DAQ BNC-2090A User Manual Rack-Mount Connector Accessory for E/M Series DAQ Devices BNC-2090A User Manual January 2007 372101A-01
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Important Information Warranty The BNC-2090A 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.
Compliance Compliance with FCC/Canada Radio Frequency Interference Regulations 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). All National Instruments (NI) products are FCC Class A products.
Conventions The following conventions are used 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, AO <3..0>. » 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.
Contents Chapter 1 BNC-2090A Overview What You Need to Get Started ......................................................................................1-2 Installing the BNC-2090A .............................................................................................1-3 Setting the BNC-2090A Shield Ground Jumper............................................................1-7 Chapter 2 Connecting Signals Connecting Analog Input Signals .................................................................
Contents Appendix A Specifications Appendix B Frequently Asked Questions Appendix C Technical Support and Professional Services Index BNC-2090A User Manual viii ni.
1 BNC-2090A Overview This user manual contains in-depth information about using the National Instruments BNC-2090A. The BNC-2090A is a desktop or rack-mount analog breakout accessory you can connect to E/M Series multifunction DAQ devices1.
Chapter 1 BNC-2090A Overview 1 2 3 4 NATIONAL INSTRUMENTS SE SE SE SE SE SE SE SE RSE DIFF DIFF DIFF DIFF DIFF DIFF DIFF DIFF NRSE 5 BNC-2090A 6 2 1 2 3 BNC Connectors 68-Position Connectors Spring Terminal Block 4 5 6 +5V LED SE/DIFF Switches RSE/NRSE Switch Figure 1-1.
Chapter 1 BNC-2090A Overview ❑ Small flathead screwdriver ❑ Four adhesive rubber feet (supplied) You can find detailed specifications for the BNC-2090A in Appendix A, Specifications. Installing the BNC-2090A The BNC-2090A Quick Start Guide contains general installation information for the BNC-2090A. To connect the BNC-2090A to your DAQ device, refer to Figure 1-2 as you complete the following steps. Consult your computer user manual or technical reference manual for specific instructions and warnings.
Chapter 1 BNC-2090A Overview 2. (Optional) If you need to connect the BNC-2090A shield directly to digital ground (D GND), verify that the shield ground jumper is set correctly for your current application. Refer to the Setting the BNC-2090A Shield Ground Jumper section for more information. 3. (Optional) If you are performing signal conditioning, determine what signal conditioning you need for analog inputs and install the necessary components into the open component positions.
Chapter 1 BNC-2090A Overview Figure 1-3 shows the BNC-2090A connected directly to different M Series DAQ systems.
Chapter 1 BNC-2090A Overview Figure 1-4 shows the BNC-2090A connected directly to different E Series DAQ systems. 68-Position Connector 68-Pin E Series DAQ Device 68-Position Connector SH68-68-EP or R6868 Cable 68-Position VHDCI Connector 68-Pin E Series DAQCard Device 68-Position Connector SHC68-68-EPM or RC68-68 Cable BNC-2090A MIO-16 68-Position Connector 100-Position Connector 100-Pin E Series DAQ Device BNC-2090A SH1006868 Cable BNC-2090A Extended DIO 68-Position Connector Figure 1-4.
Chapter 1 BNC-2090A Overview all devices connected to it, and the host computer. Overvoltage can also cause an electric shock hazard for the operator. National Instruments is not liable for damage or injury resulting from such misuse. Setting the BNC-2090A Shield Ground Jumper The BNC-2090A shield ground jumper, labeled W1 on the PCB, is factory-configured to connect the shield of the 68-position connectors and BNC-2090A metal case through a 100 Ω resistor to D GND.
Chapter 1 BNC-2090A Overview 5 4 6 N T INA ST IONA RU L ME BN NT C-2 0 90 A S 2 1 1 2 3 Front Panel Screws Shield Ground Jumper (W1) 3 4 Side Panel Screw Rear Panel Screws 5 6 Top Screw Bottom Screw Figure 1-5. Accessing the Shield Ground Jumper BNC-2090A User Manual 1. Remove the two rear panel screws and one side panel screw. 2. Remove the top and bottom screws and two front panel screws. 3. Hold the front panel and slide the unit out of the metal case. 4.
2 Connecting Signals The BNC-2090A features 22 BNC connectors and a spring terminal block for analog and digital signal connection. Refer to the E Series User Manual or the M Series User Manual for information about the use of these signals. Figure 2-1 shows an overview of the BNC-2090A circuitry. Rear 68-Pin SCSI Connector AI/AO/APFI/PFI 0 DIO/PFI USER <1..2> BNC Connectors Front 68-Pin SCSI Connector Spring Terminals Figure 2-1.
Chapter 2 Connecting Signals Connecting Differential Analog Input Signals Complete the following steps to measure a differential (DIFF) analog input signal. 1. Connect the BNC cable to one of the AI <0..7> BNC connectors on the front panel. Do not connect anything to the corresponding AI <8..15> BNC connector below the AI <0..7> BNC connector you use. 2. Move the corresponding SE/DIFF switch to the DIFF position.
Chapter 2 Connecting Signals 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 on-device reference for the signal. To provide a return path for the instrumentation amplifier bias currents, floating sources must have a 10–100 kΩ resistor to AI GND on one input if DC-coupled, or both inputs if AC-coupled.
Chapter 2 Connecting Signals referenced single-ended (RSE) modes, refer to the E Series User Manual or the M Series User Manual. 4. Configure your software to measure this channel in RSE or NRSE mode. Figure 2-3 shows how single-ended AI signals are routed to the DAQ device. BNC-2090A Cable DAQ Device AI 0 AI 0 SE RSE NRSE AI GND AI SENSE DIFF RSE/NRSE Switch AI 8 AI 8 Figure 2-3. Analog Input Single-Ended Mode Moving the RSE/NRSE switch to RSE, connects the BNC shields to AI GND.
Chapter 2 Connecting Signals Refer to Chapter 3, Signal Conditioning, for information about building additional signal-conditioning circuitry, such as filters and attenuators, in the open-component positions.
Chapter 2 Connecting Signals Figure 2-4 shows how AO 0, AO 1, APFI 0, and PFI 0 signals are routed to the DAQ device. BNC-2090A Cable DAQ Device AO 0 AO 0 AO GND AO 1 AO 1 APFI 0 AI GND APFI 0 PFI 0 D GND PFI 0 Figure 2-4. Analog Output, APFI 0, and PFI 0 Refer to Chapter 3, Signal Conditioning, for information about building additional signal-conditioning circuitry.
Chapter 2 Connecting Signals Using the USER 1 and USER 2 BNC Connectors The USER 1 and USER 2 BNC connectors allow you to use a BNC connector for a digital or timing I/O signal of your choice. The USER 1 and USER 2 BNC connectors are routed (internal to the BNC-2090A) to the USER1 and USER2 spring terminals, as shown in Figure 2-5.
3 Signal Conditioning This chapter contains information about adding signal conditioning components to the BNC-2090A and signal conditioning examples for using the BNC-2090A with your DAQ device. Analog Input Signal Conditioning Each analog input signal has several open positions for passive signal conditioning components. The factory-default positions for the 0 Ω jumpers are the C and D positions of the input network, as shown in Figure 3-1.
Chapter 3 Signal Conditioning Figure 3-1 shows the onboard components for differential mode. COMMON SW9 DIFF SE AI 8 AI 0 BNC BNC R31 R32 B A AI GND Do Not Connect R33 D R30 Factory-Installed 0 Ω Jumpers C C10 E AI 8 R50 R51 G F AI GND AI 0 To Input Multiplexer of DAQ Device Figure 3-1. Channel 0 Differential Mode Onboard Components BNC-2090A User Manual 3-2 ni.
Chapter 3 Signal Conditioning Figure 3-2 shows the onboard components for single-ended mode. RSE AI GND COMMON SW9 DIFF AI SENSE SE AI 8 NRSE SW1 AI 0 BNC BNC R31 R32 B A AI GND R33 D R30 Factory-Installed 0 Ω Jumpers C C10 E AI 8 R50 R51 G F AI GND AI 0 To Input Multiplexer of DAQ Device Figure 3-2.
Chapter 3 Signal Conditioning Table 3-1 lists the different component positions for each channel. Table 3-1.
Chapter 3 Signal Conditioning Table 3-2 lists population options for passive signal conditioning components. Table 3-2.
Chapter 3 Signal Conditioning Output Amplitude (dB) 0 –20 –40 –60 –80 –100 0.01 0.1 1 10 100 Normalized Frequency (fc) 1000 10000 Figure 3-3. Normalized Frequency Response of Lowpass Filter Example When measuring low-frequency signals (about 4 Hz), if you have 400 Hz noise on your input signals, you can add a lowpass filter with a cutoff frequency of 4 Hz. The 400 Hz noise then attenuates by 40 dB. Notice that your 4 Hz signal also attenuates, by 3 dB.
Chapter 3 Signal Conditioning + R29(C) = 19.8 kΩ To DAQ Device AI 1 J10 C9(E) = 1 μF R26(D) = 19.8 kΩ – Figure 3-4. Lowpass Filter on Differential Channel 1 Figure 3-5 shows both the schematic and the component placement for a 4 Hz lowpass filter placed on single-ended input channel 1. Refer to the Installing Bias Resistors section for information about installing bias resistors. AI 1 R29(C) = 39.8 kΩ R49(F)= 1 μF To DAQ Device AI 1 J10 AI GND AI GND Figure 3-5.
Chapter 3 Signal Conditioning Output Amplitude (dB) 0 –20 –40 –60 –80 –100 0.0001 0.001 0.01 0.1 1 Normalized Frequency (fc) 10 100 Figure 3-6. Normalized Frequency Response of Highpass Filter Example When measuring high-frequency signals (about 50 kHz), if you have 50 Hz noise on your input signals, you can add a highpass filter with a cutoff frequency of 50 kHz. The 50 Hz noise then attenuates by 60 dB. Notice that your 50 kHz signal also attenuates, by 3 dB.
Chapter 3 Signal Conditioning Highpass filters generally exhibit poorer common-mode rejection characteristics than lowpass filters because capacitors are in the series input paths. Capacitors have poorer tolerances than resistors, and matching the input impedances is crucial for good common-mode rejection. Note Figure 3-7 shows both the schematic and the component placement for a 50 kHz highpass filter placed on differential input channel 1.
Chapter 3 Signal Conditioning Building Attenuators (Voltage Dividers) Attenuators or voltage dividers allow voltage measurements larger than the maximum input range of DAQ devices. For example, voltage signals in the ±20 V range can be measured by building a 2:1 voltage divider circuit. You can connect attenuators to the analog inputs of the BNC-2090A when the inputs from its DAQ device are in differential or single-ended mode. Caution Do not connect input voltages greater than 42.
Chapter 3 Signal Conditioning + R29(C) = 10 kΩ To DAQ Device AI 1 J10 C9(E) = 10 kΩ R26(D) = 10 kΩ – Figure 3-9. Attenuator for Use with Differential Inputs Figure 3-10 shows a resistor circuit for attenuating voltages at the single-ended inputs of the BNC-2090A. It also shows the placement of the resistors on the open-component positions for channel 1. AI 1 R29(C) = 20 kΩ AI 1 J10 R49(F) = 10 kΩ AI GND AI GND Figure 3-10.
Chapter 3 Signal Conditioning Notice that the input impedance for the channels employing voltage dividers circuit is reduced. In the differential example in Figure 3-9, the input impedance has been reduced to: 10 kΩ + 10 kΩ + 10 kΩ = 30 kΩ The reduced input impedance can cause loading errors for signal sources with large source impedance.
Chapter 3 Signal Conditioning Note Channels that use these filters have greater output impedance. This can result in loading errors if the connected load impedance is not much higher than the filter’s output impedance. Building Lowpass Filters Building lowpass filters for the analog output signals is the same as for the analog inputs. Refer to the Analog Input Signal Conditioning section for more detailed information about lowpass filters and how to calculate values for lowpass filters.
Chapter 3 Signal Conditioning Adding Signal Conditioning Components The BNC-2090A has open-component positions in the input paths into which you can insert resistors and capacitors for conditioning the 16 single-ended or eight differential analog input signals and the two analog output signals. You can also use the BNC-2090A in conjunction with other signal conditioning accessories. Figures 3-1 through 3-13 give examples using a specific channel.
Chapter 3 Signal Conditioning 2. Remove the two front panel screws. 3. Hold the front panel and slide the unit out of the metal case. 4. Install and/or remove components as necessary. Refer to the Soldering and Desoldering on the BNC-2090A section for more information. 5. Reassemble the BNC-2090A in reverse order. Soldering and Desoldering on the BNC-2090A Caution Use a low-wattage (20 to 30 W) soldering iron when soldering to the device. You should use only rosin-core, electronic-grade solder.
Chapter 3 Signal Conditioning + R29(C) R28(A) AI 1 To DAQ Device C9(E) AI GND J10 R27(B) = 100 kΩ R26(D) – Figure 3-15. Bias Return Resistor for DC-Coupled Floating Source on Channel 1 in DIFF Mode Figure 3-16 shows both the schematic and the component placement for an optional user-installed bias resistor, R35, between AI SENSE and AI GND. AI SENSE 2 R35 User-Installed Bias Resistor 1 AI GND Figure 3-16. User-Installed Bias Resistor between AI SENSE and AI GND BNC-2090A User Manual 3-16 ni.
A Specifications This appendix lists the specifications of the BNC-2090A. These specifications are typical at 25 °C unless otherwise specified. Analog Input Channels................................................. 8 differential (default), 16 single-ended Field connections ................................... 16 BNC connectors Signal conditioning ................................ 7 component positions per differential channel Analog Output Channels.................................................
Appendix A Specifications Power Requirement +5 VDC (±5%) provided by DAQ device Typical power consumed by BNC-2090A................................10 mA Maximum power available at +5 V spring terminal....................1 A (fuse-limited by host DAQ device) Physical Dimensions .............................................4.39 × 48.26 × 9.7 cm (1.73 × 19 × 3.82 in.) Weight ....................................................700 g (24.69 oz) I/O connector ..........................................
Appendix A Specifications Note For UL and other safety certifications, refer to the product label or visit ni.com/certification, search by model number or product line, and click the appropriate link in the Certification column.
B Frequently Asked Questions How does the BNC-2090A differ from the BNC-2090? The BNC-2090A is based on the BNC-2090. The main differences between these two accessories are listed in Table B-1. Table B-1.
Appendix B Frequently Asked Questions Can I use the SCXI resistor kit to build attenuators for my BNC-2090A? Yes. You can use the SCXI resistor kit, which consists of four high precision 249 Ω resistors, to build attenuators (voltage dividers) for the BNC-2090A. Refer to the Building Attenuators (Voltage Dividers) section of Chapter 3, Signal Conditioning, for more information about building attenuators for the BNC-2090A. Can I configure the BNC-2090A to measure current? Yes.
Technical Support and Professional Services C Visit the following sections of the National Instruments Web site at ni.com for technical support and professional services: • Support—Online technical support resources at ni.
Appendix C Technical Support and Professional Services • 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. Phone numbers for our worldwide offices are listed at the front of this manual. You also can visit the Worldwide Offices section of ni.
Index Symbols APFI diagram, 2-6 signals, 2-5 attenuators, 3-10 for use with differential inputs, 3-11 for use with single-ended inputs, 3-11 using SCXI resistor kit, B-2 +5V LED, 1-6 Numerics 100 Ω to digital ground jumper setting, 1-7 A B accessing digital/timing I/O signals from a BNC, 2-7 PCB, 3-14 signal conditioning components, 3-14 the shield ground jumper, 1-8 adding signal conditioning components, 3-14 AI.
Index digital/timing signals to a BNC, 2-7 PFI 0 signals, 2-5 signals, 2-1 single-ended analog input signals, 2-3 to E Series devices, 1-6 to M Series devices, 1-5 USER <1..2>, 2-7 connectors, USER <1..
Index enclosure back, 1-2 examples (NI resources), C-1 front panel and enclosure back, 1-2 highpass filter on differential channel 1, 3-9 highpass filter on single-ended channel 1, 3-9 installation, 1-3 lowpass filter on differential channel 1, 3-7 M Series device connections, 1-5 normalized frequency response of lowpass filter, 3-6 PFI 0 signals, 2-6 USER <1..2> BNC connections, 2-7 example, 2-7 DIFF mode.
Index I normalized frequency response of highpass filters, 3-8 NRSE mode.
Index T signal conditioning, 3-1 adding components, 3-14 analog input, 3-1 highpass filters, 3-7 lowpass filters, 3-5 lowpass filters normalized frequency response, 3-6 analog output, 3-12 channel component positions (table), 3-4 component population options (table), 3-5 signals analog input, 2-1 connecting, 2-2 analog output, 2-5 APFI, 2-5 connecting, 2-1 digital, 2-6 PFI, 2-5 timing, 2-7 single-ended mode analog input signal conditioning (figure), 3-3 attenuator use, 3-11 diagram, 2-4 measuring floating
