National Instruments PCI-5911 User manual

Modular
Instrumentation
NI PCI-5911 User Manual
High-Speed Digitizer with Flex ADC
NI PCI-5911 User Manual
™
March 2003 Edition
Part Number 322150E-01

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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 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.
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accuracy. In the event that technical or typographical errors exist, National Instruments reserves the right to make changes to subsequent
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Compliance
FCC/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). All National Instruments (NI) products are FCC Class A products.
Depending on where it is operated, this Class A 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.
All Class A products display a simple warning statement of one paragraph in length regarding interference and undesired
operation. The FCC rules have restrictions regarding the locations where FCC Class A products can be operated.
Consult the FCC Web site at 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).
Changes or modifications not expressly approved by NI 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 user is required to correct the interference
at their own expense.
Canadian Department of Communications
This Class A digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe A respecte toutes les exigences du Règlement sur le matériel 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 hardware products except for those
bought from OEMs. In addition, DoCs are usually not provided if compliance is not required, for example 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
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* The CE marking Declaration of Conformity contains important supplementary information and instructions for the user or
installer.

©National Instruments Corporation v NI PCI-5911 User Manual
Contents
About This Manual
Conventions ...................................................................................................................vii
Related Documentation..................................................................................................viii
Safety Information .........................................................................................................viii
Chapter 1
Introduction
Installing the NI 5911 ....................................................................................................1-1
Connecting Signals ........................................................................................................1-1
Acquiring Data with the NI 5911 ..................................................................................1-3
Programmatically Controlling the NI 5911.....................................................1-3
Interactively Controlling the NI 5911 with the Scope Soft Front Panel .........1-4
Chapter 2
Hardware Overview
Differential Programmable Gain Input Amplifier (PGIA) ............................................2-1
Differential Input .............................................................................................2-1
Grounding Considerations ................................................................2-2
Input Ranges....................................................................................................2-3
Input Impedance ..............................................................................................2-3
Input Bias ..........................................................................................2-4
Input Protection ...............................................................................................2-4
AC Coupling....................................................................................................2-4
Conventional and Flexible Resolution Modes...............................................................2-5
Conventional Mode .........................................................................................2-5
Sampling Methods...........................................................................................2-5
Flexible Resolution Mode ...............................................................................2-6
How Flexible Resolution Works.......................................................2-6
Calibration .....................................................................................................................2-7
Self-Calibrating the NI 5911 ...........................................................................2-7
When Self-Calibration Is Needed....................................................................2-7
What Self-Calibration Does ............................................................................2-7
Why Warnings Occur During Acquisition........................................2-8
External Calibration.........................................................................................2-8
Triggering and Arming ..................................................................................................2-8
Analog Trigger Circuit ....................................................................................2-9
Trigger Holdoff ...............................................................................................2-10

Contents
NI PCI-5911 User Manual vi ni.com
Memory ......................................................................................................................... 2-10
Triggering and Memory Usage ....................................................................... 2-10
Multi-Record Acquisitions ............................................................................................ 2-11
RTSI Bus and Clock PFI ............................................................................................... 2-11
PFI Lines ......................................................................................................... 2-11
PFI Lines as Inputs ........................................................................... 2-12
PFI Lines as Outputs......................................................................... 2-12
Synchronization .............................................................................................. 2-12
Appendix A
Specifications
Appendix B
Technical Support and Professional Services
Glossary
Index

©National Instruments Corporation vii NI PCI-5911 User Manual
About This Manual
The NI 5911 User Manual provides information on installing, connecting
signals to, and acquiring data from your NI 5911 high-speed digitizer. This
manual includes an overview of the NI 5911 and explains the operation of
each functional unit of the NI 5911.
Conventions
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<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.
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.
bold Bold text denotes items that you must select or click in the software, such
as menu items and dialog box options. Bold text also denotes parameter
names.
italic 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.
monospace 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.

About This Manual
NI PCI-5911 User Manual viii ni.com
Related Documentation
The following documents contain information that you might find helpful
as you read this manual:
•Where to Start with Your NI Digitizer
•NI-SCOPE Software User Manual
•NI-SCOPE Instrument Driver Quick Reference Guide
You can download these documents from ni.com/manuals.
Safety Information
This section contains important safety information that you must follow
when installing and using the device.
Do not operate the device in a manner not specified in this document.
Misuse of the device can result in a hazard. You can compromise the safety
protection built into the device if the device is damaged in any way. If the
device is damaged, return it to National Instruments (NI) for repair.
Do not substitute parts or modify the device except as described in this
document. Use the device only with the chassis, devices, accessories, and
cables specified in the installation instructions. You must have all covers
and filler panels installed during operation of the device.
Do not operate the device in an explosive atmosphere or where there may
be flammable gases or fumes. If you must operate the device in such an
environment, it must be in a suitably rated enclosure.
If you need to clean the device, use a soft, nonmetallic brush. Make sure
that the device is completely dry and free from contaminants before
returning it to service.
Operate the device only at or below Pollution Degree 2. 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:
• Pollution Degree 1 means no pollution or only dry, nonconductive
pollution occurs. The pollution has no influence.
• Pollution Degree 2 means that only nonconductive pollution occurs in
most cases. Occasionally, however, a temporary conductivity caused
by condensation must be expected.

About This Manual
©National Instruments Corporation ix NI PCI-5911 User Manual
• Pollution Degree 3 means that conductive pollution occurs, or dry,
nonconductive pollution occurs that becomes conductive due to
condensation.
You must insulate signal connections for the maximum voltage for which
the device is rated. Do not exceed the maximum ratings for the device. Do
not install wiring while the device is live with electrical signals. Do not
remove or add connector blocks when power is connected to the system.
Avoid contact between your body and the connector block signal when hot
swapping devices. Remove power from signal lines before connecting them
to or disconnecting them from the device.
Operate the device at or below the installation category1marked on the
hardware label. Measurement circuits are subjected to working voltages2
and transient stresses (overvoltage) from the circuit to which they are
connected during measurement or test. Installation categories establish
standard impulse withstand voltage levels that commonly occur in
electrical distribution systems. The following is a description of installation
categories:
• Installation Category I is for measurements performed on circuits not
directly connected to the electrical distribution system referred to as
MAINS3voltage. This category is for measurements of voltages from
specially protected secondary circuits. Such voltage measurements
include signal levels, special equipment, limited-energy parts of
equipment, circuits powered by regulated low-voltage sources, and
electronics.
• Installation Category II is for measurements performed on circuits
directly connected to the electrical distribution system. This category
refers to local-level electrical distribution, such as that provided by a
standard wall outlet (for example, 115 AC voltage for U.S. or 230 AC
voltage for Europe). Examples of Installation Category II are
measurements performed on household appliances, portable tools, and
similar devices.
• Installation Category III is for measurements performed in the building
installation at the distribution level. This category refers to
measurements on hard-wired equipment such as equipment in fixed
installations, distribution boards, and circuit breakers. Other examples
are wiring, including cables, bus bars, junction boxes, switches, socket
1 Installation categories, also referred to as measurement categories, are defined in electrical safety standard IEC 61010-1.
2 Working voltage is the highest rms value of an AC or DC voltage that can occur across any particular insulation.
3 MAINS is defined as a hazardous live electrical supply system that powers equipment. Suitably rated measuring circuits may
be connected to the MAINS for measuring purposes.

About This Manual
NI PCI-5911 User Manual x ni.com
outlets in the fixed installation, and stationary motors with permanent
connections to fixed installations.
• Installation Category IV is for measurements performed at the primary
electrical supply installation (<1,000 V). Examples include electricity
meters and measurements on primary overcurrent protection devices
and on ripple control units.

©National Instruments Corporation 1-1 NI PCI-5911 User Manual
1
Introduction
Thank you for buying an NI PCI-5911 digitizer, featuring the Flex ADC for
variable speed and resolution. This chapter contains information on
installing, connecting signals to, and acquiring data from the NI 5911
Installing the NI 5911
Installation involves the following main steps:
1. Install the NI-SCOPE driver software. You use this driver to write
programs to control the NI 5911 in different application development
environments (ADEs). Installing NI-SCOPE also allows you to
interactively control the NI 5911 with the Scope Soft Front Panel.
2. Install the NI 5911.
For step-by-step instructions for installing both NI-SCOPE and the
NI 5911, refer to the Where to Start with Your NI Digitizer document.
For multiple-device considerations, refer to the Operating Environment
section of Appendix A, Specifications.
Connecting Signals
Figure 1-1 shows the front panel of the NI 5911. The front panel contains
three connectors—a BNC connector, an SMB connector, and a 9-pin
mini-circular DIN connector. Figure 1-2 shows the 9-pin mini-circular DIN
connector.
The BNC connector is for attaching the analog input signal you want to
measure. The BNC connector is analog input channel 0. To minimize noise,
do not allow the shell of the BNC cable to touch or lie near the metal of the
computer chassis. The SMB connector is used for external triggers and for
generating a probe compensation signal. The SMB connector is labeled
PFI 1. The DIN connector provides access to an additional external trigger
line. The DIN connector can be used to access PFI 2.

Chapter 1 Introduction
NI PCI-5911 User Manual 1-2 ni.com
Note The +5 V signal is fused at 1.1 A. However, NI recommends limiting the current
from this pin to 30 mA. The fuse is self-resetting.
Figure 1-1. NI 5911 Connectors
CH 0
PFI 1
PFI 2
(DIN)

Chapter 1 Introduction
©National Instruments Corporation 1-3 NI PCI-5911 User Manual
Figure 1-2. 9-Pin Mini-Circular DIN Connector
Acquiring Data with the NI 5911
You can acquire data either programmatically—by writing an application
for the NI 5911—or interactively with the Scope Soft Front Panel.
Programmatically Controlling the NI 5911
To help you get started programming the NI 5911, NI-SCOPE includes
examples that you can use or modify.
You can find examples for the following ADEs in these locations:
• LabVIEW—Go to Program Files\National Instruments\
LabVIEW\Examples\Instr\niScopeExamples\.
• LabWindows™/CVI™, C, and Visual Basic with
Windows 2000/NT—Go to vxipnp\winnt\Niscope\Examples\.
• LabWindows/CVI, C, and Visual Basic with Windows 98/95—Go to
vxipnp\win95\Niscope\Examples\c\.
For information on using NI-SCOPE to programmatically control your
digitizer, refer to the NI-SCOPE Software User Manual. Another resource
is the NI-SCOPE Instrument Driver Quick Reference Guide, which
contains abbreviated information on the most commonly used functions
and LabVIEW VIs. For more detailed function reference help, refer to the
1 +5 V (Fused)
2GND
3 Reserved
4Reserved
5Reserved
6PFI2
7 Reserved
8 Reserved
9 Reserved
43 56
789
12

Chapter 1 Introduction
NI PCI-5911 User Manual 1-4 ni.com
NI-SCOPE Function Reference Help, located at Start»Programs»
National Instruments»NI-SCOPE. For more detailed VI help,
use LabVIEW context-sensitive help (Help»Show Context Help) or the
NI-SCOPE VI Reference Help, located at Start»Programs»National
Instruments»NI-SCOPE.
Interactively Controlling the NI 5911 with the Scope Soft Front Panel
The Scope Soft Front Panel allows you to interactively control the NI 5911
as you would a desktop oscilloscope. To launch the Scope Soft Front Panel,
select Start»Programs»National Instruments»NI-SCOPE»
NI-SCOPE Soft Front Panel. Refer to the Scope Soft Front Panel Help
for instructions on configuring the Scope Soft Front Panel for your specific
application.
Note Press <F1> while the Scope Soft Front Panel is running to access the Scope Soft
Front Panel Help.

©National Instruments Corporation 2-1 NI PCI-5911 User Manual
2
Hardware Overview
This chapter includes an overview of the NI 5911, explains the operation of
each functional unit making up the NI 5911, and describes the signal
connections. Figure 2-1 shows a block diagram of the NI 5911.
Figure 2-1. NI 5911 Block Diagram
Differential Programmable Gain Input Amplifier (PGIA)
The analog input of the NI 5911 is equipped with a differential
programmable gain input amplifier. The PGIA accurately interfaces to and
scales the signal presented to the ADC regardless of source impedance,
source amplitude, DC biasing, or common-mode noise voltages.
Differential Input
When measuring high dynamic range signals, ground noise is often a
problem. The PGIA of the NI 5911 allows you to make noise-free signal
measurements. The PGIA differential amplifier efficiently rejects any
noise present on the ground signal. Internal to the PGIA, the signal
Protect/
Calibration
Mux
Calibration
Generator
PGIA
Noise
Shaper
Reference
Clock
Data
A/D Converter
100 MHz, 8-Bit
Digital Signal
Processor
Digital I/O
Connector
Analog Input
Connector
AC/DC Coupling
Capture
Memory
Timing I/O,
Memory Control

Chapter 2 Hardware Overview
NI PCI-5911 User Manual 2-2 ni.com
presented at the negative input is subtracted from the signal presented at the
positive input. As shown in Figure 2-2, this subtraction removes ground
noise from the signal. The inner conductor of the BNC is V+. The outer
shell is V–.
Figure 2-2. Signal Noise-Free Measurements
Grounding Considerations
The path for the positive signal has been optimized for speed and linearity.
You should always apply signals to the positive input and ground to the
negative input. Reversing the inputs results in higher distortion and lower
bandwidth.
The negative input of the amplifier is grounded to PC ground through a
10 kΩresistor. The PGIA is therefore referenced to ground, so it is not
necessary to make any external ground connections. If the device you
connect to the NI 5911 is already connected to ground, ground-loop noise
voltages may be induced into your system. Notice that in most of these
situations, the 10 kΩresistance to PC ground is normally much higher than
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.
+
–
Vout
V+
Input Signal
Ground Noise
V– PGIA

Chapter 2 Hardware Overview
©National Instruments Corporation 2-3 NI PCI-5911 User Manual
Input Ranges
To optimize the ADC resolution, you can select different gains for the
PGIA so that you can scale your input signal to match the full input range
of the converter. The NI 5911 PGIA offers seven input ranges, from ±0.1 V
to ±10 V, as shown in Table 2-1.
Note If you try to acquire a signal below the set input range, the sensitive front-end
components of the NI 5911 may become unstable and begin returning invalid data. To
return the digitizer to a stable configuration, switch to the maximum input range setting and
acquire an AC coupled or 0 V signal.
The input stage of the NI 5911 requires a settling time that depends on
which vertical range you are switching from and which vertical range you
are switching to. However, allowing for a delay of 250 ms between
configuring the input stage and starting the acquisition guarantees proper
settling.
Input Impedance
The input impedance of the NI 5911 PGIA is 1 MΩbetween the positive
and negative input, ±2% depending on input capacitance. The output
impedance of the device connected to the NI 5911 and the input impedance
of the NI 5911 form an impedance divider, which attenuates the input
signal according to the following formula:
Table 2-1. Input Ranges for the NI 5911
Range Input Protection Threshold
±10 V ±10 V
±5 V ±5 V
±2 V ±5 V
±1 V ±5 V
±0.5 V ±5 V
±0.2 V ±5 V
±0.1 V ±5 V
Vm
VsRin
RsRin +
--------------------=

Chapter 2 Hardware Overview
NI PCI-5911 User Manual 2-4 ni.com
where Vmis the measured voltage, Vsis the source voltage, Rsis the external
source impedance, and Rin is the input impedance.
If the device you are measuring has a very large output impedance, your
measurements will be affected by this impedance divider. For example,
if the device has 1 MΩ output impedance, your measured signal is one-half
of the actual signal value.
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 measured, according to
the formula Rs× 1 nA, where Rsis the external source impedance. For
example, if the device you have attached to the NI 5911 has an output
impedance of 10 kΩ, typically the offset voltage is 10 µV (10 kΩ×1nA).
Input Protection
The NI 5911 features input-protection circuits that protect both the positive
and negative analog inputs from damage from AC and DC signals up to
±42 V.
If the voltage at one of these inputs exceeds a threshold voltage, Vtr, the
input clamps to Vtr and a resistance of 100 kΩis inserted in the path to
minimize input currents to a nonharmful level.
The protection voltage, Vtr,is input range dependent, as shown in Table 2-1.
AC Coupling
When you measure a small AC signal on top of a large DC component, you
can use AC coupling. AC coupling rejects any DC component in your
signal before it enters into the PGIA. Activating AC coupling inserts a
capacitor in series with the input impedance. You can select input coupling
through software.
When changing the coupling on the digitizer, the input stage takes a finite
amount of time to settle. When switching from AC to DC coupling, the
settling time is approximately 0.5 ms. When switching from DC to
AC coupling, the returned data is accurate several time constants after
switching to AC. The NI 5911 has a time constant value of 68 ms. The
equation 1 – e–t/T, where Tis the time constant, gives the percentage that the
original signal has settled after time t. Generally, six time constants is
enough time between switching to AC coupling and starting the acquisition

Chapter 2 Hardware Overview
©National Instruments Corporation 2-5 NI PCI-5911 User Manual
to allow an 8-bit digitizer to acquire accurate data. However, the NI 5911 in
flexible resolution mode is much more precise and thus requires a greater
number of time constants of settling time to achieve the desired precision.
Refer to Appendix A, Digitizer Basics, of the NI-SCOPE Software User
Manual,for more information on input coupling.
Conventional and Flexible Resolution Modes
In conventional mode, the NI 5911 works as a conventional desktop
oscilloscope, acquiring data at 100 MS/s with a vertical resolution of 8 bits.
This mode is useful for displaying waveforms and for deriving waveform
parameters such as slew rate, rise time, and settling time.
Flexible resolution mode differs from conventional mode in two ways: it
has higher resolution (sampling rate dependent), and the signal bandwidth
is limited to provide antialiasing protection. Flexible resolution mode is
useful for spectral analysis, distortion analysis, and other measurements for
which high resolution is crucial.
Conventional Mode
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 at a lower rate. This
lower rate allows you to store waveforms using fewer data points and
decreases the burden of storing, analyzing, and displaying the waveforms.
If you need faster sampling rates, you can use Random Interleaved
Sampling (RIS) to effectively increase the sampling rate to 1 GS/s for
repetitive waveforms.
In conventional mode, all signals up to 100 MHz are passed to the ADC.
You must ensure that your signal is band-limited to prevent aliasing.
Aliasing and other sampling terms are described more thoroughly in the
NI-SCOPE Software User Manual.
Sampling Methods
Two sampling methods are available in conventional mode: real-time
sampling and random interleaved sampling (RIS). Using real-time
sampling, you can acquire data at a rate of 100/nMS/s,where nis a number
from 1 to 224. RIS sampling can be used on repetitive signals to effectively
extend the sampling rate above 100 MS/s. In RIS mode, you can sample at
rates of 100 × nMS/s, where nis a number from 2 to 10.

Chapter 2 Hardware Overview
NI PCI-5911 User Manual 2-6 ni.com
Flexible Resolution Mode
Table 2-2 shows the relationship between the available sampling rates,
resolution, and the corresponding bandwidth for flexible resolution mode.
Like any other type of converter that uses noise shaping to enhance
resolution, the frequency response of the converter is only flat to its
maximum useful bandwidth. The NI 5911 has a bandwidth of 4 MHz.
Beyond this frequency, there is a span where the converter acts resonant
and where a signal is amplified before being converted. These signals are
attenuated in the subsequent digital filter to prevent aliasing. However,
if the applied signal contains major signal components in this frequency
range, such as harmonics or noise, the converter may overload and signal
data will be invalid. In this case, you receive an overload warning. You must
then either select a higher input range or attenuate the signal.
How Flexible Resolution Works
The ADC can be sourced through a noise shaping circuit that moves
quantization noise on the output of the ADC from lower frequencies to
higher frequencies. A digital lowpass filter applied to the data removes all
but a fraction of the original shaped quantization noise. The signal is then
resampled to a lower sampling frequency and a higher resolution. Flexible
resolution provides antialiasing protection due to the digital lowpass filter.
Table 2-2. Available Sampling Rates and Corresponding Bandwidth
in Flexible Resolution Mode
Sampling Rate Resolution Bandwidth
12.5 MS/s 11 bits 3.75 MHz
5 MS/s 14 bits 2 MHz
2.5 MS/s 15.5 bits 1 MHz
1 MS/s 17.5 bits 400 kHz
500 kS/s 18 bits 200 kHz
200 kS/s 18.5 bits 80 kHz
100 kS/s 19 bits 40 kHz
50 kS/s 19.5 bits 20 kHz
20 kS/s 20.5 bits 8 kHz
10 kS/s 21 bits 4 kHz