National Instruments SCB-68 - Manuals

© National Instruments Corporation vii SCB-68 Shielded Connector Block User Manual Contents About This Manual Conventions ................................................................................................................... xiNI Documentation...............................................

Contents © National Instruments Corporation ix SCB-68 Shielded Connector Block User Manual Selecting a Resistor ......................................................................................... 5-17Adding Components ...............................................................................

© National Instruments Corporation xi SCB-68 Shielded Connector Block User Manual About This Manual This manual describes the SCB-68 and explains how to use the connector block with National Instruments data acquisition (DAQ) devices. Conventions The following conventions appear in this manual: <...

About This Manual SCB-68 Shielded Connector Block User Manual xii ni.com NI Documentation For more information about using the SCB-68 with DAQ devices, refer to the following resources: • DAQ device user manuals, at ni.com/manuals • NI Developer Zone, at ni.com/zone

© National Instruments Corporation 1-1 SCB-68 Shielded Connector Block User Manual 1 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 cus...

Chapter 1 Introduction SCB-68 Shielded Connector Block User Manual 1-2 ni.com ❑ 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 referen...

Chapter 1 Introduction © National Instruments Corporation 1-5 SCB-68 Shielded Connector Block User Manual 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. Note F...

Chapter 1 Introduction © National Instruments Corporation 1-11 SCB-68 Shielded Connector Block User Manual Configuring the SCB-68 For instructions about using Measurement & Automation Explorer (MAX) to configure the SCB-68 as an accessory for a DAQ device, complete the following steps: 1. Naviga...

© National Instruments Corporation 2-1 SCB-68 Shielded Connector Block User Manual 2 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. Cautions Keep...

Chapter 2 Parts Locator and Wiring Guide © National Instruments Corporation 2-3 SCB-68 Shielded Connector Block User Manual 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. Disconnect the 68-pin cable f...

Chapter 2 Parts Locator and Wiring Guide SCB-68 Shielded Connector Block User Manual 2-4 ni.com Table 2-1. Switch Configurations and Affected Signals Switch Setting Applicable Signals Direct feedthrough, with temperature sensor disabled and accessory power disabled Analog input, analog output, digit...

© National Instruments Corporation 3-1 SCB-68 Shielded Connector Block User Manual 3 Connecting Signals This chapter describes the types of signal sources that you use when configuring the channels and making signal connections to the SCB-68, describes input modes, and discusses noise considerations...

Chapter 3 Connecting Signals © National Instruments Corporation 3-3 SCB-68 Shielded Connector Block User Manual Nonreferenced or Floating Signal Sources A floating signal source is a signal source that is not connected in any way to the building ground system, but has an isolated ground-reference po...

Chapter 3 Connecting Signals SCB-68 Shielded Connector Block User Manual 3-4 ni.com Ground-Referenced Signal Sources 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 dev...

Chapter 3 Connecting Signals © National Instruments Corporation 3-5 SCB-68 Shielded Connector Block User Manual Analog Input Channel Configuration Diagram for ACH<i> and ACH<i+8> ). Any signal conditioning circuitry requiring a ground reference should be built in the custom breadboard ar...

Chapter 3 Connecting Signals © National Instruments Corporation 3-7 SCB-68 Shielded Connector Block User Manual 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....

Chapter 3 Connecting Signals SCB-68 Shielded Connector Block User Manual 3-8 ni.com Common-mode rejection might be improved by using another bias resistor between ACH+ or ACH< i >, and AIGND. This connection creates a slight measurement error caused by the voltage divider formed with the outpu...

Chapter 3 Connecting Signals SCB-68 Shielded Connector Block User Manual 3-10 ni.com Figure 3-5 shows how to connect a grounded signal source to a channel on the DAQ device configured for NRSE input mode. Figure 3-5. Single-Ended Input Connections for Ground-Referenced Signals Connecting Analog Outp...

Chapter 3 Connecting Signals © National Instruments Corporation 3-11 SCB-68 Shielded Connector Block User Manual Figure 3-6 shows how to make AO connections and the external reference connection to the SCB-68 and the DAQ device. Figure 3-6. Connecting AO Signals Connecting Digital Signals When using...

Chapter 3 Connecting Signals SCB-68 Shielded Connector Block User Manual 3-12 ni.com 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 &l...

Chapter 3 Connecting Signals © National Instruments Corporation 3-13 SCB-68 Shielded Connector Block User Manual 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. Figure 3-8. Timing I/O Connectio...

© National Instruments Corporation 4-1 SCB-68 Shielded Connector Block User Manual 4 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...

Chapter 4 Using Thermocouples SCB-68 Shielded Connector Block User Manual 4-2 ni.com 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...

Chapter 4 Using Thermocouples © National Instruments Corporation 4-3 SCB-68 Shielded Connector Block User Manual 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 sho...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-2 ni.com 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...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-3 SCB-68 Shielded Connector Block User Manual 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. Fig...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-4 ni.com Figure 5-3. Analog Output Channel Configuration Diagram for DAC0OUT Conditioning PFI0/TRIG1 Figure 5-4 illustrates the digital input channel configuration, and Figure 5-5 shows the digital input ...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-5 SCB-68 Shielded Connector Block User Manual Accuracy and Resolution Considerations When you measure voltage to subsequently measure current, take the following steps to maximize measurement accuracy: 1. Refer to...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-6 ni.com 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. ...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-7 SCB-68 Shielded Connector Block User Manual Thermocouple wire error is the result of inconsistencies in the thermocouple manufacturing process. These inconsistencies, or nonhomogeneities, are the result of defec...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-10 ni.com 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 ) ...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-11 SCB-68 Shielded Connector Block User Manual 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 c . In this ...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-12 ni.com For any type of lowpass filter, use Equation 5-5 to determine the cut-off frequency ( f c ). (5-5) Single-Ended Lowpass Filter To build a single-ended lowpass filter, refer to Figure 5-12. Add t...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-13 SCB-68 Shielded Connector Block User Manual Lowpass Filtering Applications Noise filtering and antialiasing are two applications that use lowpass filters. Noise Filtering You can use a lowpass filter to highly ...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-14 ni.com 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 im...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-15 SCB-68 Shielded Connector Block User Manual Figure 5-15. Lowpass Filtering of AO Signals Special Consideration for Digital Trigger Input Signals Lowpass filters can function as debouncing filters to smooth nois...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-16 ni.com Apply a lowpass filter to the signal to remove the high-frequency component for a cleaner digital signal, as Figure 5-17 shows. Figure 5-17. Lowpass Filtering of Digital Trigger Input Signals No...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-17 SCB-68 Shielded Connector Block User Manual Figure 5-18. Current-to-Voltage Electrical Circuit The application software must linearly convert voltage back to current. Equation 5-8 demonstrates this conversion, ...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-18 ni.com Adding Components 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 ci...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-20 ni.com Selecting Components To set up the resistors, complete the following steps: 1. Select the value for R 2 (10 k Ω is recommended). 2. Use Equation 5-12 to calculate the value for R 1 . Base the R ...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-21 SCB-68 Shielded Connector Block User Manual 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 t...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-22 ni.com Analog Output and Digital Input Attenuators To build a two-resistor circuit for attenuating voltages at the DAC0OUT, DAC1OUT, and TRIG1 pins on the SCB-68, refer to the pad positions in Figure 5...

Chapter 5 Adding Components for Special Functions © National Instruments Corporation 5-23 SCB-68 Shielded Connector Block User Manual Figure 5-23. Input Impedance Electrical Circuit Z in is the new input impedance. Refer to Appendix A, Specifications , in the device user manuals at ni.com/manuals fo...

Chapter 5 Adding Components for Special Functions SCB-68 Shielded Connector Block User Manual 5-24 ni.com Special Considerations for Digital Inputs If you use the V in voltage of Figure 5-20 to feed TTL signals, you must calculate V in so that the voltage drop on R 2 does not exceed 5 V. Caution A v...

© National Instruments Corporation A-1 SCB-68 Shielded Connector Block User Manual A 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...

Chapter A Specifications SCB-68 Shielded Connector Block User Manual A-2 ni.com Voltage rating .........................................250 V Nominal resistance .................................0.195 Ω Physical Box dimensions (including box feet)......19.5 by 15.2 by 4.5 cm (7.7 by 6.0 by 1.8 in.) I...

Chapter A Specifications © National Instruments Corporation A-3 SCB-68 Shielded Connector Block User Manual Safety The SCB-68 meets the requirements of the following standards for safety and electrical equipment for measurement, control, and laboratory use: • IEC 61010-1, EN 61010-1 • UL 3111-1 • CA...

© National Instruments Corporation B-1 SCB-68 Shielded Connector Block User Manual B Quick Reference Labels This appendix shows the pinouts that appear on the quick reference labels for the DAQ devices that are compatible with the SCB-68.

Chapter B Quick Reference Labels SCB-68 Shielded Connector Block User Manual B-2 ni.com Figure B-1. E Series Devices DAC1 OUT DAC0 OUT SCANCLK EXTREF AOGND AOGND AIGND DIO5 51 ACH4 S4 * 68 GENERIC TERMINALS ACCESSORY POWER OFF) (TEMP. SENSOR AND S4 * ACCESSORY POWER ON ON DIFFERENTIAL CH. 0 * TEMP. ...

Chapter B Quick Reference Labels © National Instruments Corporation B-3 SCB-68 Shielded Connector Block User Manual Figure B-2. NI 670 X Devices S4 * 68 GENERIC TERMINALS ACCESSORY POWER OFF) (TEMP. SENSOR AND S5 23 57 S3 S2 S1 58 24 25 59 27 60 26 61 28 VCH1 66 ICH17* 62 29 30 63 64 31 32 65 AGND0/...

Chapter B Quick Reference Labels © National Instruments Corporation B-5 SCB-68 Shielded Connector Block User Manual Figure B-4. S Series Devices DAC1OUT DAC0OUT NC SCANCLK AOGND AOGND DIO5 51 S4 * 68 GENERIC TERMINALS ACCESSORY POWER OFF) (TEMP. SENSOR AND S4 * ACCESSORY POWER ON ON DIFFERENTIAL CH....

© National Instruments Corporation C-1 SCB-68 Shielded Connector Block User Manual C 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 us...

© National Instruments Corporation D-1 SCB-68 Shielded Connector Block User Manual D SCB-68 Circuit Diagrams This appendix contains illustrations of circuit diagrams for the SCB-68. Figure D-1. +5 V Power Supply +5V (I/O Pin 8) +5V Screw Terminal ACC Not Powered (NC) C2 (10 µ F) XF1 (Clip) 800 mA 5x...

© National Instruments Corporation E-1 SCB-68 Shielded Connector Block User Manual E 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 desolde...

Chapter F Technical Support and Professional Services SCB-68 Shielded Connector Block User Manual F-2 ni.com • 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 ...

© National Instruments Corporation G-1 SCB-68 Shielded Connector Block User Manual Glossary Prefix Meanings Value p- pico 10 – 12 n- nano- 10 – 9 µ - micro- 10 – 6 m- milli- 10 – 3 k- kilo- 10 3 M- mega- 10 6 G- giga- 10 9 Numbers/Symbols ° degrees > greater than ≤ less than or equal to ≥ greater...

© National Instruments Corporation I-1 SCB-68 Shielded Connector Block User Manual Index Numbers +5 V signal fuse and power considerations, C-1power supply (figure), D-1 68-pin cables connecting to SCB-68 (figure), 1-6installing, 1-5 to 1-6quick reference label (table), 1-2 100-pin cables connecting...