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CBIHWum.book Page 1 Thursday, October 29, 1998 1:56 PM
Computer-Based
Instruments
NI 5911 User Manual
Digital Oscilloscope for PCI
NI 5911 User Manual
October 1998 Edition
Part Number 322150A-01
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CBIHWum.book Page 2 Thursday, October 29, 1998 1:56 PM Internet Support E-mail: support@natinst.com FTP Site: ftp.natinst.com Web Address: http://www.natinst.com Bulletin Board Support BBS United States: 512 794 5422 BBS United Kingdom: 01635 551422 BBS France: 01 48 65 15 59 Fax-on-Demand Support 512 418 1111 Telephone Support (USA) Tel: 512 795 8248 Fax: 512 794 5678 International Offices Australia 03 9879 5166, Austria 0662 45 79 90 0, Belgium 02 757 00 20, Brazil 011 288 3336, Canada (On
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CBIHWum.book Page 3 Thursday, October 29, 1998 1:56 PM Important Information Warranty The NI 5911 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 warr
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CBIHWum.book Page iv Thursday, October 29, 1998 1:56 PM Conventions The following conventions are used in this manual: » The » symbol leads you through nested menu items and dialog box options to a final action. The sequence File»Page Setup»Options»Substitute Fonts directs you to pull down the File menu, select the Page Setup item, select Options, and finally select the Substitute Fonts options from the last dialog box. This icon to the left of bold italicized text denotes a note, which a
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CBIHWum.book Page v Thursday, October 29, 1998 1:56 PM Contents Chapter 1 Taking Measurements with the NI 5911 Connecting Signals ........................................................................................................1-1 Introduction to the VirtualBench-Scope Soft Front Panel.............................................1-2 Soft Front Panel Features ................................................................................1-3 Using the VirtualBench-SCOPE Soft Front Panel
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CBIHWum.book Page vi Thursday, October 29, 1998 1:56 PM Contents Appendix A Specifications Appendix B Digitizer Basics Appendix C Customer Communication Glossary Index Figures Figure 1-1. NI 5911 Connectors .............................................................................. 1-2 Figure 1-2. VirtualBench-Scope Soft Front Panel................................................... 1-3 Figure 1-3. Acquire Tab of VirtualBench-Scope Settings Dialog Box ................... 1-6 Figure 2-1. NI
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CBIHWum.book Page 1 Thursday, October 29, 1998 1:56 PM 1 Taking Measurements with the NI 5911 Thank you for buying a National Instruments 5911 digital oscilloscope with flexible resolution. The NI 5911 offers unsurpassed flexibility for performing measurements from DC to 100 MHz. Using the NI 5911 flexible resolution feature, you can choose the sampling rate and resolution best suited to your application. Detailed specifications for the NI 5911 are in Appendix A, Specifications. Connect
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CBIHWum.book Page 2 Thursday, October 29, 1998 1:56 PM Chapter 1 Taking Measurements with the NI 5911 CH0 PFI1 PFI2 (DIN) Figure 1-1. NI 5911 Connectors Introduction to the VirtualBench-Scope Soft Front Panel The VirtualBench-Scope soft front panel allows you to interactively control your NI 5911 as you would a desktop oscilloscope. The following sections explain how to make connections to your NI 5911 and take simple measurements using the VirtualBench-Scope soft front panel, as shown i
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CBIHWum.book Page 3 Thursday, October 29, 1998 1:56 PM Chapter 1 Taking Measurements with the NI 5911 1 2 8 3 4 7 5 6 1 Channel Display Selector 4 Trigger Setting Group 7 Zoom Controls 2 Channel Settings Selector 5 Vertical Slider 8 Graphics Display 3 Channel Settings 6 Main Control Bar Figure 1-2. VirtualBench-Scope Soft Front Panel Soft Front Panel Features The VirtualBench-Scope soft front panel has the following features: • Channel Display Selector—selects a waveform for display on the
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CBIHWum.book Page 4 Thursday, October 29, 1998 1:56 PM Chapter 1 Taking Measurements with the NI 5911 • Vertical Slider—adjusts the voltage offset for each channel. Use this slider when you want to adjust multiple waveforms in the graphics display. • Trigger Settings Group—controls the conditions required for signal acquisition; for example, whether to wait for a digital trigger before acquiring data or whether to acquire data in free-run mode (no triggering). • Main Control Bar Buttons
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CBIHWum.book Page 5 Thursday, October 29, 1998 1:56 PM Chapter 1 Taking Measurements with the NI 5911 Using the VirtualBench-SCOPE Soft Front Panel The following sections describe how to perform simple analog input measurements using the VirtualBench-SCOPE soft front panel. Acquiring Data When you launch VirtualBench-Scope, it operates in continuous run mode. You can start acquiring signals with VirtualBench-Scope by completing the following steps: 1. Connect a signal to Channel 0 of your
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CBIHWum.book Page 6 Thursday, October 29, 1998 1:56 PM Chapter 1 Taking Measurements with the NI 5911 Device Type Selector Device List Figure 1-3. Acquire Tab of VirtualBench-Scope Settings Dialog Box Note: When you launch VirtualBench-Scope, it automatically uses the settings of your previous VirtualBench-Scope session. 3. Enable the Ch 0 button in the Channel Selector group. Disable all other channels. 4. Click on AutoSetup on the main control bar. 5. Click on Run to start the acquisitio
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CBIHWum.book Page 1 Thursday, October 29, 1998 1:56 PM 2 Hardware Overview This chapter includes an overview of the NI 5911, explains the operation of each functional unit making up your NI 5911, and describes the signal connections. Figure 2-1 shows a block diagram of the NI 5911. Analog Input AC/DC Coupling Connector Protect/ Calibration PGA 1 MOhm A/D Converter Mux 100 MHz, 8-bit 1 kOhm Noise Shaper Calibration Generator Timing IO/ Reference Digital IO Memory Control Clock Connector Digi
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CBIHWum.book Page 2 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview Measurement Fundamentals The NI 5911 has a differential programmable gain input amplifier (PGIA) at the analog input. The purpose of the PGIA is to accurately interface to and scale the signal presented at the connector to the analog-to-digital converter (ADC) regardless of source impedance, source amplitude, DC biasing or common-mode noise voltages. Differential Input When measuring high dynamic range s
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CBIHWum.book Page 3 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview the cable impedances you use. As a result, most of the noise voltage occurs at the negative input of the PGIA where it is rejected, rather than in the positive input, where it would be amplified. Input Ranges To optimize the ADC resolution, you can select different gains for the PGIA. In this way, you can scale your input signal to match the full input range of the converter. The NI 5911 PGIA offers seven d
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CBIHWum.book Page 4 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview Input Bias The inputs of the PGIA typically draw an input bias current of 1 nA at 25° C. Attaching a device with a very high source impedance can cause an offset voltage to be added to the signal you measure, according to the formula R × 1 nA, where R is the external source impedance. For s s example, if the device you have attached to the NI 5911 has an output impedance of 10 kΩ, typically the offset volt
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CBIHWum.book Page 5 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview Oscilloscope Mode In the oscilloscope mode, the NI 5911 works as a conventional desktop oscilloscope. This mode is useful for displaying waveforms and for deriving waveform parameters such as slew rate, rise time, and settling time. The sample resolution in oscilloscope mode is 8 bits. The ADC converts at a constant rate of 100 MS/s, but you can choose to store only a fraction of these samples into memory a
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CBIHWum.book Page 6 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview Table 2-2. Available Sampling Rates and Corresponding Bandwidth in Flexible Resolution Mode Sampling Rate Resolution Bandwidth 12.5 MS/s 12 bits 4 MHz 5 MS/s 14 bits 2 MHz 2.5 MS/s 16 bits 800 kHz 1 MS/s 18 bits 400 kHz 500 MS/s 18 bits 200 kHz 200 MS/s 19 bits 80 kHz 100 MS/s 19 bits 40 kHz 50 MS/s 20 bits 20 kHz 20 MS/s 20 bits 8 kHz 10 MS/s 21 bits 4 kHz Like any other type of converter that uses noise shap
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CBIHWum.book Page 7 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview sampling rates, resolutions, and bandwidth for flexible resolution mode are shown in Table 2-2. During the acquisition, samples are stored in a circular buffer that is continually rewritten until a trigger is received. After the trigger is received, the NI 5911 continues to acquire posttrigger samples if you have specified a posttrigger sample count. The acquired samples are placed into onboard memory. T
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CBIHWum.book Page 8 Thursday, October 29, 1998 1:56 PM Chapter 2 Hardware Overview 3. The linearity of the ADC is calibrated using an internal sinewave generator as reference. 4. The time-to-digital converter used for RIS measurements is calibrated. Note Do not apply high-amplitude or high-frequency signals to the NI 5911 during internal calibration. For optimal calibration performance, disconnect the input signal from the NI 5911. External Calibration External calibration is used to calib
