National Instruments BNC-208X Series User manual

© Copyright 1991, 1994 National Instruments Corporation.
All Rights Reserved.
BNC-208X Series
User Manual
Analog BNC Breakout Boards
September 1993 Edition
Part Number 320407-01

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Limited Warranty
The BNC-208X Series boards are 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 manual is accurate. The document has been
carefully reviewed for technical accuracy. In the event that technical or typographical errors exist, National
Instruments 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
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information contained in it.
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© National Instruments Corporation v BNC-208X Series User Manual
Preface
This manual describes the electrical and mechanical aspects of the BNC-2080 and
BNC-2081 boards and contains information about installing and making connections to the boards.
The BNC-208X Series boards are analog breakout boards with BNC-style connectors. These
breakout boards connect to the National Instruments multifunction data acquisition boards for the
IBM PC/XT/AT, Personal System/2, and compatible computers, and Macintosh NuBus computers.
Organization of This Manual
The BNC-208X Series User Manual is organized as follows:
• Chapter 1, Introduction, describes the BNC-208X Series boards; lists the contents of your
BNC-2080 and BNC-2081 kits; describes the optional equipment, signal conditioning
accessories, and software support; and explains how to unpack your BNC-208X Series board.
• Chapter 2, BNC-2080 Board,describes the BNC-2080 board in detail, including its function,
specifications, compatibility, connection, mounting, and application notes.
• Chapter 3, BNC-2081 Board, describes the BNC-2081 board in detail, including its function,
specifications, compatibility, connection, mounting, and application notes.
• Chapter 4, Installation and Connections, explains how to install and make connections to the
BNC-208X Series boards.
• TheCustomer Communication appendix contains forms you can use to request help from
National Instruments or to comment on our products.
• The Index contains an alphabetical list of key terms and topics in this manual, including the
page where you can find each one.
Conventions Used in This Manual
The following conventions are used in this manual:
italic Italic text denotes emphasis, a cross reference, or an introduction to a key
concept.
Lab board Lab board refers to the Lab-PC, Lab-PC+, Lab-NB, and Lab-LC boards.
Macintosh NuBus Macintosh NuBus refers to the Macintosh NuBus family of computers.
MIO-16 MIO-16 refers to the AT-MIO-16, AT-MIO-16D, AT-MIO-16F-5,
AT-MIO-16X, MC-MIO-16, NB-MIO-16, NB-MIO-16X, and
PC-LPM-16 boards.

Preface
BNC-208X Series User Manual vi © National Instruments Corporation
PC PC refers to PC/XT/AT/EISA and IBM PS/2 computers.
SC-205X SC-205X refers to the SC-2050, SC-2051, SC-2052, and SC-2053 boards.
SC-206X SC-206X refers to the SC-2060, SC-2061, and SC-2062 boards.
SC-207X SC-207X refers to the SC-2070, SC-2071, and SC-2072 boards.
Abbreviations
The following metric system prefixes are used with abbreviations for units of measure in this
manual:
Prefix Meaning Value
µ- micro- 10-6
m- milli- 10-3
k- kilo- 103
M- mega- 106
The following abbreviations are used in this manual:
A amperes
C Celsius
dB decibels
°degrees
F farads
fccutoff frequency
Hz hertz
in. inches
m meters
Ωohms
% percent
πpi
V volts
W watts
Acronyms
The following acronyms are used in this manual:
AC alternating current
CMRR common-mode rejection ratio
DC direct current
DGND digital ground
DIFF differential input
I/O input/output
LED light-emitting diode
NRSE nonreferenced single-ended input
RSE referenced single-ended input
VDC volts direct current

Preface
© National Instruments Corporation vii BNC-208X Series User Manual
Related Documentation
The following National Instruments documents contain information that you may find helpful as
you read this manual:
•SC-205X Series User Manual (part number 320385-01)
•SC-206X Series User Manual (part number 320200-01)
•SC-207X Series User Manual (part number 320239-01)
The following National Instruments documents may also be helpful to you depending on the type of
system you are using with your BNC-208X Series boards:
• Macintosh NuBus users
-NB-MIO-16X User Manual (part number 320157-01)
-NB-MIO-16 User Manual (part number 320295-01)
-Lab-NB User Manual (part number 320174-01)
• IBM PC/XT/AT users
-AT-MIO-16F-5 User Manual (part number 320266-01)
-AT-MIO-16 User Manual (part number 320476-01)
-Lab-PC User Manual (part number 320205-01)
-Lab-PC+ User Manual (part number 320502-01)
-PC-LPM-16 User Manual (part number 320287-01)
• IBM PS/2 Micro Channel users
-MC-MIO-16 User Manual (part number 320130-01)
Customer Communication
National Instruments wants to receive your comments on our products and manuals. We are
interested in the applications you develop with our products, and we want to help if you have
problems with them. To make it easy for you to contact us, this manual contains comment and
configuration forms for you to complete. These forms are in the appendix at the end of this manual.

© National Instruments Corporation ix BNC-208X Series User Manual
Contents
Chapter 1
Introduction .........................................................................................................................1-1
What Your Kit Should Contain......................................................................................1-3
Optional Equipment.......................................................................................................1-3
Signal Conditioning Accessories...................................................................................1-4
Software Support............................................................................................................1-5
Unpacking......................................................................................................................1-5
Chapter 2
BNC-2080 Board ................................................................................................................2-1
Power Connections ........................................................................................................2-3
Analog Input...................................................................................................................2-3
Shield Ground................................................................................................................2-5
Fuse and Power LED.....................................................................................................2-6
Digital and Timing Signals............................................................................................2-6
Specifications.................................................................................................................2-6
Analog Input ......................................................................................................2-6
Power Requirements..........................................................................................2-7
Physical..............................................................................................................2-7
Operating Environment......................................................................................2-7
Storage Environment..........................................................................................2-7
Board-to-Board Cabling.................................................................................................2-7
Mounting........................................................................................................................2-9
Application Notes ..........................................................................................................2-9
Soldering and Desoldering on the BNC-2080 Board.........................................2-9
Channel Configurations.....................................................................................2-9
MIO-16 Analog Input............................................................................2-9
Connecting Nonreferenced (or Floating) Signal Sources..................................2-13
Differential Inputs..................................................................................2-13
Single-Ended Inputs...............................................................................2-14
Connecting Ground-Referenced Signal Sources................................................2-15
Differential Inputs..................................................................................2-15
Single-Ended Inputs...............................................................................2-15
Building Lowpass Filters...................................................................................2-15
Building Highpass Filters...................................................................................2-17
Building Attenuators (Voltage Dividers)...........................................................2-20
PC-LPM-16............................................................................................2-22
MIO-16 Analog Output..........................................................................2-23
Chapter 3
BNC-2081 Board.................................................................................................................3-1
Analog Input ..................................................................................................................3-2
Shield Ground................................................................................................................3-4
Fuse and Power LED.....................................................................................................3-5
Digital and Timing Signals............................................................................................3-5

Contents
BNC-208X Series User Manual x © National Instruments Corporation
Specifications.................................................................................................................3-5
Analog Input ......................................................................................................3-5
Power Requirements..........................................................................................3-5
Physical..............................................................................................................3-6
Operating Environment......................................................................................3-6
Storage Environment..........................................................................................3-6
Board-to-Board Cabling.................................................................................................3-6
Mounting........................................................................................................................3-8
Application Notes ..........................................................................................................3-8
Soldering and Desoldering on the BNC-2081 Board.........................................3-8
Connecting Nonreferenced (or Floating) Signal Sources..................................3-8
Connecting Ground-Referenced Signal Sources................................................3-8
Building Lowpass Filters...................................................................................3-9
Building Highpass Filters...................................................................................3-11
Building Attenuators (Voltage Dividers)...........................................................3-12
Lab Board Analog Output..............................................................................................3-14
Chapter 4
Installation and Connections..........................................................................................4-1
Hardware Installation.....................................................................................................4-1
Hardware Installation for the BNC-2080 and the BNC-2081............................4-1
Installing the SC-205X Series Cable Adapter Boards.......................................4-2
Installing the SC-207X General-Purpose Termination Breadboards.................4-2
Rack Mounting...................................................................................................4-2
External Power Connection (If Necessary)........................................................4-5
BNC-208X Series Board Connection................................................................4-6
Signal Connections ........................................................................................................4-7
Ribbon-Cable Connectors..................................................................................4-7
Rack-Mount Chassis Cover Attachment............................................................4-7
Appendix
Customer Communication...............................................................................................A-1
Index..................................................................................................................................Index-1
Figures
Figure 1-1. BNC-2080 Board Directly Connected to an MIO-16 Board............................1-2
Figure 1-2. BNC-208X, SC-207X, SC-206X, and SC-205X Series Boards
Connected to an MIO-16 Board.......................................................................1-2
Figure 2-1. BNC-2080 Analog Breakout Board..................................................................2-1
Figure 2-2. BNC-2080 Board Parts Locator Diagram.........................................................2-2
Figure 2-3. Onboard Equivalent Circuit for DIFF Mode....................................................2-4
Figure 2-4. W2 Jumper Settings..........................................................................................2-5
Figure 2-5. Direct Connection between an MIO-16 Board and the BNC-2080 Board.......2-8

Contents
© National Instruments Corporation xi BNC-208X Series User Manual
Figure 2-6. Connection between an MIO-16 Board, the BNC-2080 Board, and
the SC-2070/72 Board or the MIO-16, and the BNC-2080 and
SC-206X Series Boards via the SC-2050 Board..............................................2-8
Figure 2-7. Switch Configurations for Differential Mode or Single-Ended Mode.............2-10
Figure 2-8. W1 Ground Reference Jumper.........................................................................2-10
Figure 2-9. BNC-2080 Switch Configurations for an MIO-16 Configured in
DIFF Mode (Factory Default Setting)..............................................................2-11
Figure 2-10. BNC-2080 Switch Configurations for an MIO-16 Configured in
RSE and NRSE Modes.....................................................................................2-12
Figure 2-11. Bias Return Resistor for DC-Coupled Floating Source on Channel 1
in DIFF Mode...................................................................................................2-14
Figure 2-12. Normalized Frequency Response of Lowpass Filter........................................2-16
Figure 2-13. Lowpass Filter on Differential Channel 1........................................................2-17
Figure 2-14. Normalized Frequency Response of Highpass Filter.......................................2-18
Figure 2-15. Highpass Filter on Differential Channel 1........................................................2-19
Figure 2-16. Attenuator for Use with Differential Inputs......................................................2-21
Figure 2-17. Switch Configurations for SE Mode (PC-LPM-16).........................................2-22
Figure 2-18. Ground Reference Jumper Position for Use with the PC-LPM-16..................2-23
Figure 2-19. Analog Output Schematic for DACs, DAC0 OUT Shown.............................2-23
Figure 3-1. BNC-2081 Analog Breakout Board..................................................................3-1
Figure 3-2. BNC-2081 Board Parts Locator Diagram.........................................................3-2
Figure 3-3. Onboard Equivalent Circuit..............................................................................3-3
Figure 3-4. W1 Jumper Settings..........................................................................................3-4
Figure 3-5. Direct Connection between a Lab Board and the BNC-2081 Board................3-7
Figure 3-6. Connection between a Lab Board, the BNC-2081, and the SC-2071 Board,
or the Connection between a Lab Board, the BNC-2081 and the SC-206X
Series Board, via the SC-2053 Board...............................................................3-7
Figure 3-7. Normalized Frequency Response of Lowpass Filter........................................3-9
Figure 3-8. Lowpass Filter on Channel 1............................................................................3-10
Figure 3-9. Normalized Frequency Response of Highpass Filter.......................................3-11
Figure 3-10. Highpass Filter on Channel 1 ...........................................................................3-12
Figure 3-11. Attenuator for Use with BNC-2081 Board Inputs............................................3-13
Figure 3-12. DAC0 OUT Schematic.....................................................................................3-14
Figure 3-13. Analog Output Schematic for DACs, DAC0 OUT Shown.............................3-14
Figure 4-1. Mounting Locations for the BNC-208X Series Board and SC-207X
Series Board......................................................................................................4-3
Figure 4-2. Mounting Locations for the BNC-208X Series Board and SC-205X
Series Board or SC-206X Series Board............................................................4-3
Figure 4-3. Attaching a Mountable Board to the Chassis ...................................................4-4
Figure 4-4. Double-Height Mounting..................................................................................4-5
Figure 4-5. Connections between Data Acquisition Boards and BNC-208X
Series Boards and between SC-205X Series Boards and BNC-2080
and BNC-2081 Boards......................................................................................4-6