Tektronix Keithley KUSB-3116 User's Manual User manual
KUSB-3116
User’s Manual
KUSB3116-900-01 Rev. A / January 2005
www.keithley.com
A GR
EATER MEASURE OF CONFIDENCE
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 3 years from
date of shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries,
diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio.
You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse
of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN
ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE
POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO:
COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON,
OR DAMAGE TO PROPERTY.
A G R E A T E R M E A S U R E O F C O N F I D E N C E
Keithley Instruments, Inc.
Corporate Headquarters • 28775 Aurora Road • Cleveland, Ohio 44139
440-248-0400 • Fax: 440-248-6168 • 1-888-KEITHLEY (534-8453) • www.keithley.com
12/04
KUSB-3116
User’s Manual
©2005, Keithley Instruments, Inc.
All rights reserved.
First Printing, January 2005
Cleveland, Ohio, U.S.A.
Document Number: KUSB3116-900-01A Rev. A
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released
between Revisions, contain important change information that the user should incorporate immediately into the manual.
Addenda are numbered sequentially. When a new Revision is created, all Addenda associated with the previous Revision
of the manual are incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this
print history page.
Revision A (Document Number KUSB3116-900-01A) ...................................................................... January 2005
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.
Safety Precautions
The following safety precautions should be observed before using
this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read and follow all installation,
operation, and maintenance information carefully before using the
product. Refer to the manual for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product may be impaired.
The types of product users are:
Responsible body is the individual or group responsible for the use
and maintenance of equipment, for ensuring that the equipment is
operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be
trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with
hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating properly, for example, setting the line voltage or replacing consumable materials. Maintenance procedures
are described in the manual. The procedures explicitly state if the
operator may perform them. Otherwise, they should be performed
only by service personnel.
Service personnel are trained to work on live circuits, and perform
safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that
are rated Measurement Category I and Measurement Category II, as
described in the International Electrotechnical Commission (IEC)
Standard IEC 60664. Most measurement, control, and data I/O signals are Measurement Category I and must not be directly connected to mains voltage or to voltage sources with high transient overvoltages. Measurement Category II connections require protection
for high transient over-voltages often associated with local AC
mains connections. Assume all measurement, control, and data I/O
connections are for connection to Category I sources unless otherwise marked or described in the Manual.
Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures.
The American National Standards Institute (ANSI) states that a
shock hazard exists when voltage levels greater than 30V RMS,
42.4V peak, or 60VDC are present. A good safety practice is to ex-
pect that hazardous voltage is present in any unknown circuit
before measuring.
Operators of this product must be protected from electric shock at
all times. The responsible body must ensure that operators are prevented access and/or insulated from every connection point. In
some cases, connections must be exposed to potential human contact. Product operators in these circumstances must be trained to
protect themselves from the risk of electric shock. If the circuit is
capable of operating at or above 1000 volts, no conductive part of
the circuit may be exposed.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit
fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.
When installing equipment where access to the main power cord is
restricted, such as rack mounting, a separate main input power disconnect device must be provided, in close proximity to the equipment and within easy reach of the operator.
For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge
any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always
make measurements with dry hands while standing on a dry, insulated
surface capable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or
switching card.
When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.
Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a
lid interlock.
5/03
If a screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.
!
The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.
The symbol indicates a connection terminal to the equipment
frame.
The WARNING heading in a manual explains dangers that might
result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and
all test cables.
To maintain protection from electric shock and fire, replacement
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean an instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill on
the instrument. Products that consist of a circuit board with no case
or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected,
the board should be returned to the factory for proper cleaning/servicing.
Table of Contents
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Intended Audience. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
How this Manual is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Conventions Used in this Manual . . . . . . . . . . . . . . . . . . . . . . . . . xii
Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
Where To Get Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Chapter 1: Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Chapter 2: Principles of Operation . . . . . . . . . . . . . . . . . . . . 5
Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Input Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Analog Input Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Specifying a Single Analog Input Channel . . . . . . . . . . . 9
Specifying One or More Analog Input Channels . . . . . . 9
Specifying the Digital Input Port in the Analog
Input Channel-Gain List . . . . . . . . . . . . . . . . . . . . . . . . 10
Specifying Counter/Timers in the Analog
Input Channel-Gain List . . . . . . . . . . . . . . . . . . . . . . . . 11
Performing Dynamic Digital Output Operations . . . . 13
Input Ranges and Gains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Specifying the Gain for a Single Channel . . . . . . . . . . . 15
Specifying the Gain for One or More Channels . . . . . . 15
Input Sample Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 16
vii
Contents
Analog Input Conversion Modes . . . . . . . . . . . . . . . . . . . . . . 17
Continuous Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Triggered Scan Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Internally Retriggered Scan Mode . . . . . . . . . . . . . . 20
Externally Retriggered Scan Mode. . . . . . . . . . . . . . 21
Input Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Data Format and Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Output Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Analog Output Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Specifying a Single Analog Output Channel . . . . . . . . 27
Specifying Multiple Analog Output Channels
and/or the Digital Output Port . . . . . . . . . . . . . . . . . . 27
Output Ranges and Gains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Output Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Output Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Output Conversion Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Continuously Paced Analog Output . . . . . . . . . . . . . . . 31
Waveform Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Data Format and Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Digital I/O Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Operation Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Counter/Timer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
C/T Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
C/T Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Gate Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Pulse Output Types and Duty Cycles . . . . . . . . . . . . . . . . . . 41
viii
Counter/Timer Operation Modes . . . . . . . . . . . . . . . . . . . . . 42
Event Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Up/Down Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Frequency Measurement . . . . . . . . . . . . . . . . . . . . . . . . . 44
Edge-to-Edge Measurement . . . . . . . . . . . . . . . . . . . . . . 45
Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
One-Shot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Repetitive One-Shot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Chapter 3: Supported Device Driver Capabilities. . . . . . . . 51
Chapter 4: Programming Flowcharts. . . . . . . . . . . . . . . . . . 63
Single-Value Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Continuous A/D Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Continuous D/A Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Continuous Digital Input Operations . . . . . . . . . . . . . . . . . . . . . . 71
Continuous Digital Output Operations . . . . . . . . . . . . . . . . . . . . 72
Event Counting Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Up/Down Counting Operations . . . . . . . . . . . . . . . . . . . . . . . . . 75
Frequency Measurement Operations . . . . . . . . . . . . . . . . . . . . . . 77
Edge-to-Edge Measurement Operations . . . . . . . . . . . . . . . . . . . 79
Pulse Output Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Simultaneous Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Contents
Chapter 5: Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . 97
General Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Service and Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Appendix A: Specifications . . . . . . . . . . . . . . . . . . . . . . . . 103
ix
Contents
Appendix B: Connector Pin Assignments . . . . . . . . . . . . 113
Analog Input Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Digital I/O Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Analog Output, Counter/Timer, Clock, and Trigger
Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
x
About this Manual
This manual describes the features of the KUSB-3116 module, the
capabilities of the device driver, and how to program the KUSB-3116
module using DT-Open Layers™ software. Troubleshooting
information is also provided.
Intended Audience
This document is intended for engineers, scientists, technicians, or
others responsible for using and/or programming the KUSB-3116
module for data acquisition operations in the Microsoft® Windows®
2000 or Windows XP operating system. It is assumed that you have
some familiarity with data acquisition principles and that you
understand your application.
How this Manual is Organized
This manual is organized as follows:
• Chapter 1, “Overview,” describes the major features of the
KUSB-3116 module, as well as the supported software and
accessories for the modules.
• Chapter 2, “Principles of Operation,” describes all of the features
of the KUSB-3116 module and how to use them in your
application.
• Chapter 3, “Supported Device Driver Capabilities,” lists the data
acquisition subsystems and the associated features accessible
using the device driver.
• Chapter 4, “Programming Flowcharts,” describes the processes
you must follow to program the subsystems of the KUSB-3116
module using DT-Open Layers-compliant software.
xi
About this Manual
Conventions Used in this Manual
• Chapter 5, “Troubleshooting,” provides information that you can
use to resolve problems with the KUSB-3116 module and device
driver, should they occur.
• Appendix A, “Specifications,” lists the specifications of the
KUSB-3116 module.
• Appendix B, “Connector Pin Assignments,” shows the pin
assignments for the connectors on the KUSB-3116 module.
• An index completes this manual.
The following conventions are used in this manual:
• Notes provide useful information or information that requires
special emphasis, cautions provide information to help you avoid
losing data or damaging your equipment, and warnings provide
information to help you avoid catastrophic damage to yourself or
your equipment.
xii
• Items that you select or type are shown in bold.
Related Information
Refer to the following documents for more information on using the
KUSB-3116 module:
• KUSB-3116 Getting Started Manual. This manual, included on the
CD that is shipped with the module, describes the how to install
the KUSB-3116 module and related software.
• DataAcq SDK User’s Manual. For programmers who are
developing their own application programs using the Microsoft
C compiler, this manual describes how to use the DT-Open
TM
Layers
access the capabilities of your module.
DataAcq SDKTM in Windows 2000 or Windows XP to
• DTx-EZ Getting Started Manual. This manual describes how to use
the ActiveX controls provided in DTx-EZ
capabilities of your module in Microsoft Visual Basic® or Visual
C++®.
• DT-LV Link Getting Started Manual. This manual describes how to
use DT-LV Link
language to access the capabilities of your module.
• Microsoft Windows 2000 or Windows XP documentation.
• USB web site (http://www.usb.org).
Where To Get Help
Should you run into problems installing or using your KUSB-3116
module, please call the Keithley Technical Support Department.
About this Manual
TM
to access the
TM
with the LabVIEW® graphical programming
xiii
About this Manual
xiv
1
Overview
Hardware Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Supported Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1
Chapter 1
Hardware Features
The KUSB-3116 is a high-performance, multifunction data acquisition
modules for the USB (Ver. 2.0 or Ver. 1.1) bus. The key hardware
features of the KUSB-3116 module are as follows:
• Installed in a metal BNC box to provide easy connections.
• Simultaneous operation of analog input, analog output, digital
I/O, and counter/timer subsystems.
• Analog input subsystem:
− 16-bit A/D converter.
− Throughput rate up to 500 kSamples/s.
− 16 single-ended or 8 differential analog input channels.
− Programmable gain of 1, 2, 4, or 8 provides input ranges of
±10, ±5, ±2.5, and ±1.25 V.
− 1024-location channel-gain list. You can cycle through the
channel-gain list using continuous scan mode or triggered
scan mode. The maximum sampling rate when using the
channel-gain list is 500 kSamples/s.
• Analog output subsystem:
− Four 16-bit D/A converters.
− Output rate up to 500 kSamples/s.
− Output range of ±10 V.
− The DACs are deglitched to prevent noise from interfering
with the output signal.
− Output channel list. You can cycle through the output channel
list using continuous output mode or waveform mode. For
waveform generation mode, you can simultaneously update
all four DACs at 500 kS/s per channel; for continuous output
mode, you can simultaneously update all four DACs at
250 kS/s per channel.
2
• Digital I/O subsystem:
Overview
− One digital input port, consisting of 16 digital input lines. You
can program any of the first eight digital input lines to
perform interrupt-on-change operations. You can read the
value of the digital input port using the analog input
channel-gain list.
− One digital output port, consisting of 16 digital output lines.
You can output the value of the digital output port using the
output channel list.
− An additional dynamic digital output line that changes state
whenever an analog input channel is read.
• Five 32-bit counter/timer (C/T) channels that perform event
counting, up/down counting, frequency measurement,
edge-to-edge measurement, continuous pulse output, one-shot,
and repetitive one-shot operations. You can read the value of one
or more of the C/T channels using the analog input channel-gain
list.
• External or internal clock source.
• Trigger operations using a software command, an analog
threshold value, or an external digital input value as the trigger
event.
1
1
1
1
1
1
• 500 V galvanic isolation barrier that prevents ground loops to
maximize analog signal integrity and protect your computer.
1
1
1
3
Chapter 1
Supported Software
The following software is available for use with the KUSB-3116
module:
• Device Driver − This software is provided on the CD shipped
with the module. The device driver allows you to use a
KUSB-3116 module with any of the supported software packages
or utilities. Refer to the KUSB-3116 Getting Started Manual for
more information on loading and configuring the device driver.
• Quick Data Acq application − This application provides a quick
way to get a KUSB-3116 module up and running. Using the
Quick Data Acq application, you can verify the features of the
module, display data on the screen, and save data to disk.
• DataAcq SDK − This DT-Open Layers Software Develop Kit
(SDK) allows programmers to develop application programs for
the KUSB-3116 using the Microsoft C compiler in Windows 2000
or Windows XP.
• DTx-EZ − This software package contains ActiveX controls that
allow Microsoft Visual Basic® or Visual C++® programmers to
access the capabilities of the KUSB-3116 module.
• DT-LV Link − This software package allows LabVIEW®
programmers to access the capabilities of the KUSB-3116 module.
4
2
Principles of Operation
Analog Input Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Analog Output Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Digital I/O Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Counter/Timer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5
Chapter 2
Analog
Input
Channels
Figure 1 shows a block diagram of the KUSB-3116 module.
Input
MUX
Programmable
Gain (1, 2, 4, 8)
12-Bit or
16-Bit
ADC
Input
FIFO
Analog
Threshold
Trigger
Dynamic
Digital
Output
4 Analog Output Channels
ChannelGain List
(1024)
Digital I/O
16 In
16 Out
12/16-Bit
D/A
12/16-Bit
D/A
12/16-Bit
D/A
12/16-Bit
D/A
8
16
Interrupt
Logic
Output
FIFO
Input
Control
Output
Control
500 V Isolation
Barrier
USB 1.1 or 2.0 Interface
Ext. A/D
Tr ig
Ext. A/D
Clk
Ext. D/A
Tr i g
Ext. D/A
Clk
Clock
and
Trigger
Logic
5 32-Bit
Counter/
Timers
Ext. A/D Trig
Ext. A/D Clk
Ext. D/A Trig
Ext. D/A Clk
5 Clock In
5 Gate In
5 Signal Out
Figure 1: Block Diagram of the KUSB-3116 Module
6
Analog Input Features
This section describes the following features of analog input (A/D)
operations on the KUSB-3116 module:
• Input resolution, described on this page;
• Analog input channels, described on page 7;
• Input ranges and gains, described on page 14;
Principles of Operation
2
2
• Input sample clock sources, described on page 16;
• Analog input conversion modes, described on page 17;
• Input triggers, described on page 22;
• Data format and transfer, described on page 23; and
• Error conditions, described on page 25.
Input Resolution
The resolution of the KUSB-3116 module is fixed at 16 bits. You
cannot specify the resolution in software.
Analog Input Channels
You can use the analog input channels in one of the following
configurations:
• Single-ended − Single-ended channels are useful when you are
measuring high-level signals, when noise is not significant, when
the source of the input is close to the module, and when all the
input signals are referred to the same common ground.
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Chapter 2
• Pseudo-Differential − Pseudo-differential channels are useful
when noise or common-mode voltage (the difference between the
ground potentials of the signal source and the ground of the
screw terminal panel or between the grounds of other signals)
exists and when the differential configuration is not suitable for
your application. This option provides less noise rejection than
the differential configuration; however, more analog input
channels are available.
• Differential − Differential channels are useful when you want to
measure low-level signals, when noise is a significant part of the
signal, or when common-mode voltage exists.
The BNC connectors on the KUSB-3116 module are configured in the
single-ended channel configuration. To access the differential signals,
you need to use the analog input connector.
Note: For pseudo-differential inputs, specify single-ended in
software; in this case, how you wire these signals determines the
configuration.
Using the Open Layers Control Panel applet, you can also select
whether to use 10 kΩ termination resistance between the low side of
each differential channel and isolated analog ground. This feature is
particularly useful with floating signal sources. Refer to the
KUSB-3116 Getting Started Manual for more information about wiring
to inputs and configuring the driver to use bias return termination
resistance.
The KUSB-3116 module can acquire data from a single analog input
channel or from a group of analog input channels. Channels are
numbered 0 to 31 for single-ended and pseudo-differential inputs,
and 0 to 15 for differential inputs.
The following subsections describe how to specify the channels.
8
Specifying a Single Analog Input Channel
Principles of Operation
The simplest way to acquire data from a single analog input channel
is to specify the channel for a single-value analog input operation
using software; refer to page 17 for more information about
single-value operations.
You can also specify a single channel using the analog input
channel-gain list, described in the next section.
Specifying One or More Analog Input Channels
You can read data from one or more analog input channels using an
analog input channel-gain list. You can group the channels in the list
sequentially (starting either with 0 or with any other analog input
channel) or randomly. You can also specify a single channel or the
same channel more than once in the list.
Using software, specify the channels in the order you want to sample
them. You can enter up to 1,024 entries in the channel-gain list. The
channels are read in order (using continuously paced scan mode or
triggered scan mode) from the first entry in the list to the last entry in
the list. Refer to page 17 for more information about the supported
conversion modes.
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2
You can also use software to set up a channel-inhibit list. This feature
is useful if you want to discard acquired values from specific entries
in the channel-gain list. Using the channel-inhibit list, you can enable
or disable inhibition for each entry in the channel-gain list. If enabled,
the value is discarded after the channel is read; if disabled, the value
is not discarded after the channel is read.
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Chapter 2
Notes: If you select an analog input channel as the analog threshold
trigger source, the channel used for this trigger source must be the
first channel specified in the channel-gain list; refer to page 22 for
more information about this trigger source.
The maximum rate at which the module can read the analog input
channels depends on the total number of analog input channels
and/or counter/timer channels (see page 11) in the list, and whether
or not you are reading the digital input port (see the next section).
For example, since the maximum throughput of the analog input
subsystem is 500 kSamples/s, the module can read two analog input
channels at a rate of 250 kSamples/s each or four analog input
channels at a rate of 125 kSamples/s each.
Specifying the Digital Input Port in the Analog Input Channel-Gain List
The KUSB-3116 module allows you to read the digital input port (all
16 digital input lines) using the analog input channel-gain list. This
feature is particularly useful when you want to correlate the timing of
analog and digital events.
10
To read the digital input port, specify channel 16 or channel 32 in the
analog input channel-gain list. Use channel 16 for modules with 16
single-ended channels or eight differential channels; use channel 32
for modules with 32 single-ended channels or 16 differential
channels. You can enter channel 16 or 32 anywhere in the list, and
you can enter it more than once, if desired.
The digital input port is treated like any other channel in the analog
input channel-gain list; therefore, all the clocking, triggering, and
conversion modes supported for analog input channels are
supported for the digital input port, if you specify them this way.
Principles of Operation
Note: The maximum rate at which the module can read the digital
input port depends on the total number of analog input channels
(see page 9) and/or counter/timer channels (see the next section) in
the channel-gain list. For example, since the maximum throughput
of the analog input subsystem is 500 kSamples/s, the module can
read one analog input channel and the digital input port (two
channels/ports) at a rate of 250 kSamples/s each or three analog
input channels and the digital input port (four channels/ports) at a
rate of 125 kSamples/s each.
Specifying Counter/Timers in the Analog Input Channel-Gain List
The KUSB-3116 module allows you to read the value of one or more
of the five counter/timer channels using the analog input
channel-gain list. This feature is particularly useful when you want to
correlate the timing of analog and counter/timer events.
To read a counter/timer channel, specify the appropriate channel
number in the analog input channel-gain list (refer to Table 1 on page
12). You can enter a channel number anywhere in the list, and you
can enter it more than once, if desired.
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You need two channel-gain list entries to read one 32-bit counter
value. The first entry stores the lower 16-bit word, and the second
entry stores the upper 16-bit word. If you need only the lower 16-bit
word, you do not have to include the second entry. The entire 32-bit
count value is latched when the lower 16-bit word is stored. This
prevents the counter/timer from incrementing between samples.
Table 1 lists the channel number(s) to use for each counter/timer.
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Chapter 2
Table 1: Using Counter/Timers in Analog Input Channel-Gain List
Counter/Timer
Channel
C/T_0_LOW Lower 16 bits (0 to 15) of C/T 0 Channel 17
C/T_0_HI Upper 16 bits (16 to 31) of C/T 0 Channel 18
C/T_1_LOW Lower 16 bits (0 to 15) of C/T 1 Channel 19
C/T_1_HI Upper 16 bits (16 to 31) of C/T 1 Channel 20
C/T_2_LOW Lower 16 bits (0 to 15) of C/T 2 Channel 21
C/T_2_HI Upper 16 bits (16 to 31) of C/T 2 Channel 22
C/T_3_LOW Lower 16 bits (0 to 15) of C/T 3 Channel 23
C/T_3_HI Upper 16 bits (16 to 31) of C/T 3 Channel 24
C/T_4_LOW Lower 16 bits (0 to 15) of C/T 4 Channel 25
C/T_4_HI Upper 16 bits (16 to 31) of C/T 4 Channel 26
Description
Channel to Specify
in Channel-Gain List
The counter/timer channel is treated like any other channel in the
analog input channel-gain list; therefore, all the clocking, triggering,
and conversion modes supported for analog input channels are
supported for the counter/timers, if you specify them this way.
12
Principles of Operation
Note: The maximum rate at which the module can read the
counter/timers depends on the total number of counter/timer
channels and/or analog input channels (see page 9) in the list and
whether or not you are reading the digital input port (see page 10).
For example, since the maximum throughput of the analog input
subsystem is 500 kSamples/s, the module can read one analog input
channel and one counter/timer channel (two channels) at a rate of
250 kSamples/s each or three analog input channels and one
counter/timer channel (four channels) at a rate of 125 kSamples/s
each.
Performing Dynamic Digital Output Operations
Using software, you can enable a synchronous dynamic digital
output operation for the analog input subsystem. This feature is
particularly useful when you want to synchronize and control
external equipment.
One dynamic digital output line is accessible through hardware. This
line is set to a value of 0 on power up; a reset does not affect the value
of the dynamic digital output line. Note that this line is provided in
addition to the other 16 digital output lines; see page 35 for more
information about the digital I/O features.
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You specify the value (0 or 1) to write from the dynamic digital
output line using the analog input channel-gain list. A value of 0
indicates a low-level signal; a value of 1 indicates a high-level signal.
As each entry in the channel-gain list is read, the corresponding value
is output to the dynamic digital output line. For example, assume
that dynamic digital output operations are enabled; that the
channel-gain list contains analog input channels 0, 1, 2, and 3; and
that the channel-gain list contains the dynamic digital output values
1, 0, 0, 1. Figure 2 shows this configuration.
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Chapter 2
Analog Input Channel-Gain List
Analog Input
Channels
0
1
2
3
Dynamic Digital
Output Values
1
0
0
1
Figure 2: Example Using Dynamic Digital Outputs
As analog input channel 0 is read, a high-level signal is output to the
dynamic digital output line. As analog input channels 1 and 2 are
read, a low-level signal is output to the dynamic digital output line.
As analog input channel 3 is read, a high-level signal is output to the
dynamic digital output line.
Input Ranges and Gains
Values Output from
Dynamic Digital
Output Line
1
0
0
1
14
Table 2 lists the supported gains and effective bipolar input ranges for
each.
Table 2: Effective Input Range
Gain Input Range
1 ±10 V
2 ±5 V
4 ±2.5 V
8 ±1.25 V
Principles of Operation
Using software, specify a range of −10 V to +10 V. Note that this is the
range for the entire analog input subsystem, not the range per
channel.
For each channel, choose the gain that has the smallest effective range
that includes the signal you want to measure. For example, if the
range of your analog input signal is ±1.05 V, specify a range of −10 V
to +10 V for the module and use a gain of 8 for the channel; the
effective input range for this channel is then ±1.25 V, which provides
the best sampling accuracy for that channel.
The way you specify gain depends on how you specified the
channels, as described in the following subsections.
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Specifying the Gain for a Single Channel
The simplest way to specify gain for a single channel is to specify the
gain for a single-value analog input operation using software; refer to
page 17 for more information about single-value operations.
You can also specify the gain for a single channel using an analog
input channel-gain list, described in the next section.
Specifying the Gain for One or More Channels
You can specify the gain for one or more analog input channels using
an analog input channel-gain list. Using software, set up the
channel-gain list by specifying the gain for each entry in the list.
For example, assume the analog input channel-gain list contains three
entries: channels 5, 6, and 7 and gains 2, 4, and 1. A gain of 2 is
applied to channel 5, a gain of 4 is applied to channel 6, and a gain of
1 is applied to channel 7.
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Chapter 2
Note: For channel 16 or 32 (the digital input port) and channels 17
through 26 or channels 33 through 42 (the counter/timer channels),
specify a gain of 1.
Input Sample Clock Sources
The KUSB-3116 module allows you to use one of the following clock
sources to pace analog input operations:
• Internal A/D clock – Using software, specify the clock source as
internal and the clock frequency at which to pace the operation.
The minimum frequency supported is 0.75 Samples/s; the
maximum frequency supported is 500 kSamples/s.
According to sampling theory (Nyquist Theorem), specify a
frequency that is at least twice as fast as the input’s highest
frequency component. For example, to accurately sample a
20 kHz signal, specify a sampling frequency of at least 40 kHz.
Doing so avoids an error condition called aliasing, in which high
frequency input components erroneously appear as lower
frequencies after sampling.
16
• External A/D clock – An external A/D clock is useful when you
want to pace acquisitions at rates not available with the internal
A/D clock or when you want to pace at uneven intervals.
Connect an external A/D clock to the External ADC Clock input
signal on the KUSB-3116 module. Conversions start on the falling
edge of the external A/D clock input signal.
Using software, specify the clock source as external. The clock
frequency is always equal to the frequency of the external A/D
sample clock input signal that you connect to the module.