFF input mode commits two channels ACH lt i gt and ACH lt i 8 gt to each signal Figure 3 1 summarizes the recommended input modes for both types of signal sources National Instruments Corporation 3 1 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals
28. CH54 ACH55 NC NC NC NC NC NC NC NC NC 34 68 33 67 32 66 31 65 30 64 29 63 28 62 27 61 26 60 25 59 24 58 23 57 22 56 21 55 20 54 19 53 18 52 17 51 16 50 15 49 14 48 13 47 12 46 11 45 10 44 43 42 41 40 39 38 37 36 NI V AJo oN oO o 35 NC No Connect ACH16 ACH25 ACH26 ACH19 ACH28 ACH29 ACH22 ACH31 ACH40 ACH33 ACH42 ACH43 AISENSE2 ACH36 ACH45 ACH46 ACH39 ACH56 ACH57 ACH50 ACH59 ACH60 ACH53 ACH62 ACH63 NC NC NC NC NC NC NC NC NC National Instruments Corporation Figure 1 5 SCB 68 E Series 1 0 Connector Pinout Extended Al 1 9 SCB 68 Shielded Connector Block User Manual Chapter 1 Introduction Figure 1 6 shows the pin assignments for the extended digital connector This pinout shows the other 68 pin connector when you use the SH1006868 cable assembly with an NI 6025E or the NI 6021E AT MIO 16DE 10 for ISA GND _ 34 68 PC6 33 67 PC5 32 66 GND 31 65 PC3 30 64 PC2 29 63 GND 28 62 PCO 27 61 PB7 26 60 GND 25 59 PBS 24 58 PB4 23 57 GND _ 22 56
29. CTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYST
30. DAQ SCB 68 68 Pin Shielded Connector Block User Manual Wy NATIONAL December 2002 Edition y INSTRUMENTS Part Number 320745B 01 Worldwide Technical Support and Product Information ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 683 0100 Worldwide Offices Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 00 20 Brazil 55 11 3262 3599 Canada Calgary 403 274 9391 Canada Montreal 514 288 5722 Canada Ottawa 613 233 5949 Canada Qu bec 514 694 8521 Canada Toronto 905 785 0085 China 86 21 6555 7838 Czech Republic 02 2423 5774 Denmark 45 76 26 00 Finland 09 725 725 11 France 01 48 14 24 24 Germany 089 741 31 30 Greece 01 42 96 427 Hong Kong 2645 3186 India 91 80 4190000 Israel 03 6393737 Italy 02 413091 Japan 03 5472 2970 Korea 02 3451 3400 Malaysia 603 9596711 Mexico 001 800 010 0793 Netherlands 0348 433466 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 22 3390 150 Portugal 210 311 210 Russia 095 238 7139 Singapore 65 6 226 5886 Slovenia 3 425 4200 South Africa 11 805 8197 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 For further support information refer to the Technical Support and Professional Services appendix To comment on the documentation send email to techpubs ni com 1994 2002 National Instruments Corporation All rights reserv
31. E Single Ended Connections for Grounded Signal Sources NRSE Input Mode eie eet ete recien koe ndo Connecting Analog Output Signals eese Connecting Digital Signals tices ttt dte aa a a aias Connecting Timing Signals eet ege prie tp ar ei aS Noise Considerations tacet eee vere esses y ota KN E aoe aee ends Chapter 4 Using Thermocouples Switch Settings and Temperature Sensor Configuration esses Special Considerations eissu pe tm tede teet e teet Chapter 5 Adding Components for Special Functions Channel Pad Configurations eese a A rennen emen rennen Conditioning Analog Input Channels eee Conditioning Analog Output Channels eee Conditioning PRIO TRIG 5 entree rtr tegens Accuracy and Resolution Considerations sese Open Thermocouple D tectiOh e ette tre mem ret tr e es Differential Open Thermocouple Detection see Single Ended Open Thermocouple Detection sess Sources OF ETTOE ge do eet tee tecto Eowpass Eiltertng eet DE On o ete eene Theory of Operation itle ne tec ean Gee One Pole Lowpass RC Filter neire es erene E E E eene Selecting Components eira a E ERE E E rte etude Adding Components re tite het Cae R e Single Ended Lowpass Filter esee Differential Lowpass Filter eese
32. EM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Compliance FFCC Canada Radio Frequency Interference Compliance Determining FCC Class The Federal Communications Commission FCC has rules to protect wireless communications from interference The FCC places digital electronics into two classes These classes are known as Class A for use in industrial commercial locations only or Class B for use in residential or commercial locations Depending on where it is operated this product could be subject to restrictions in the FCC rules In Canada the Department of Communications DOC of Industry Canada regulates wireless interference in much the same way Digital electronics emit weak signals during normal operation that can affect radio television or other wireless products By examining the product you purchased you can determine the FCC Class and therefore which of the two FCC DOC Warnings apply in the following sections Some products may not be labeled at all for FCC if so the reader should then assume these are Class A devices FCC Class A products only display a simple warning statement of one paragraph in length regarding interference and undesired operation Most of our products are FCC Class A The FCC rules have restrictions regarding the locations where FCC Class A products can be operated FCC Class B products display either a FCC ID code
33. LED x VVV DIO lt 4 7 gt 5o Lo gt TTL Signal gt DIO lt 0 3 gt 5 V VV Switch DGND 1 O Connector SCB 68 Figure 3 7 Digital I O Connections Connecting Timing Signals If you are using a 68 pin or 100 pin DAQ device all external control over device timing is routed through the programmable function input PFI lines lt 0 9 gt These PFI lines are bidirectional as outputs they are not programmable and reflect the state of many DAQ waveform generation and general purpose timing signals The remaining timing signals use five different dedicated outputs 3 Note For more information refer to the device user manual at ni com manuals for detailed signal description and connection information SCB 68 Shielded Connector Block User Manual 3 12 ni com Chapter 3 Connecting Signals All digital timing connections are referenced to DGND Figure 3 8 demonstrates how to connect two external timing signals to the PFI pins of a DAQ device PFIO PFI2 PFIO Source PFI2 Source DGND O XM OX l O Connector SCB 68 Figure 3 8 Timing 1 0 Connections Noise Considerations Environmental noise can seriously affect the measurement accuracy of your application if you do not take proper care when running signal
34. O O PUE o L MEG Doce Mot o Jes NATIONAL B 8 L Deo Ql o 34 INSTRUMENTS e Bou g R5 3 a ERI RE R6 P is P sacmeneun 12 2000000 ye Hd RETRY M Ro to 33600000000046 9 0900000 35 o5 0000000000 SECO lo LL 2 9 66 000000000013 0000000 2 N Rw u BUG 0000000000 9000000 36 A SJENUWILO S O 32000000000047 0000000 Jn z 9 8 rem 0000000000 0006000 o Pur eei 2 9 165 9999989388 14 9899998 42 Ie o D ee o 84 Fo 31600000000048 6600000 37 Sarah gp BO 0000000000 0000000 DdESWLo O am O 64 0000000000 15 9999009 4 fa 0000000000 T Osmi NIE o 300600000000049 9 6000009938 B 0000000000 0000000 B aO lo agere O 63 000600000016 0009009 5 t Rasa Oh 0000000000 0000000 3 eb a FSI O 29 0000000000 50 9999090 39 IE 0000000000 o0 OqSLoSO 8 O 62 0000000000 17 9999999 6 Q o piste 06000000000 tee Cle o 282252090222 51 Qu 2295595 40 Dg OO o 81 a loooo 00018 6oooooo 7 Cordero S ma 053 99955 9999999 41 Beato meum 0000000008 0000000 RC pdo gy Hd 60 000000000019 amp 1 8290000 la anna 0000000000 DERS j HH tA 26000000000053 0000000 Rasy pg ES 0000000000 90009000 g Oo mip O 159000000000020 6909000 7 n RIEL 0000000000 oome Olo Fo 256606006006 54 Jao Aco 43 o a DTE 0000000000 2 ZI ol BeOS p HL Fo 58 000000000021 oZ rots ECZ5TD g Me 0000000000 RC3 xol a
35. SIGNAL e 9er FACTORY DEFAULT SETTING i TEMP SENSOR DISABLED DAC4OUT 19 x A se TEMP SENSORAND Figure B 3 NI 671X 673X Devices SCB 68 Shielded Connector Block User Manual B 4 ni com Chapter B Quick Reference Labels SCB 68 Quick Reference Label S SERIES DEVICES Wy NATIONAL p gt INSTRUMENTS PIN SIGNAL 68 ACHO ACHO PIN SIGNAL PIN SIGNAL ACHOGND DGND FREQ_OUT ACH SCANCLK DGND 66 ACHI DGND GPCTRO OUT P N 182509B 01 ACH1GND DIO3 DGND PFI9 GPCTRO_GATE ACH2 DIO7 PFIB GPCTRO SOURCE S1 i i i ACH2GND DGND DGND sas H ACH3 DIO2 PFI7 STARTSCAN TEMP SENSOR DISABLED ACH3 fie Dos PFI6 WFTRIG ACCESSORY POWER ON ACH3GND DGND DGND DIO1 6l PFI5 UPDATE i sito 28 NC 51 GPCTRLOUT LLL seo 615 NC DGND 27 NC s2 Doo PFI4 GPCTR1_GATE TEMP SENSOR ENABLED ON DIFFERENTIAL CH 0 DIO4 8 5V FUSED ACCESSORY POWER ON E DGND PFIS GPCTR1 SOURCE o DGND i i sr a Prizconver sz PFH TRIG2 S5 S4 S3 DGND 68 GENERIC TERMINALS TEMP SENSOR AND PFIO TRIG1 56 NC 45 ACCESSORY POWER OFF Figure B 4 S Series Devices National Instruments Corporation B 5 SCB 68 Shielded Connector Block User Manual Chapter B Quick Reference Labels SCB 68 Quick Reference Label NI 660X DEVICES b f NATIONAL y INSTRUMENTS If using an NI 660X device with an optional SCB 68 shielded connector block accessory affix this label to the inside of the SCB 68 and set the
36. Screw Terminal XF1 Clip gt Eod pas ACC Not Powered R20 45V e NC Optional I O Pin 8 d ACC Powered R21 WV e 15 V DGND PREY Vo aad E DGND Screw Terminal La G2 e es S2 10 uF os E 10 uF 0 1 uF VO Pin 7 es MIO W W D Non MIO AIGND Screw Terminal NS NC l O Pin 56 wees MIO NV Figure D 1 5 V Power Supply National Instruments Corporation D 1 SCB 68 Shielded Connector Block User Manual Chapter D SCB 68 Circuit Diagrams 5V dE E Y R22 i WV R4 gt ACHO 8 Ui Screw Terminal CJC Not Used aw i rey AIGND User Configurable ACH S T 0 S5 I O Pin 68 ry CJC Used C3 Qi 0 1 uF R38 AI C5 1 uF 5V hv A 7 NY moa T WV ARAN P ACH8 booa M Screw Terminal ACH8 Vwi I O Pin 34 S4 i DIFF CJC sH y Rc13 AIGND W User Configurable Figure D 2 Cold Junction Compensation Circuitry PFIO TRIG1 R1 I O Pin 11 e AAA gt PFIO TRIG1 Screw Terminal RC1 DGND een 44 e 9 DGND Screw Terminal SCB 68 Shielded Connector Block User Manual Figure D 3 Digital Trigger Circuitry D 2 ni com Chapter D SCB 68 Circuit Diagrams DACOOUT R3 I O Pin 22 AWS RCS AOGND I O Pin 55 DAC1OUT R2 I O Pin 21 WS RC2 Z AOGND I O Pin 54 b gt DACOOUT Screw Terminal
37. User Manual B 6 RG PFI_2 ni com Chapter B Quick Reference Labels SCB 68 Quick Reference Label NI 653X DEVICES WwW NATIONAL y INSTRUMENTS If using an NI 653X with an optional SCB 68 shielded connector block accessory affix this label to the inside of the SCB 68 and set the switches as shown below P N 185754A 01 Rev 2 SET SWITCHES AS FOLLOWS FOR THE NI 653X mM crm L MON S National Instruments Corporation PIN SIGNAL PIN SIGNAL PIN SIGNAL 5V RGND REQ1 GND ACK1 STARTTRIG1 GND STOPTRIG1 DPULL PCLK1 GND PCLK2 CPULL STOPTRIG2 GND ACK2 STARTTRIG2 GND REQ2 RGND DIOAO DIOA1 GND Figure B 6 NI 653X Devices B 7 DIOA2 SCB 68 Shielded Connector Block User Manual Chapter B Quick Reference Labels SCB 68 Quick Reference Label NM NI 7811R 7831R DEVICES INSTRUMENTS PIN MIO PIN MIO DIO12 DIO138 DIO14 DIO15 AOGND7 AO7 AOGND6 AO6 AOGNDS5 AO5 AOGND4 AO4 1 THE MIO COLUMN CORRESPONDS AOGND3 TO THE MIO CONNECTOR ON THE NI 7831R AND THE DIO COLUMN CORRESPONDS TO THE DIO AO3 CONNECTORS ON THE NI 7811R 7831R AOGND2 NC No Connect AO2 SET SWITCHES IN AGNES THIS CONFIGURATION TO USE THE SCB 68 AO1 WITH THE NI 7811R 7831R AOGNDO AOO Mp S2 NC S584 S3 AISENSE
38. al mode digital input output direct memory access a method by which data can be transferred to from computer memory from to a device or memory on the bus while the processor does something else DMA is the fastest method of transferring data to from computer memory Declaration of Conformity SCB 68 Shielded Connector Block User Manual Glossary E EXTREF EXTSTROBE EXTTRIG F FREQ OUT ft G gain GATE GPCTR GPCTRO GATE GPCTR1_GATE GPCTRO_OUT GPCTR1_OUT GPCTRO_SOURCE GPCTR1_SOURCE amp rms H Hz external reference signal external strobe signal external trigger signal frequency output signal feet the factor by which a signal is amplified often expressed in dB gate signal general purpose counter general purpose counter 0 gate signal general purpose counter 1 gate signal general purpose counter 0 output signal general purpose counter output signal general purpose counter 0 clock source signal general purpose counter clock source signal level of random vibration hertz SCB 68 Shielded Connector Block User Manual G 4 ni com L lowpass filter LSB MB MIO NC NI DAQ noise NRSE National Instruments Corporation G 5 Glossary input output the transfer of data to from a computer system involving communications channels operator interface devices and or data acquisition and control interfaces current output high current output low a filter t
39. artment of Communications This Class B digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe B respecte toutes les exigences du R glement sur le mat riel brouilleur du Canada Compliance to EU Directives Readers in the European Union EU must refer to the Manufacturer s Declaration of Conformity DoC for information pertaining to the CE Marking compliance scheme The Manufacturer includes a DoC for most every hardware product except for those bought for OEMs if also available from an original manufacturer that also markets in the EU or where compliance is not required as for electrically benign apparatus or cables To obtain the DoC for this product click Declaration of Conformity at ni com hardref nsf This Web site lists the DoCs by product family Select the appropriate product family followed by your product and a link to the DoC appears in Adobe Acrobat format Click the Acrobat icon to download or read the DoC The CE Marking Declaration of Conformity will contain important supplementary information and instructions for the user or installer Contents About This Manual Conventions 2 sim ee Hii neo M Opus xi NL Documentation 4 9 30 eal nien am E etii xii Chapter 1 Introduction What You Need to Get Started sse eene nnne 1 1 Quick Reference Label cccccccccccccssssccceeesssceecceeessscecccesesssseececseseee
40. cecessnseeeeeeesseeeeees 1 2 Installing Cables ite ER setae CES RERM tebe ceeteseadeccest oes 1 5 Using 68 Pin Cables eet tete tet e ee ei 1 5 Using 100 Pin Cables 2 3 ome dieere tete eret rrt 1 6 Configuring the SCB 068 srein tariei ee epe re Ret dg 1 11 Safety Information ette RU ERE Ie ER ERUNT NR e eds 1 11 Chapter 2 Parts Locator and Wiring Guide Switch Configuration oi re p ee ER t Te RR OE ap CREER A cates EVER RER E PEL IORES 2 3 Chapter 3 Connecting Signals Connecting Analog Input Signals essere enne 3 1 Input Modes Ram eee pae eee Soa eet 3 1 Nonreferenced or Floating Signal Sources ee 3 3 Differential Inputs entrer etie 3 3 Smgle Ended Inputs 2 4t etat RR 3 3 Ground Referenced Signal Sources eee 3 4 Differential Inputs 23 eene metr epe 3 4 Single Ended Inputs eese 3 4 Differential Connection Considerations DIFF Input Mode 3 5 Differential Connections for Ground Referenced Signal Sources 3 6 Differential Connections for Nonreferenced or Floating Signal Sources see 3 7 Using Bias Resistors eere 3 7 National Instruments Corporation vii SCB 68 Shielded Connector Block User Manual Contents Single Ended Connection Considerations esse Single Ended Connections for Floating Signal Sources RSE Input Mode eui rA rete EH
41. cessary Connect the wires to the screw terminals by stripping off 0 25 in of the insulation inserting the wires into the green terminals and tightening the screws Reinstall the strain relief bar if you removed it and tighten the strain relief screws Close the top cover Reinsert the shielding screws to ensure proper shielding You can now connect the SCB 68 to the 68 pin I O connector Switch Configuration The SCB 68 has five switches that must be properly configured to use the SCB 68 with the DAQ device Table 2 1 illustrates the available switch configurations and the affected signals for each switch setting Refer to Table 2 1 to determine the switch setting that applies to your application and then refer to the following sections for more information on specific types of signals National Instruments Corporation 2 3 SCB 68 Shielded Connector Block User Manual Chapter 2 Parts Locator and Wiring Guide Table 2 1 Switch Configurations and Affected Signals Switch Setting Applicable Signals Temperature Sensor S5 84 S3 OJO Signal Conditioning Circuitry Power Off S1 S2 Direct feedthrough with temperature sensor disabled and accessory power disabled Analog input analog output digital I O and timing I O Temperature Sensor S5 S4 S3 OlOlO Signal Conditioning Circuitry Power On NEB Temperature sensor disabled and accessory power enabled
42. coupling between lines separate them by a reasonable distance if they run in parallel or run the lines at right angles to each other Do not run signal lines through conduits that also contain power lines Protect signal lines from magnetic fields caused by electric motors welding equipment breakers or transformers by running them through special metal conduits For information about minimizing noise in your application refer to the NI Developer Zone tutorial Field Wiring and Noise Considerations for Analog Signals located at ni com zone SCB 68 Shielded Connector Block User Manual 3 14 ni com Using Thermocouples This chapter describes how to take thermocouple measurements using the SCB 68 A thermocouple is created when two dissimilar metals touch and the contact produces a small voltage that changes as a function of temperature By measuring the voltage of a thermocouple you can determine temperature using a nonlinear equation that is unique to each thermocouple type Thermocouple types are designated by capital letters that indicate their composition according to the American National Standards Institute ANSI conventions To determine the type of thermocouple that you are using refer to Table 4 1 For more information on the theory of operation of thermocouples refer to the NI Developer Zone tutorial Measuring Temperature with Thermocouples at ni com zone Table 4 1 Thermocouple Coloring
43. d and the signal ground appears as a common mode signal at both the positive and negative inputs of the instrumentation amplifier and this difference is rejected by the amplifier If the input circuitry of a DAQ device were referenced to ground in this situation as in the RSE input mode this difference in ground potentials would appear as an error in the measured voltage National Instruments Corporation 3 9 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals Figure 3 5 shows how to connect a grounded signal source to a channel on the DAQ device configured for NRSE input mode Instrumentation Ground Amplifier Referenced Signal Vs Source a Common Mode Vom Noise _ AISENSE Measured Voltage AIGND and Ground Potential 77 I O Connector Measurement Device Configured in NRSE Input Mode Not all devices support NRSE input mode Figure 3 5 Single Ended Input Connections for Ground Referenced Signals Connecting Analog Output Signals When using the SCB 68 with a 68 pin or 100 pin DAQ device the AO signals are DACOOUT DACIOUT EXTREF and AOGND DACOOUT is the voltage output channel for AO channel 0 DACIOUT is the voltage output channel for AO channel 1 EXTREF is the external reference input for both AO channels AOGND is the ground reference signal for both AO channels and the external reference signal 3 Note For more in
44. d the stopband a ripple in the passband and a stopband with a finite attenuation gain Real filters have some nonlinearity in their phase response causing signals at higher frequencies to be delayed by longer times than signals at lower frequencies and resulting in an overall shape distortion of the signal For example when the square wave shown in Figure 5 8 enters a filter an ideal filter smooths the edges of the input whereas a real filter causes some SCB 68 Shielded Connector Block User Manual 5 8 ni com Chapter 5 Adding Components for Special Functions ringing in the signal as the higher frequency components of the signal are delayed Volts V Time t Figure 5 8 Square Wave Input Signal Figures 5 9 and 5 10 show the difference in response to a square wave between an ideal and a real filter respectively Volts V Time t Figure 5 9 Response of an Ideal Filter to a Square Wave Input Signal National Instruments Corporation 5 9 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Volts V Time t Figure 5 10 Response of a Real Filter to a Square Wave Input Signal One Pole Lowpass RC Filter Figure 5 11 shows the transfer function of a simple series circuit consisting of a resistor R and capacitor C when the voltage across R is assumed to be the output voltage Vm C e V
45. device Using 68 Pin Cables Table 1 1 lists the 68 pin cable assemblies that can connect the SCB 68 to a 68 pin DAQ device Each end of these 68 pin cables has a 68 pin I O connector that you can connect to the SCB 68 and to the 68 pin DAQ device In this configuration the I O connector pinout on the DAQ device determines the I O connector pinout on the SCB 68 National Instruments Corporation 1 5 SCB 68 Shielded Connector Block User Manual Chapter 1 Introduction Figure 1 2 shows how to use a 68 pin cable to connect the SCB 68 to a 68 pin DAQ device 7 on 1 68 Pin Cable Assembly 4 68 Pin I O Connector 2 68 Pin DAQ Device 5 SCB 68 Connector Block 3 68 Pin I O Connector Figure 1 2 Connecting a 68 Pin DAQ Device to an SCB 68 Using 100 Pin Cables You can use the SH1006868 cable assembly to connect two SCB 68 connector blocks to a 100 pin DAQ device The SH1006868 is Y shaped with a 100 pin male connector on one end and two 68 pin female connectors on the opposite end The DAQ device connects to the 100 pin cable connector and an SCB 68 can connect to each 68 pin cable connector Figure 1 3 shows how use the SH1006868 to cable a 100 pin DAQ device to two SCB 68 devices SCB 68 Shielded Connector Block User Manual 1 6 ni com Chapter 1 Introduction P EE 0 A S o
46. ed Important Information Warranty The SCB 68 is warranted against defects in materials and workmanship for a period of one year from the date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instrume
47. ed to it Figure 5 15 shows the output of a lowpass filter when a stairstep like signal is the input SCB 68 Shielded Connector Block User Manual 5 14 ni com Chapter 5 Adding Components for Special Functions Volts V Time t Figure 5 15 Lowpass Filtering of AO Signals Special Consideration for Digital Trigger Input Signals Lowpass filters can function as debouncing filters to smooth noise on digital trigger input signals thus enabling the trigger detection circuitry of the DAQ device to understand the signal as a valid digital trigger A TTL Logic High Volts V TTL Logic Time t Figure 5 16 Digital Trigger Input Signal with a High Frequency Component National Instruments Corporation 5 15 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Apply a lowpass filter to the signal to remove the high frequency component for a cleaner digital signal as Figure 5 17 shows Volts V Time t Figure 5 17 Lowpass Filtering of Digital Trigger Input Signals 3 Note Due to the filter order the digital trigger input signal is delayed for a specific amount of time before the DAQ device senses the signal at the trigger input Measuring a 4 to 20 mA Current Since DAQ devices cannot directly measure current this section describes how to add components for measuring current when transistors output a current value
48. eedthrough only for PCI PXI CompactPCI R6868 Other Devices NI 250X SH68 68 Direct feedthrough only for PXI CompactPCI NI 4350 for PCMCIA SH68 68 Not recommended for use with the DAQCard 4350 SCB 68 NI 4350 for USB T To maximize the available features NI recommends using this DAQ device with the CB 68T TBX 68 or TBX 68T terminal blocks NI 4351 SH68 68 Not recommended for use with the for PCIPXI CompactPCI SCB 68 To maximize the available features NI recommends using this DAQ device with the CB 68T TBX 68 or TBX 68T terminal blocks NI 445X for PCI SHC50 68 Direct feedthrough only NI 455X for PCI SHC50 68 Direct feedthrough only NI 5411 SHC50 68 Direct feedthrough only for PCI PXI CompactPCI NI 5431 SHC50 68 Direct feedthrough only for PCI PXI CompactPCI SCB 68 Shielded Connector Block User Manual 1 4 ni com Chapter 1 Introduction 1 Quick Reference Label 4 Lock Washers 8 Strain Relief Bars 2 Cover 5 Shielding Screws 9 Strain Relief Screws 3 68 Pin Connector 68 Pin I O Connector 10 Circuit Card Assembly 6 Screws 7 Base Figure 1 1 SCB 68 Parts Locator Diagram Installing Cables The following sections describe how to cable one or more SCB 68 connector blocks to a DAQ device using 68 pin or 100 pin cables 3 Note For the I O connector pinout of the DAQ device refer to the device user manual at ni com manuals or to the quick reference label provided with the DAQ
49. elded Connector Block User Manual Chapter 5 Adding Components for Special Functions Adding Components IN Caution Do not exceed 10 V at the analog inputs NI is not liable for any device damage or personal injury resulting from improper connections You can build a one resistor circuit for measuring current at the single ended or differential inputs of the SCB 68 Single Ended Inputs To build a one resistor circuit that measures current at the single ended analog inputs of the SCB 68 add the resistor to position B or D depending on the channel being used Leave the jumpers in place for channel positions F and G respectively Calculate the current according to Equation 5 9 or 5 10 V f 5 9 Rg V 12 2 5 10 Rg Differential Inputs To build a one resistor circuit that measures current at the differential inputs of the SCB 68 add the resistor to position E for each differential channel pair that is used Leave the jumpers in place for positions F and G Calculate the current according to Equation 5 11 5 11 Attenuating Voltage This section describes how to add components for attenuating or decreasing the amplitude of a voltage signal Transducers can output more than 10 Vpc per channel but DAQ devices cannot read more than 10 Vpc per input channel Therefore you must attenuate output signals from the transducer to fit within the DAQ device specifications Figure 5 19 shows how to use a voltage divider to attenuate
50. ely to remain within the common mode signal range of the PGIA and the PGIA saturates causing erroneous readings You must reference the source to the respective channel ground National Instruments Corporation 3 7 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals Common mode rejection might be improved by using another bias resistor between ACH or ACH lt i gt and AIGND This connection creates a slight measurement error caused by the voltage divider formed with the output impedance of the floating source but it also gives a more balanced input for better common mode rejection Single Ended Connection Considerations A single ended connection is one in which the DAQ device AI signal is referenced to a ground that can be shared with other input signals The input signal is tied to the positive input of the instrumentation amplifier and the ground is tied to the negative input of the instrumentation amplifier You can use single ended input connections for input signals that meet the following conditions e The input signal is high level greater than 1 V e The leads connecting the signal to the DAQ device are less than 10 ft 3 m e The input signal can share a common reference point with other signals DIFF input connections are recommended for greater signal integrity for any input signal that does not meet the preceding conditions In single ended modes more electrostatic and magnetic noise c
51. es from screw terminals Remove the device mount screws and the 68 pin connector screws 6 Tilt the SCB 68 up and pull it out To reinstall the SCB 68 reverse the order of the steps The SCB 68 ships with wire jumpers in the F and G positions as Figure 2 1 SCB 68 Printed Circuit Diagram shows You must remove the wire jumpers to use the positions Use a low wattage soldering iron 20 to 30 W when soldering to the SCB 68 To desolder on the SCB 68 vacuum type tools work best Be careful to avoid damaging the component pads when desoldering Use only rosin core electronic grade solder because acid core solder damages the printed circuit device and components SCB 68 Shielded Connector Block User Manual E 2 ni com Technical Support and Professional Services Visit the following sections of the National Instruments Web site at ni com for technical support and professional services e Support Online technical support resources include the following Self Help Resources For immediate answers and solutions visit our extensive library of technical support resources available in English Japanese and Spanish at ni com support These resources are available for most products at no cost to registered users and include software drivers and updates a KnowledgeBase product manuals step by step troubleshooting wizards hardware schematics and conformity documentation example code tutorials and application notes instrument
52. formation refer to the device user manual at ni com manuals for detailed signal connection information for AO signals SCB 68 Shielded Connector Block User Manual 3 10 ni com Chapter 3 Connecting Signals Figure 3 6 shows how to make AO connections and the external reference connection to the SCB 68 and the DAQ device to EXTREF External m DACOOUT Reference V Signal ref optional _ VOUT 0 Load AOGND Load o DAC1OUT SCB 68 Figure 3 6 Connecting AO Signals Connecting Digital Signals When using the SCB 68 with a 68 pin or 100 pin DAQ device the DIO signals are DIO lt 0 7 gt and DGND DIO lt 0 7 gt are the eight single ended DIO lines and DGND is the ground reference You can program all lines individually to be inputs or outputs 3 Note For more information refer to the device user manual at ni com manuals for detailed signal description and connection information Figure 3 7 illustrates several common DIO applications and signal connections Digital input applications include receiving TTL signals and sensing external device states such as the state of the switch shown in Figure 3 7 Digital output applications include sending TTL signals and driving external devices such as the LED shown in Figure 3 7 National Instruments Corporation 3 11 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals 45V PA
53. gle ended lowpass filter 5 12 applications 5 13 to 5 14 antialiasing filtering 5 13 to 5 14 noise filtering 5 13 Bode Plots for ideal and real filters figures 5 8 one pole lowpass RC filter 5 10 to 5 11 selecting components 5 11 special considerations National Instruments Corporation Index analog input channels 5 14 analog output channels 5 14 to 5 15 digital trigger input signals 5 15 to 5 16 square wave input signal entry into filters figure 5 9 response of ideal filter figure 5 9 response of real filter figure 5 10 theory of operation 5 7 to 5 10 manual See documentation maximum working voltage specifications A 2 Measurement amp Automation Explorer MAX 1 11 measuring 4 20 mA current 5 16 to 5 18 adding components differential inputs 5 18 single ended inputs 5 18 selecting resistor 5 17 theory of operation 5 16 to 5 17 NI 653X devices quick reference label table 1 3 B 7 NI 660X devices quick reference label table 1 4 B 6 NI 670X devices quick reference label table 1 3 B 3 NI 671X 673X devices quick reference label table 1 3 B 4 NI 7811R 7831R devices quick reference label table B 8 noise lowpass filtering 5 13 minimizing environmental noise 3 13 to 3 14 recommendations for signal connections 3 14 SCB 68 Shielded Connector Block User Manual Index nonreferenced or floating signal sources bias resistors 3 7 description 3 3 de
54. hat are compatible with the SCB 68 National Instruments Corporation B 1 SCB 68 Shielded Connector Block User Manual Chapter B Quick Reference Labels SCB 68 Quick Reference Label E SERIES DEVICES b f NATIONAL y INSTRUMENTS P N 182509B 01 FACTORY DEFAULT SETTING A I I s m S5 S4 S3 TEMP SENSOR DISABLED ACCESSORY POWER ON sp m sU m S5 S4 S3 TEMP SENSOR ENABLED ON SINGLE ENDED CH 0 ACCESSORY POWER ON sil se T S5 S4 S3 TEMP SENSOR ENABLED ON DIFFERENTIAL CH 0 ACCESSORY POWER ON DE S5 S4 S3 68 GENERIC TERMINALS TEMP SENSOR AND ACCESSORY POWER OFF PIN SIGNAL f acho ENIM eo wee SCB 68 Shielded Connector Block User Manual PIN SIGNAL PIN SIGNAL Fe o s ewm s oes s wmm s o Figure B 1 E Series Devices B 2 ni com Chapter B SCB 68 Quick Reference Label NI 670X DEVICES NATIONAL INSTRUMENTS NO CONNECT ON THE NI 6703 AMY zem S5 S4 S3 68 GENERIC TERMINALS TEMP SENSOR AND ACCESSORY POWER OFF PIN SIGNAL e reno e vom e vors National Instruments Corporation B 3 PIN SIGNAL PIN SIGNAL ef 39 sf 3 09 n Figure B 2 NI 670X Devices SCB 68 Shielded Connector Block User Manual Quick Reference Labels Chapter B Quick Reference Labels SCB 68 Quick Reference Label NI 671X 673X DEVICES Ponte INSTRUMENTS PIN SIGNAL PIN SIGNAL PIN
55. hat passes low frequencies least significant bit meter megabytes of memory multifunction I O normally closed or not connected NI driver software for DAQ hardware an undesirable electrical signal noise comes from external sources such as the AC power line motors generators transformers fluorescent lights CRT displays computers electrical storms welders radio transmitters and internal sources such as semiconductors resistors and capacitors Noise corrupts signals you are trying to send or receive nonreferenced single ended mode all measurements are made with respect to a common NRSE measurement system reference but the voltage at this reference can vary with respect to the measurement system ground SCB 68 Shielded Connector Block User Manual Glossary Nyquist frequency 0 OUT PCI PFI PFIO TRIGI PFII TRIG2 PFI2 CONVERT PFI3 GPCTRI SOURCE PFI4 GPCTR1_GATE PFIS UPDATE PFI6 WFTRIG PFI7 STARTSCAN PFI8 GPCTRO_ SOURCE PFI9 GPCTRO_GATE PGIA port SCB 68 Shielded Connector Block User Manual G 6 a frequency that is half of the sampling frequency output pin a counter output pin where the counter can generate various TTL pulse waveforms Peripheral Component Interconnect a high performance expansion bus architecture originally developed by Intel to replace ISA and EISA It is achieving widespread acceptance as a standard for PCs and work stations it offers a theoretical maximu
56. hift that is linear with respect to frequency This linear phase shift delays signal components of all frequencies by a constant time independent of frequency thereby preserving the overall shape of the signal In practice lowpass filters subject input signals to a mathematical transfer function that approximates the characteristics of an ideal filter By analyzing the Bode Plot or the plot that represents the transfer function you can determine the filter characteristics Figures 5 6 and 5 7 show the Bode Plots for the ideal filter and the real filter respectively and indicate the attenuation of each transfer function National Instruments Corporation 5 7 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Passband Gain Stopband fc Log Frequency Figure 5 6 Transfer Function Attenuation for an Ideal Filter Gain Passband Stopband Transition p Region t gt Log Frequency Figure 5 7 Transfer Function Attenuation for a Real Filter The cut off frequency f is defined as the frequency beyond which the gain drops 3 dB Figure 5 6 shows how an ideal filter causes the gain to drop to zero for all frequencies greater than f Thus f does not pass through the filter to its output Instead of having a gain of absolute zero for frequencies greater than f the real filter has a transition region between the passband an
57. hone numbers for our worldwide offices are listed at the front of this manual You also can visit the Worldwide Offices section of ni com niglobal to access the branch office Web sites which provide up to date contact information support phone numbers email addresses and current events SCB 68 Shielded Connector Block User Manual F 2 ni com Glossary Prefix Meanings Value p pico 10 2 n nano 10 9 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 Numbers Symbols degrees gt greater than lt less than or equal to 2 greater than or equal to less than negative of or minus Q ohms per percent plus or minus positive of or plus National Instruments Corporation G 1 SCB 68 Shielded Connector Block User Manual Glossary 45V A D AC ACH ADC Al AIGND AISENSE AO AOGND ASIC attenuate AWG C CH square root of 5 VDC source signal amperes analog to digital alternating current analog input channel signal analog to digital converter an electronic device often an integrated circuit that converts an analog voltage to a digital number analog input analog input ground signal analog input sense signal analog output analog output ground signal Application Specific Integrated Circuit a proprietary semiconductor component designed and manufactured to perform a set of specific functi
58. in R E Vin e Figure 5 11 Transfer Function of a Simple Series Circuit The transfer function is a mathematical representation of a one pole lowpass filter with a time constant of 1 2nRC as follows G 5 MS IPORO o3 SCB 68 Shielded Connector Block User Manual 5 10 ni com Chapter 5 Adding Components for Special Functions Use Equation 5 3 to design a lowpass filter for a simple resistor and capacitor circuit where the values of the resistor and capacitor alone determine f In this equation G is the DC gain and s represents the frequency domain Selecting Components To determine the value of the components in the circuit fix R 10 kQ is reasonable and isolate C from Equation 5 3 as follows zu 1 2nRf 5 4 The cut off frequency in Equation 5 4 is f For best results choose a resistor that has the following characteristics e Low wattage of approximately 1 8 W e Precision of at least 5 e Temperature stability e Tolerance of 5 e AXL package suggested e Carbon or metal film suggested Choose a capacitor that has the following suggested characteristics e AXL or RDL package e Tolerance of 20 e Maximum voltage of at least 25 V Adding Components Using the circuit shown in Figure 5 11 you can use a two component circuit to build a simple RC filter with analog input analog output or digital input You can build a single ended analog input RC filter with pads F and
59. ing started 1 1 to 1 2 resolution and accuracy of voltage measurement 5 5 RSE referenced single ended input See single ended connections S S series devices quick reference label table 1 4 B 5 safety information 1 11 to 1 13 safety specifications A 3 SCB 68 See also installation configuration switch configuration 1 11 using Measurement amp Automation Explorer MAX 1 11 overview 1 1 parts locator diagram figure 1 5 2 2 quick reference label B 1 to B 8 quick reference label table 1 2 to 1 4 requirements for getting started 1 1 to 1 2 ni com safety information 1 11 to 1 13 specifications A 1 to A 3 SCB 68 E Series I O Connector pinout extended AI figure 1 9 extended digital figure 1 10 full figure 1 8 signal connections See connecting signals single ended connections description 3 8 grounded signal sources NRSE input mode 3 4 to 3 5 3 9 to 3 10 input attenuators 5 20 to 5 21 lowpass filter 5 12 measuring 4 20 mA current 5 18 nonreferenced or floating signal sources RSE input mode 3 3 3 9 open thermocouple detection 5 6 recommended input modes figure 3 2 switch configuration for temperature sensor figure 4 3 when to use 3 8 soldering and desoldering E 1 to E 2 specifications A 1 to A 3 analog input A 1 CE compliance A 3 electromagnetic compatibility A 3 environmental A 2 fuse A 1 to A 2 maximum working voltage A 2 physical A 2 power requirement A 1
60. inputs 3 4 3 6 adding components 5 11 to 5 12 single ended inputs 3 4 to 3 5 3 9 to 3 10 applications 5 13 to 5 14 one pole lowpass RC filter input modes 5 10 to 5 11 recommended input modes selecting components 5 11 figure 3 2 special considerations types of 3 1 analog input channels 5 14 nonreferenced or floating signal sources analog output channels So 5 14 to 5 15 description 3 3 digital trigger input signals differential inputs 3 3 5 15 to 5 16 TOS theory of operation 5 7 to 5 10 engi enned pnts 72 28 measuring 4 20 mA current 5 16 to 5 18 single ended connections adding components description 3 8 differential inputs 5 18 floating signal sources RSE single ended inputs 5 18 configuration 3 3 3 9 selecting resistor 5 17 grounded signal sources NRSE theory of operation 5 16 to 5 17 FOBDEUIAROU S l0 35 i 3 9 to 3 10 open thermocouple detection 5 5 to 5 7 analog output signals 3 10 to 3 11 differential 5 6 digital signals 3 11 to 3 12 single ended 5 6 installation procedure 2 3 sources of error 5 6 to 5 7 noise considerations 3 13 to 3 14 configuration timing signals 3 12 to 3 13 quick reference label B 1 to B 8 2 eir tel Gables oto conventions used in manual xi um im AE E el table current 4 20 mA measuring 5 16 to 5 18 switch configuration 2 3 to 2 5 i adding components using Measurement amp Automation Explorer MAX 1 11 didcren
61. instrumentation amplifier and its reference signal or return is tied to the negative input of the instrumentation amplifier On DAQ devices that support both single ended and DIFF input modes using DIFF input mode commits two channels ACH lt i gt and ACH lt i 8 gt to each signal You should use differential input connections for any channel that meets any of the following conditions e The input signal is low level less than 1 V e The leads connecting the signal to the DAQ device are longer than 10 ft 3 m e The input signal requires a separate ground reference point or return signal e The signal leads travel through noisy environments Differential signal connections reduce noise pickup and increase common mode noise rejection Differential signal connections also allow input signals to float within the common mode limits of the instrumentation amplifier National Instruments Corporation 3 5 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals Differential Connections for Ground Referenced Signal Sources Figure 3 2 shows how to connect a ground referenced signal source to a channel on the DAQ device configured in DIFF input mode Ground Referenced Signal Source E ACH or ACH lt amp Instrumentation Amplifier PGIA Measured Voltage ACH or ACH lt i 8 gt Common Mode Noise and V Ground Potential I O Connector
62. ions for Digital Inputs If you use the Vi voltage of Figure 5 20 to feed TTL signals you must calculate V so that the voltage drop on R does not exceed 5 V UN Caution A voltage drop exceeding 5 V on R can damage the internal circuitry of the DAQ device NI is not liable for any device damage or personal injury resulting from improper use of the SCB 68 and the DAQ device SCB 68 Shielded Connector Block User Manual 5 24 ni com Specifications This appendix lists the SCB 68 specifications These ratings are typical at 25 C unless otherwise stated Analog Input Number of channels 68 pin DAQ devices Eight differential 16 single ended 100 pin DAQ devices 32 differential 64 single ended Temperature sensor ACCULACY V re pole 1 0 C over a 0 to 110 C range Output e Uere pu 10 mV C Power Requirement Power consumption at 5 VDC 5 Typical ett oves 1 mA with no signal conditioning installed Maximum seseeeeeeere 800 mA from host computer hy Note The power specifications pertain to the power supply of the host computer when using internal power or to the external supply connected at the 5 V screw terminal when using external power The maximum power consumption of the SCB 68 is a function of the signal conditioning components installed and any circuits constructed on the general purpose breadboard area If the SCB 68 is powered from the host compute
63. l equipment for measurement control and laboratory use e EC 61010 1 EN 61010 1 e UL23III 1 e CAN CSA C222 No 1010 1 hy Note For UL and other safety certifications refer to the product label or to ni com Electromagnetic Compatibility EMISSIONS 5 ct eret erect lade EN 55011 Class A at 10m FCC Part 15A above 1 GHz IMMUNI ei rrr eem EN 61326 1 1997 A1 1998 Table 1 EMC IEMIL tite exe gene CE C Tick and FCC Part 15 Class A Compliant 3 Note For EMC compliance you must operate this device with shielded cabling CE Compliance This product meets the essential requirements of applicable European Directives as amended for CE Marking as follows Low Voltage Directive safety 73 23 EEC Electromagnetic Compatibility Directive EMC sese 89 336 EEC B Note Refer to the Declaration of Conformity DoC for this product for any additional regulatory compliance information To obtain the DoC for this product click Declaration of Conformity at ni com hardref nsf This Web site lists the DoCs by product family Select the appropriate product family followed by your product and a link to the DoC appears in Adobe Acrobat format Click the Acrobat icon to download or read the DoC National Instruments Corporation A 3 SCB 68 Shielded Connector Block User Manual Quick Reference Labels This appendix shows the pinouts that appear on the quick reference labels for the DAQ devices t
64. le 5 2 to 5 3 configuration diagram figure 5 2 analog output channels 5 3 to 5 4 component locations table 5 3 configuration diagram figure 5 3 DACOOUT configuration diagram figure 5 4 PFIO TRIGI figure 5 4 circuit diagrams 5 V power supply figure D 1 analog output circuitry figure D 3 cold junction compensation circuitry figure D 2 digital trigger circuitry figure D 2 cold junction compensation CJC circuitry diagram figure D 2 thermocouple measurements 4 2 colors of thermocouples table 4 1 components adding for special functions 5 1 to 5 24 accuracy and resolution considerations 5 5 attenuating voltage 5 18 to 5 24 adding components analog output and digital input attenuators 5 22 differential input attenuators 5 21 single ended input attenuators 5 20 to 5 21 ni com Index selecting components 5 20 connecting signals 3 1 to 3 14 accuracy considerations 5 20 analog input signals 3 1 to 3 10 special considerations differential connections DIFF input analog input 5 22 to 5 23 mode analog output 5 23 description 3 5 digital inputs 5 24 ground referenced signal theory of operation 5 19 sources 3 4 3 6 channel pad configurations 5 2 to 5 4 nonreferenced or floating signal analog input channels 5 2 to 5 3 sources 3 3 3 7 to 3 8 analog output channels 5 3 to 5 4 ground referenced signal sources PFIO TRIGI 5 4 description 3 4 lowpass filtering 5 7 to 5 16 differential
65. le measurements keep the SCB 68 away from drafts or other temperature gradients such as those caused by heaters radiators fans and very warm equipment To minimize temperature gradients keep the cover of the SCB 68 closed and add custom insulation such as foam tape to the SCB 68 Switch Settings and Temperature Sensor Configuration To accommodate thermocouples with DAQ devices the SCB 68 has a temperature sensor for CJC To power the temperature sensor set switches S1 S2 and S3 as shown in Figures 4 1 and 4 2 Notice that this configuration also powers on the signal conditioning accessory power Signal conditioning accessories include temperature sensors and signal conditioning circuitry For single ended operation connect referenced single ended analog channel 0 to the temperature sensor by switching S5 to the up position The signal is referenced to AIGND Set the switches as shown in Figure 4 1 SCB 68 Shielded Connector Block User Manual 4 2 ni com Chapter 4 Using Thermocouples Temperature Sensor S5 84 S3 Signal Conditioning Circuitry Power On Figure 4 1 Single Ended Switch Configuration For differential operation connect differential analog channel 0 to the temperature sensor by switching S5 and S4 to the up position as shown in Figure 4 2 Temperature Sensor S5 84 S3 Signal Conditioning Circuitry Power On S1 S2 OJO Figure 4
66. m transfer rate of 132 MB s Programmable Function Input PFIO trigger 1 PFIl trigger 2 PFI2 convert PFI3 general purpose counter 1 source PFI4 general purpose counter 1 gate PFI5 update PFI6 waveform trigger PFI7 start of scan PFI8 general purpose counter 0 source PFI9 general purpose counter 0 gate Programmable Gain Instrumentation Amplifier 1 acommunications connection on a computer or a remote controller 2 a digital port consisting of four or eight lines of digital input and or output ni com PXI R range RC filter resolution RH rms RSE S SCANCLK SCSI SE settling time signal conditioning SOURCE STARTSCAN National Instruments Corporation G 7 Glossary PCI eXtensions for Instrumentation an open specification that builds off the CompactPCI specification by adding instrumentation specific features the maximum and minimum parameters between which a device operates with a specified set of characteristics resistor capacitor filter the smallest signal increment that can be detected by a measurement system is expressed in bits proportions or percent of full scale relative humidity root mean square referenced single ended mode all measurements are made with respect to a common reference measurement system or a ground also called a grounded measurement system seconds samples scan clock signal small computer system interface single ended a term used to desc
67. mentation amplifier on the DAQ device RSE input mode is not recommended for grounded signal sources To leave the SCB 68 inputs in the factory configuration with jumpers in the series position F or G depending on the channel do not use the open positions that connect the input to AIGND A and C refer to Figure 5 1 SCB 68 Shielded Connector Block User Manual 3 4 ni com Chapter 3 Connecting Signals Analog Input Channel Configuration Diagram for ACH lt i gt and ACH lt i 8 amp gt Any signal conditioning circuitry requiring a ground reference should be built in the custom breadboard area using AISENSE as the ground reference instead of building the circuitry in the open component positions Referencing the signal to AIGND can cause inaccurate measurements resulting from an incorrect ground reference iyi Note Some versions of the SCB 68 use hardwired 0 Q resistors as the factory default jumpers In such cases to move these jumpers to and from the factory default positions you must solder and desolder on the SCB 68 circuit card assembly When soldering refer to Appendix E Soldering and Desoldering on the SCB 68 Differential Connection Considerations DIFF Input Mode A differential connection is one in which the DAQ device AI signal has its own reference signal or signal return path These connections are available when the selected channel is configured in DIFF input mode The input signal is tied to the positive input of the
68. ned to do so If signal wires are connected to the SCB 68 dangerous voltages may exist even when the equipment is powered off To avoid dangerous electrical shock do not perform procedures involving cover or shield removal unless you are qualified to do so Before you remove the cover disconnect the AC power or any live circuits from the SCB 68 The chassis GND terminals are for grounding high impedance sources such as floating sources 1 mA maximum Do nof use these terminals as safety earth grounds Do not connect high voltages to the SCB 68 even with an attenuator circuit Vever connect voltages 242 Vms NI is not liable for any damage or injuries resulting from improper use or connection National Instruments Corporation 2 1 SCB 68 Shielded Connector Block User Manual Chapter 2 Parts Locator and Wiring Guide g 000000000000 1 Q8 oR20a8 Co oo 0 000 000000000 O omR21n 00000000000000000 i o olc4 jo fooo00000 000000000 n wu JL OH En faz WEL
69. nts reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s
70. onditioning 5 3 to 5 4 component locations table 5 3 configuration diagram figure 5 3 SCB 68 Shielded Connector Block User Manual Index DACOOUT configuration diagram figure 5 4 input attenuators 5 22 5 23 lowpass filter considerations 5 12 5 14 to 5 15 analog output signal connections description 3 10 to 3 11 switch settings table 4 4 antialiasing filtering 5 13 to 5 14 attenuating voltage 5 18 to 5 24 adding components analog output and digital input attenuators 5 22 differential input attenuators 5 21 single ended input attenuators 5 20 to 5 21 selecting components 5 20 accuracy considerations 5 20 special considerations analog input 5 22 to 5 23 analog output 5 23 digital inputs 5 24 theory of operation 5 19 bias resistors for DIFF connection 3 7 C cable installation 1 5 to 1 10 68 pin cables 1 5 to 1 6 connecting to SCB 68 figure 1 6 quick reference label table 1 2 100 pin cables 1 6 to 1 10 connecting to SCB 68 figure 1 7 pin assignments SCB 68 E Series I O Connector pinout extended AT figure 1 9 SCB 68 Shielded Connector Block User Manual SCB 68 E Series I O Connector pinout extended digital figure 1 10 SCB 68 E Series I O Connector pinout full figure 1 8 quick reference labels table 1 2 calibration certificate F 2 CE compliance specifications A 3 channel pad configurations 5 2 to 5 4 analog input channels 5 2 to 5 3 component locations tab
71. ons to decrease the amplitude of a signal American wire gauge Celsius channel pin or wire lead to which you apply or from which you read the analog or digital signal Analog signals can be single ended or differential For digital signals you group channels to form ports Ports usually consist of either four or eight digital channels SCB 68 Shielded Connector Block User Manual G 2 ni com cm cold junction compensation CompactPCI CONVERT counter timer CTR D DAC DACOOUT DACIOUT DAQ dB DC DGND DIFF DIO DMA DoC National Instruments Corporation G 3 Glossary centimeter CJC an artificial reference level that compensates for ambient temperature variations in thermocouple measurement circuits refers to the core specification defined by the PCI Industrial Computer Manufacturer s Group PICMG convert signal a circuit that counts external pulses or clock pulses timing counter digital to analog converter an electronic device often an integrated circuit that converts a digital number into a corresponding analog voltage or current analog channel 0 output signal analog channel output signal data acquisition a system that uses the computer to collect receive and generate electrical signals decibel the unit for expressing a logarithmic measure of the ratio of two signal levels dB 20log10 V1 V2 for signals in volts direct current digital ground signal differenti
72. ouples into the signal connections than in differential modes The coupling is the result of differences in the signal path Magnetic coupling is proportional to the area between the two signal conductors Electrical coupling is a function of how much the electric field differs between the two conductors SCB 68 Shielded Connector Block User Manual 3 8 ni com Chapter 3 Connecting Signals Single Ended Connections for Floating Signal Sources RSE Input Mode Figure 3 4 shows how to connect a floating signal source to a channel on the DAQ device configured for RSE input mode Floating Signal Source Instrumentation O I O Connector ACH Amplifier PGIA 2 Measured AISENSE Voltage AIGND T 2 V Measurement Device Configured in RSE Input Mode Not all devices support RSE input mode Figure 3 4 Single Ended Input Connections for Nonreferenced or Floating Signals Single Ended Connections for Grounded Signal Sources NRSE Input Mode To measure a grounded signal source with a single ended configuration configure the DAQ device in NRSE input mode The signal is then connected to the positive input of the DAQ device instrumentation amplifier and the signal local ground reference is connected to the negative input of the instrumentation amplifier The ground point of the signal should therefore be connected to AISENSE Any potential difference between the DAQ device groun
73. pen component pads allow signal conditioning to be easily added to the analog input AI signals and to the DACOOUT DACIOUT and PFIO TRIGI signals of a 68 pin or 100 pin DAQ device What You Need to Get Started To set up and use the SCB 68 you need the following items Q D D D Oovovovo oO National Instruments Corporation SCB 68 68 pin shielded connector block One of the devices listed in Table 1 1 One of the device compatible cables listed in Table 1 1 The device user manual or user guide which you can access at ni com manuals Phillips number 1 and number 2 screwdrivers 0 125 in flathead screwdriver Long nose pliers Wire cutters Wire insulation strippers Quick reference label for the DAQ device you are using 1 1 SCB 68 Shielded Connector Block User Manual Chapter 1 Introduction Q The following items if you are adding components optional Soldering iron and solder Resistors Capacitors Quick Reference Label A quick reference label for E Series devices is included in this kit Quick reference labels for some other devices ship with the DAQ device itself These labels show the switch configurations and define the screw terminal pinouts for compatible DAQ devices You can put the label on the inside of the SCB 68 cover for easy reference if you are using one of these devices Refer to Appendix B Quick Reference Labels for the switch configurations and screw terminal pinout
74. position RC1 and the capacitor to position R1 SCB 68 Shielded Connector Block User Manual 5 12 ni com Chapter 5 Adding Components for Special Functions Lowpass Filtering Applications Noise filtering and antialiasing are two applications that use lowpass filters Noise Filtering You can use a lowpass filter to highly attenuate the noise frequency on a measured signal For example power lines commonly add a noise frequency of 60 Hz Adding a filter with f 60 Hz at the input of the measurement system causes the noise frequency to fall into the stopband Referring to Equation 5 4 fix the resistor value at 10 kQ to calculate the capacitor value and choose a commercial capacitor value that satisfies the following relationship 1 C 5540 000 60 ee Antialiasing Filtering Aliasing causes high frequency signal components to appear as a low frequency signal as Figure 5 14 shows Input Signal Sampled Points Reconstructed Signal Figure 5 14 Aliasing of a High Frequency Signal The solid line depicts a high frequency signal being sampled at the indicated points When these points are connected to reconstruct the waveform as shown by the dotted line the signal appears to have a lower frequency Any signal with a frequency greater than one half of its sample rate is aliased and incorrectly analyzed as having a frequency below one half the sample rate This limiting frequency of one half the
75. ql BIE ILO S O 24000000000055 Ford oo So o R18 F O000000000 Sem ra Fol 579099900900 22 o4 Pool ILL RT du aegre lol PL tO 23 6000000000 56 0 45 Em oe 8000000000 n SCB 68 0000000000 Pa COPYRIGHT 1993 9999909999 z 8 e O NOOR WD Pads R20 and R21 Switches S3 S4 and S5 68 Pin I O Connector Fuse 0 8 A Switches S1 and S2 Assembly Number and Revision Letter Screw Terminals 8 Serial Number 9 RC Filters and Attenuators for DACO DAC1 and TRIG1 10 Breadboard Area 11 Temperature Sensor 12 Product Name 13 Pads for Al Conditioning SCB 68 Shielded Connector Block User Manual Figure 2 1 SCB 68 Printed Circuit Diagram 2 2 ni com Chapter 2 Parts Locator and Wiring Guide To connect signals to the SCB 68 complete the following steps while referring to Figure 1 1 SCB 68 Parts Locator Diagram and to Figure 2 1 1 2 7 8 Disconnect the 68 pin cable from the SCB 68 if it is connected Remove the shielding screws on either side of the top cover with a Phillips head number 1 screwdriver You can now open the box Configure the switches and other options relative to the types of signals you are using Loosen the strain relief screws with a Phillips head number 2 screwdriver Slide the signal wires through the front panel strain relief opening You can also remove the top strain relief bar if you are connecting many signals Add insulation or padding if ne
76. r the maximum 5 V current draw which is limited by the fuse is 800 mA Fuse Manufacturer eeeeeeeee Littelfuse Part n mb r iet pae 235 800 Ampere rating seeeeeeeee 0 800 A National Instruments Corporation A 1 SCB 68 Shielded Connector Block User Manual Chapter A Specifications Physical Voltage rating oe eee eee eeeeereeeeee 250 V Nominal resistance sseeeeeene 0 195 Q Box dimensions including box feet 19 5 by 15 2 by 4 5 cm 7 7 by 6 0 by 1 8 in VO connectors One 68 pin male SCSI connector Screw terminals esses 68 Wire ga Be esce neioii lt 26 AWG Resistor sockets esssssssssss 0 032 to 0 038 in in diameter Maximum Working Voltage Environmental Maximum working voltage refers to the signal voltage plus the common mode voltage Channel to earth esses 42 Vims Installation Category II Channel to channel 42 Vims Installation Category II Operating temperature sesse 0 to 70 C Storage temperature ee eee 20 to 70 C Humidity 53e 5 to 90 RH noncondensing Maximum altitude sse 2000 meters Pollution Degree indoor use only II SCB 68 Shielded Connector Block User Manual A 2 ni com Chapter A Specifications Safety The SCB 68 meets the requirements of the following standards for safety and electrica
77. r the maximum voltage for which the SCB 68 is rated Do not exceed the maximum ratings for the SCB 68 Remove power from signal lines before connecting them to or disconnecting them from the SCB 68 Operate the SCB 68 only at or below the installation category stated in Appendix A Specifications The following is a description of installation categories Installation Category I is for measurements performed on circuits not directly connected to MAINS This category is a signal level such as voltages on a printed wire board PWB on the secondary of an isolation transformer Examples of Installation Category I are measurements on circuits not derived from MAINS and specially protected internal MAINS derived circuits Installation Category II is for measurements performed on circuits directly connected to the low voltage installation This category refers to local level distribution such as that provided by a standard wall outlet Examples of Installation Category II are measurements on household appliances portable tools and similar equipment Installation Category III is for measurements performed in the building installation This category is a distribution level referring to hardwired equipment that does not rely on standard building insulation Examples of Installation Category III include measurements on distribution circuits and circuit breakers Other examples of Installation Category III are wiring including cables bus ba
78. r will be required to correct the interference at his own expense Canadian Department of Communications This Class A digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe A respecte toutes les exigences du R glement sur le mat riel brouilleur du Canada Class B Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna Increase the separation between the equipment and receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help Canadian Dep
79. ranging between 4 and 20 mA Theory of Operation The conversion from current to voltage is based on Ohm s Law which is summarized by Equation 5 7 where V is voltage I is current and R is resistance V 2IxR 5 7 Thus you must multiply current by a constant to convert the current to a voltage In an electrical circuit current must flow through a resistor to produce a voltage drop This voltage drop then becomes the input for a DAQ device as Figure 5 18 shows SCB 68 Shielded Connector Block User Manual 5 16 ni com Chapter 5 Adding Components for Special Functions l gt e e Transducer E R Vm Input e e Figure 5 18 Current to Voltage Electrical Circuit The application software must linearly convert voltage back to current Equation 5 8 demonstrates this conversion where the resistor is the denominator and V is the input voltage into the DAQ device pec 5 8 Selecting a Resistor For best results when measuring current you should choose a resistor that has the following characteristics e Low wattage of approximately 1 8 W e Precision of at least 5 e Temperature stability e Tolerance of 596 e 232 Q suggested e AXL package suggested e Carbon or metal film suggested If you use the resistor described above you can convert a 20 mA current to 4 64 V by setting the device range to either 5 to 5 V or 0 to 5 V National Instruments Corporation 5 17 SCB 68 Shi
80. ribe an analog input that is measured with respect to a common ground the amount of time required for a voltage to reach its final value within specified limits the manipulation of signals to prepare them for digitizing source signal start scan signal SCB 68 Shielded Connector Block User Manual Glossary T thermocouple TRIG TTL U unipolar UPDATE waveform WFTRIG a temperature sensor created by joining two dissimilar metals the junction produces a small voltage as a function of the temperature trigger signal transistor transistor logic a signal range that is always positive for example 0 to 10 V update signal volts volts direct current volts in measured voltage volts out volts root mean square multiple voltage readings taken at a specific sampling rate waveform generation trigger signal SCB 68 Shielded Connector Block User Manual G 8 ni com Index Numbers 5 V signal fuse and power considerations C 1 power supply figure D 1 68 pin cables connecting to SCB 68 figure 1 6 installing 1 5 to 1 6 quick reference label table 1 2 100 pin cables connecting to SCB 68 figure 1 7 installing 1 6 to 1 10 pin assignments SCB 68 E Series I O Connector pinout extended AJ figure 1 9 SCB 68 E Series I O Connector pinout extended digital figure 1 10 SCB 68 E Series I O Connector pinout full figure 1 8 quick reference labels table 1 2 A accurac
81. ribution circuits are improperly connected If a grounded signal source is incorrectly measured this difference may appear as a measurement error The connection instructions for grounded signal sources are designed to eliminate this ground potential difference from the measured signal Differential Inputs If the DAQ device is configured for DIFF input mode where ACH lt i gt and ACH lt i 8 gt are used as a single differential channel pair ground referenced signal sources connected to the SCB 68 need no special components You can leave the inputs of the SCB 68 in the factory configuration with the jumpers in the two series positions F and G Refer to Figure 5 1 Analog Input Channel Configuration Diagram for ACH i and ACH lt i 8 gt fora diagram of this configuration rsions of the SCB 68 use hardwired 0 Q resistors as the factory default jumpers In such cases to move these jumpers to and from the factory default positions you must solder and desolder on the SCB 68 circuit card assembly When soldering refer to Appendix E Soldering and Desoldering on the SCB 68 Single Ended Inputs When you measure ground referenced single ended signals the external signal supplies its own reference ground point and the DAQ device should not supply one Therefore you should configure the DAQ device for NRSE input mode In this input mode connect all the signal grounds to AISENSE pin which connects to the negative input of the instru
82. ring on the SCB 68 for more information about adding components and for soldering and desoldering instructions After building one of the applications described in this chapter or your own custom circuitry refer to the Configuring the SCB 68 section of Chapter 1 Introduction for instructions about how to configure the SCB 68 in MAX National Instruments Corporation 5 1 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions You can create virtual channels in MAX to map your voltage ranges to the type of transducer that you are using or to create a custom scale Channel Pad Configurations When you use the SCB 68 with a 68 pin or 100 pin DAQ device you can use the component pads on the SCB 68 to condition 16 AI channels two AO channels and PFIO TRIGI Conditioning Analog Input Channels Figure 5 1 illustrates the AI channel configuration ACH lt i gt and ACH lt i 8 gt can be used as either a differential channel pair or as two single ended channels Table 5 1 correlates the component labels of the SCB 68 to component locations A G for differential channels 0 7 In the component names in Table 5 1 R denotes a resistor and C denotes a capacitor Component locations labeled RCX provide sockets for two components a resistor and a capacitor to be connected in parallel 45V ACH i p pn EL m O
83. round system but has an isolated ground reference point Instruments or devices with isolated outputs are considered floating signal sources and they have high impedance paths to ground Some examples of floating signal sources are outputs for thermocouples transformers battery powered devices optical isolators and isolation amplifiers The ground reference of a floating source must be tied to the ground of the DAQ device to establish a local or onboard reference for the signal Otherwise the measured input signal varies as the source floats outside the common mode input range Differential Inputs When measuring differential floating sources you must configure the device for DIFF input mode To provide a return path for the instrumentation amplifier bias currents differential floating sources must have a 10 to 100 KQ resistor connected to AIGND on one input if they are DC coupled or on both inputs if sources are AC coupled You can install bias resistors in positions B and D of the SCB 68 as shown in Figure 5 1 Analog Input Channel Configuration Diagram for ACH lt i gt and ACH lt i 8 gt Single Ended Inputs When measuring single ended floating signal sources you must configure the DAQ device to supply a ground reference by configuring the DAQ device for RSE input mode In this mode the negative input of the instrumentation amplifier on the DAQ device is tied to the analog ground To use the SCB 68 with single ended inputs where
84. rs junction boxes switches socket outlets in the building fixed MAINS is defined as the electricity supply system to which the equipment concerned is designed to be connected either for powering the equipment or for measurement purposes SCB 68 Shielded Connector Block User Manual 1 12 ni com Chapter 1 Introduction installation and equipment for industrial use such as stationary motors with a permanent connection to the building fixed installation Installation Category IV is for measurements performed at the source of the low voltage lt 1 000 V installation Examples of Installation Category IV are electric meters and measurements on primary overcurrent protection devices and ripple control units Below is a diagram of a sample installation Category IV Circuit Breaker Plug in Equipment Electric Meter Source of Building Fixed Local Level Secondary Low Voltage Installation Distribution Such Windings of 1000 V Distribution as Wall Sockets Isolation Installation Panel Transformers National Instruments Corporation 1 13 SCB 68 Shielded Connector Block User Manual Parts Locator and Wiring Guide This chapter explains how to connect signals to the SCB 68 The following cautions contain important safety information concerning hazardous voltages and terminal blocks N Cautions Keep away from live circuits Do not remove equipment covers or shields unless you are trai
85. s that are included on each quick reference label Table 1 1 shows cabling options and features for DAQ devices that are compatible with the SCB 68 Figure 1 1 shows where to apply the quick reference label to the inside cover of the SCB 68 Table 1 1 Device Specific Hardware Configuration Device Cable Assembly Features E Series Devices 68 Pin Devices except DAQCards SH68 68 EP SH68 68 R1 EP R6868 Direct feedthrough only Thermocouple measurements Open thermocouple detection Current input Filtering Voltage dividers AC coupling 100 Pin Devices SH1006868 Direct feedthrough only Thermocouple measurements Open thermocouple detection Current input Filtering Voltage dividers AC coupling SCB 68 Shielded Connector Block User Manual 1 2 ni com Chapter 1 Table 1 1 Device Specific Hardware Configuration Continued DAQCard AI 16E 4 Device Cable Assembly Features NI 6024E for PCMCIA SCH68 68 EP Direct feedthrough only DAQCard 6024E RC68 68 Thermocouple measurements NI 6036E for PCMCIA Open thermocouple detection DAQCard 6036E Current input NI 6062E for PCMCIA Filtering DAQCard 6062E Voltage dividers AC coupling NI 6012E for PCMCIA PSHR68 68 Direct feedthrough only DAQCard AI 16XE 50 PR68 68F Thermocouple measurements NI 6041E for PCMCIA Open thermocouple detection Current input Filtering Voltage dividers AC coupling Analog O
86. sample rate is known as the Nyquist frequency National Instruments Corporation 5 13 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions To prevent aliasing remove all signal components with frequencies greater than the Nyquist frequency from input signals before those signals are sampled Once a data sample is aliased it is impossible to accurately reconstruct the original signal To design a lowpass filter that attenuates signal components with a frequency higher than half of the Nyquist frequency substitute the half Nyquist value for the f value in Equation 5 6 The following devices provide antialiasing filters and do not need to have the filters implemented at the SCB 68 terminal block e NIPCI PXI 61XX not including the NI PCI 6110 6111 e NIPCI 445X e NIPCI 455X Special Consideration for Analog Input Channels Filtering increases the settling time of the instrumentation amplifier to the time constant of the filter used Adding RC filters to scanning channels greatly reduces the practical scanning rate since the instrumentation amplifier settling time can be increased to 10T or longer where T R C You can use RC filters with single ended or differential inputs Special Consideration for Analog Output Signals Lowpass filters can smooth stairstep like curves on AO signals If the curves are not smoothed the AO signals can be a hazard for some external circuitry connect
87. scription figure 3 2 differential connections 3 3 3 7 to 3 8 recommended configuration figure 3 2 single ended connections RSE input mode 3 3 3 9 NRSE nonreferenced single ended input See single ended connections 0 one pole lowpass RC filter 5 10 to 5 11 open thermocouple detection 5 5 to 5 7 differential 5 6 single ended 5 6 sources of error 5 6 to 5 7 P parts locator diagram figure 1 5 2 2 PFIO TRIGI signal conditioning figure 5 4 physical specifications A 2 pin assignments SCB 68 E Series I O Connector pinout extended AI figure 1 9 SCB 68 E Series I O Connector pinout extended digital figure 1 10 SCB 68 E Series I O Connector pinout full figure 1 8 power fuse and power C 1 power requirement specifications A 1 Q quick reference label 1 2 to 1 4 B 1 to B 8 analog output AO devices table 1 3 digital I O DIO devices table 1 3 E series devices table 1 2 to 1 3 B 2 SCB 68 Shielded Connector Block User Manual l 6 NI 653X devices table B 7 NI 660X devices table B 6 NI 670X devices table B 3 NI 671X 673X devices table B 4 NI 7811R 7831R devices table B 8 other devices table 1 4 real time RT devices table 1 3 S series devices table 1 4 B 5 timing I O TIO devices table 1 4 R real time RT devices quick reference label table 1 3 referenced single ended input RSE See single ended connections requirements for gett
88. starting with the letters EXN Trade Name Model Number or the FCC Class B compliance mark that appears as shown here on the right FE Tested to Comply with FCC Standards Consult the FCC Web site at http www fcc gov for more information FCC DOC Warnings This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the instructions in this manual and the CE Marking Declaration of Conformity may cause interference to radio and television reception Classification requirements are the same for the Federal Communications Commission FCC and the Canadian Department of Communications DOC FOR HOME OR OFFICE USE Changes or modifications not expressly approved by National Instruments could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the use
89. switches as shown below P N 185974A 01 SET SWITCHES AS FOLLOWS FOR NI 660X DEVICES MON MON Application Contexts Counter As shown on label DIO nz 0 31 DIO 0 maps to PFI 0 DIO n maps to PFI n Motion Encoder n 0 7 SOURCE_n maps to CH_A_n UP DOWN n maps to CH B n GATE n maps to CH Z n For details refer to ni com manuals for the user manual for NI 660X devices PIN SIGNAL GND PFI_31 SOURCE_2 PFI 30 GATE 2 SIGNAL PFI 3 SIGNAL GND GND RG PFI_29 UP DOWN 2 PFI_4 PFI_39 SOURCE 0 PFI 28 OUT 2 PFI 5 GND GND GND PFI 38 GATE 0 PFI 27 SOURCE 3 PFI 6 RESERVED PFI 26 GATE 3 PFI 7 RESERVED GND GND RESERVED PFI 25 UP DOWN 3 PFI 8 OUT 7 PFI 36 OUT 0 PFI 24 OUT 3 GND GND GND PFI_9 UP DOWN 7 PFI 33 UP DOWN 1 PFI 23 SOURCE 4 PFI 10 GATE 7 PFI 37 UP DOWN 0 PFI_22 GATE 4 GND PFI 35 SOURCE 1 GND PFI 11 SOURCE 7 GND PFI 21 UP DOWN 4 RG PFI_34 GATE 1 PFI 20 OUT 4 PFI 12 OUT 6 GND GND GND PFI 32 OUT 1 PFI 19 SOURCE 5 PFI 13 UP DOWN 6 RG PFI 18 GATE_5 PFI 14 GATE 6 PFI 0 GND GND PFI 1 PFI 17 UP DOWN 5 PFI_15 SOURCE 6 GND PFI 16 OUT 5 Figure B 5 NI 660X Devices SCB 68 Shielded Connector Block
90. t Attenuators To build a three resistor circuit for attenuating voltages at the differential inputs of the SCB 68 refer to Figure 5 21 6 AAA ec Vin Re RE Vm e AAA ACH lt i 8 gt Figure 5 21 SCB 68 Circuit Diagram for DIFF Input Attenuation Install resistors in positions E F and G of the chosen differential channel pair Use Equation 5 16 to determine the gain of the circuit Rg G 5 16 Rg Rp Ro National Instruments Corporation 5 21 SCB 68 Shielded Connector Block User Manual Chapter 5 Adding Components for Special Functions Analog Output and Digital Input Attenuators To build a two resistor circuit for attenuating voltages at the DACOOUT DACIOUT and TRIGI pins on the SCB 68 refer to the pad positions in Figure 5 22 ACH lt i gt ri 6 e Vin Rg E Vm e ACH i8 Figure 5 22 SCB 68 Circuit Diagram for Digital Input Attenuation Use positions R1 and RC1 for TRIGI and determine the gain according to Equation 5 17 RCO _ 5 17 RC1 R1 Use positions R2 and RC2 for DAC1OUT and determine the gain according to Equation 5 18 RC2 G 5 18 RC2 R2 Use positions R3 and RC3 for DACOOUT and determine the gain according to Equation 5 19 RC3 5 19 G _ RC3 R3 Special Considerations for Analog Input When calculating the values for R and R gt consider the input impedance value from the point of view of
91. the value for R Base the R calculation on the following values e Maximum V you expect from the transducer e Maximum voltage 10 Vpc that you want to input to the DAQ device Accuracy Considerations For best results when attenuating voltage you should choose a resistor that has the following characteristics e Low wattage of approximately 1 8 W e Precision of at least 5 Temperature stable e Tolerance of 5 e AXL package suggested e Carbon or metal film suggested Verify that R and R drift together with respect to temperature otherwise the system may consistently read incorrect values Adding Components You an build a two or three resistor circuit for attenuating voltages at the single ended inputs differential inputs analog outputs and digital inputs of the SCB 68 Single Ended Input Attenuators To build a two resistor circuit for attenuating voltages at the single ended inputs of the SCB 68 refer to Figure 5 20 SCB 68 Shielded Connector Block User Manual 5 20 ni com Chapter 5 Adding Components for Special Functions Vin RB D Vm e AIGND V Figure 5 20 SCB 68 Circuit Diagram for SE Input Attenuation Install resistors in positions B and F or positions D and G depending on the channel you are using on the SCB 68 Use Equations 5 14 or 5 15 to calculate the gain of the circuit Rg 5 14 Rpt Ry G fp _ 5 15 Rp Rg Differential Inpu
92. tial inputs 5 18 single ended inputs 5 18 National Instruments Corporation F3 SCB 68 Shielded Connector Block User Manual Index selecting resistor 5 17 theory of operation 5 16 to 5 17 D DACOOUT signal component location in DIFF input mode table 5 3 configuration diagram figure 5 4 DACIOUT signal component location table 5 3 Declaration of Conformity DoC F 1 desoldering and soldering E 1 to E 2 differential connections DIFF input mode component locations for analog input channels table 5 2 to 5 3 DACOOUT and DACIOUT signal component locations table 5 3 definition table 3 2 description 3 5 ground referenced signal sources 3 4 3 6 input attenuators 5 21 lowpass filter 5 12 measuring 4 20 mA current 5 18 nonreferenced or floating signal sources 3 3 3 7 to 3 8 open thermocouple detection 5 6 recommended configuration figure 3 2 temperature sensor switch configuration figure 4 3 when to use 3 5 digital input channels input attenuators 5 22 5 24 lowpass filter considerations 5 12 PFIO TRIGI configuration figure 5 4 digital I O DIO devices quick reference label table 1 3 digital signal connections description 3 11 to 3 12 switch settings table 4 4 SCB 68 Shielded Connector Block User Manual l 4 digital trigger circuitry diagram figure D 2 input signals lowpass filtering 5 15 to 5 16 documentation conventions used in manual xi NI documentation xii E
93. u must select or click on in the software such as menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts National Instruments Corporation Xi SCB 68 Shielded Connector Block User Manual About This Manual NI Documentation For more information about using the SCB 68 with DAQ devices refer to the following resources e DAQ device user manuals at ni com manuals e NI Developer Zone at ni com zone SCB 68 Shielded Connector Block User Manual Xii ni com Introduction The SCB 68 is a shielded I O connector block with 68 screw terminals for easy signal connection to a National Instruments 68 or 100 pin DAQ device The SCB 68 features a general breadboard area for custom circuitry and sockets for interchanging electrical components These sockets or component pads allow RC filtering 4 to 20 mA current sensing open thermocouple detection and voltage attenuation The o
94. utput AO Devices NI 670X SH68 68 D1 Direct feedthrough only for PCIPXI CompactPCI R6868 RC filtering NI 671X 673X SH68 68 EP Direct feedthrough only for PCI PXI CompactPCI SH68 68 R1 EP RC filtering R6868 NI 6715 for PCMCIA SHC68 68 EP Direct feedthrough only DAQCard 6715 RC6868 RC filtering Digital I O DIO Devices NI 6533 for ISA PCI JPXI CompactPCI SH68 68 D1 R6868 Direct feedthrough only NI 6533 for PCMCIA PSHR68 68 D1 Direct feedthrough only DAQCard 6533 PR6868F NI 6534 SH68 68 D1 Direct feedthrough only for PCIPXI CompactPCI R6868 Real Time RT Devices NI 7030 6030E SH68 68 EP Direct feedthrough only for PCIPXI CompactPCI SH68 68R1 EP Thermocouple measurements NI 7030 6040E R6868 Open thermocouple detection for PCIPXI CompactPCI Current input Filtering Voltage dividers AC coupling NI 7030 6533 SH68 68 D1 Direct feedthrough only for PCIPXI CompactPCI R6868 National Instruments Corporation 1 3 SCB 68 Shielded Connector Block User Manual Introduction Chapter 1 Introduction Table 1 1 Device Specific Hardware Configuration Continued Device Cable Assembly Features S Series Devices NI 6110 6111 for PCI SH68 68 EP Direct feedthrough only SH68 68R1 EP R6868 NI 6115 6120 SH68 68 EP Direct feedthrough only for PCIPXI CompactPCI SH68 68R1 EP R6868 Timing I O TIO Devices NI 6601 6602 SH68 68 D1 Direct f
95. wires between signal sources and the device The following recommendations apply mainly to AI signal routing to the device although they also apply to signal routing in general Minimize noise pickup and maximize measurement accuracy by taking the following precautions Use differential AI connections to reject common mode noise if the DAQ device that you are using supports DIFF input mode e Use individually shielded twisted pair wires to connect AI signals to the device With this type of wire the signals attached to the National Instruments Corporation 3 13 SCB 68 Shielded Connector Block User Manual Chapter 3 Connecting Signals ACH and ACH inputs are twisted together and then covered with a shield You then connect this shield at only one point to the signal source ground This kind of connection is required for signals traveling through areas with large magnetic fields or high electromagnetic interference Route signals to the device carefully Keep cabling away from noise sources A common noise source in DAQ applications is the computer monitor Separate the monitor from the analog signals as far as possible The following recommendations apply for all signal connections to the DAQ device Separate DAQ device signal lines from high current or high voltage lines These lines can induce currents in or voltages on the DAQ device signal lines if they run in parallel paths at a close distance To reduce the magnetic
96. y and resolution of voltage measurement 5 5 ACH lt i gt and ACH lt i 8 gt analog input channel configuration figure 5 2 adding components 5 1 to 5 24 accuracy and resolution considerations 5 5 attenuating voltage 5 18 to 5 24 channel pad configurations 5 2 to 5 4 lowpass filtering 5 7 to 5 16 measuring current 5 16 to 5 18 open thermocouple detection 5 5 to 5 7 analog input channels conditioning 5 2 to 5 3 National Instruments Corporation component locations table 5 2 to 5 3 configuration diagram figure 5 2 input attenuators 5 22 to 5 23 lowpass filter considerations 5 14 specifications A 1 analog input signal connections 3 1 to 3 10 differential connections DIFF input mode description 3 5 ground referenced signal sources 3 4 3 6 nonreferenced or floating signal sources 3 3 3 7 to 3 8 ground referenced signal sources description 3 4 differential inputs 3 4 3 6 single ended inputs 3 4 to 3 5 3 9 to 3 10 input modes recommended input modes figure 3 2 types of 3 1 nonreferenced or floating signal sources description 3 3 differential inputs 3 3 3 7 to 3 8 single ended inputs 3 3 3 9 single ended connections description 3 8 ground referenced signal sources 3 4 to 3 5 3 9 to 3 10 nonreferenced or floating signal sources 3 3 3 9 switch configuration table 4 4 analog output AO devices quick reference label table 1 3 analog output channels circuitry diagram figure D 3 c

National Instruments SCB-68 User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents