National Instruments NI PCI-6542 User manual

January 2005
373308E-01
GETTING STARTED GUIDE
NI Digital Waveform
Generator/Analyzer
This document explains how to install, configure, test, and set up a National
Instruments digital waveform generator/analyzer. This document applies
specifically to the following devices:
• NI PXI/PCI-6541/6542 (NI 654X)
• NI PXI/PCI-6551/6552 (NI 655X)
• NI PXI-6561/6562 (NI 656X)
For more information about features and programming, refer to the
NI Digital Waveform Generator/Analyzer Help at Start»Programs»
National Instruments»NI-HSDIO»Documentation»
NI Digital Waveform Generator/Analyzer Help.
Refer to the specifications document that ships with your device for detailed
specifications.
For free downloads of the most current versions of product documentation
and example programs, visit ni.com/instruments.
Contents
Conventions ...............................................................................................2
1. Verifying the System Components ........................................................4
Minimum System Requirements .......................................................4
Recommended System.......................................................................4
2. Unpacking ..............................................................................................5
3. Verifying the Kit Contents.....................................................................6
Documentation...................................................................................6
EMI Gasket (NI PXI-655XOnly) ......................................................6
4. Installing the Software ...........................................................................6
Choose and Install Your ADE ...........................................................6
Install NI-HSDIO...............................................................................7
(Optional) Install the NI Digital Waveform Editor ...........................7

NI Digital Waveform Generator/Analyzer Guide 2 ni.com
5. Installing the Hardware..........................................................................8
Installing a PXI Module.....................................................................8
Installing a PCI Device ......................................................................10
6. Configuring and Testing in MAX..........................................................11
Using the Test Panel to Generate and Acquire Data .........................12
7. Connecting Signals ................................................................................14
Connecting Cables and Accessories ..................................................14
Wiring for Common Measurements ..................................................16
8. Programming the Digital Waveform Generator/Analyzer.....................18
NI-HSDIO Instrument Driver ............................................................18
NI-HSDIO Examples .........................................................................18
Appendix A: Device Front Panels .............................................................18
Appendix B: Troubleshooting ...................................................................26
Technical Support Resources.....................................................................28
Conventions
The following conventions are used in this guide:
<> 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 tip, which alerts you to advisory
information.
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. When this symbol is marked on the
product, refer to the Read Me First: Safety and
Radio-Frequency Interference document that
shipped with your device for precautions to take.
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.

© National Instruments Corporation 3 NI Digital Waveform Generator/Analyzer Guide
CompactPCI CompactPCI refers to the core specification defined
by the PCI Industrial Computer Manufacturers
Group (PICMG).
italic Italic text denotes variables, emphasis, or a cross
reference. 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.
monospace bold Bold text in this font denotes the messages and
responses that the computer automatically prints to
the screen. This font also emphasizes lines of code
that are different from the other examples.
monospace italic Italic text in this font denotes text that is a
placeholder for a word or value that you must
supply.
PCI Peripheral Component Interconnect (PCI) is a
high-performance expansion bus architecture
originally developed by Intel to replace ISA
and EISA.
PXI PCI eXtensions for Instrumentation (PXI) is a
rugged, open system for modular instrumentation
based on CompactPCI, with special mechanical,
electrical, and software features.
1. Verifying the System Components
This section specifies the minimum system requirements and recommended
system for NI-HSDIO and your digital waveform generator/analyzer.
Minimum System Requirements
The minimum system requirements include the following components
and tools:
• Pentium 200 MHz or equivalent processor
• 64 MB RAM
• A PXI chassis and controller or desktop computer

NI Digital Waveform Generator/Analyzer Guide 4 ni.com
• 1/8 in. flathead screwdriver
• Number 1 Phillips screwdriver
• Microsoft Internet Explorer 5.5 or later
• Measurement & Automation Explorer (MAX) 3.1 or later
• A screen resolution of 800 × 600 with 256 colors (required for the
NI Script Editor)
• The appropriate cable for your device, as shown in the following table:
• NI EMC Filler Panel Kit, available from NI (part number 778700-01)
Recommended System
The recommended system requirements include the following components
and tools:
• Pentium III/Celeron 600 MHz or equivalent processor
• 256 MB RAM
• A PXI chassis and controller or desktop computer
• 1/8 in. flathead screwdriver
• Number 1 Phillips screwdriver
• Microsoft Internet Explorer 5.5 or later
• Measurement & Automation Explorer (MAX) 3.1 or later
• A screen resolution of 800 × 600 with 256 colors (required for the
NI Script Editor)
• The appropriate cable for your device, listed in Table 1.
• A compatible connectivity accessory for your NI digital waveform
generator/analyzer, listed in the following table:
Table 1. NI Digital Waveform Generator/Analyzer Cables
Device Cable Cable Part Number
NI 654XNI SHC68-C68-D2 188142-01
NI 655XNI SHC68-C68-D2 188142-01
NI 656XNI SHB12X-B12X 192344-01
Table 2. NI Digital Waveform Generator/Analyzer Accessories
Accessory Supported Devices
NI CB-2162 NI 654X, NI 655X
NI SMB-2163 NI 654X, NI 655X

© National Instruments Corporation 5 NI Digital Waveform Generator/Analyzer Guide
• Windows 2000/NT/XP, with all available critical updates and service
packs
• One of the following application development environments (ADEs):
– LabVIEW 7.0 or later (LabVIEW 7.1 or later is required to use the
NI-HSDIO Express VIs)
– LabVIEW Real-Time Module 7.1
– LabWindows™/CVI™6.0 or later
– Microsoft Visual C++ (MSVC) 6.0 or later
2. Unpacking
The NI digital waveform generator/analyzer ships in an antistatic package to
prevent electrostatic discharge (ESD). ESD can damage several components
on the device.
Caution Never touch the exposed pins of connectors.
To avoid ESD damage in handling the device, take the following precautions:
• Ground yourself with a grounding strap or by touching a grounded
object.
• Touch the antistatic package to a metal part of your computer chassis
before removing the device from the package.
Remove the device from the package and inspect it for loose components or
any other signs of damage. Notify NI if the device appears damaged in any
way. Do not install a damaged device in your computer or chassis.
Store the device in the antistatic package when the device is not in use.
3. Verifying the Kit Contents
Verify that the kit contains the following items:
❑DVD-sized case, which contains the following items:
– NI-HSDIO (High-Speed Digital I/O) instrument driver software
CDs, which include the NI Digital Waveform Generator/Analyzer
Help
– NI Digital Waveform Generator/Analyzer Getting Started Guide
❑NI digital waveform generator/analyzer
❑Mounting screw (PCI devices only)

NI Digital Waveform Generator/Analyzer Guide 6 ni.com
❑Other documentation included with the digital waveform
generator/analyzer and driver software. Refer to the Documentation
section for a list of the documentation you may have.
Documentation
The NI digital waveform generator/analyzer kit may also include the
following documents:
• NI digital waveform generator/analyzer specifications—This printed
document provides specifications for your device.
•Read Me First: Safety and Radio-Frequency Interference
• Maintain Forced-Air Cooling Note to Users
• Retrofitting Your PXI Module Note to Users
EMI Gasket (NI PXI-655XOnly)
The NI PXI-655Xkit also includes an EMI gasket and documentation that
describes under what conditions you should install the gasket. Refer to
step 5. Installing the Hardware for more information about the gasket.
4. Installing the Software
This section describes the software installation process for the NI digital
waveform generator/analyzer.
Choose and Install Your ADE
You can create applications for your digital waveform generator/analyzer
using LabVIEW 7.0 or later, LabWindows/CVI 6.0 or later, or Microsoft
Visual C++ 5.0 or later.
LabVIEW features interactive graphics, a state-of-the-art interface, and a
powerful graphical programming language. LabWindows/CVI is a complete
ANSI C ADE that features an interactive user interface, code generation
tools, and the LabWindows/CVI Data Acquisition and Easy I/O libraries.
Using LabVIEW or LabWindows/CVI can greatly reduce your application
development time.
If you have not already installed the ADE, follow the instructions in the
product documentation to install your ADE now.

© National Instruments Corporation 7 NI Digital Waveform Generator/Analyzer Guide
Install NI-HSDIO
NI-HSDIO features a set of operations and attributes that allow you to
programmatically configure and control the digital waveform
generator/analyzer. To install NI-HSDIO, complete the following steps:
1. Insert the first CD of the NI-HSDIO CD set. The NI-HSDIO installer
should open automatically. If not, select Start»Run, and enter
x :\setup.exe, where x is the letter of the CD drive.
2. Follow the instructions in the installation prompts. For troubleshooting
and operating system-specific instructions, refer to the Hardware
Installation Wizard at ni.com/support/install.
3. When the installer completes, a dialog box appears that asks if you want
to restart, shut down, or exit. Select Restart.
4. If you are using a system running the LabVIEW Real-Time Module,
download NI-HSDIO to the target using MAX. Refer to the
Measurement & Automation Explorer Remote Systems Help by selecting
Help»Help Topics»Remote Systems in MAX.
NI Script Editor
The NI Script Editor is included on the NI-HSDIO CD and is installed when
you install the driver. The NI Script Editor provides an intuitive interface
to help you develop linking and looping pattern generation operations.
NI Script Editor Help contains more information about the NI Script Editor.
You can access NI Script Editor Help by launching the NI Script Editor and
selecting Help»NI Script Editor Help from the toolbar.
(Optional) Install the NI Digital Waveform Editor
The NI Digital Waveform Editor (DWE) is included with the higher-memory
versions of NI digital waveform generator/analyzers and also can be
purchased separately at ni.com. The NI DWE allows you to easily import
data from popular third-party EDA programs, create your own waveforms,
edit these waveforms, and view acquired waveforms.
If you are using the NI DWE, install it after you install NI-HSDIO.
5. Installing the Hardware
To install your NI digital waveform generator/analyzer, follow the
instructions in the section that describes your hardware platform.
When installing your hardware, follow the instructions in this section to
ensure that your device can cool itself effectively. If the device temperature
rises above the optimal operating temperature range, the device disables
itself, and MAX or NI-HSDIO notifies you with an error message. For more

NI Digital Waveform Generator/Analyzer Guide 8 ni.com
information on re-enabling your device, refer to the I Received a Thermal
Shutdown Error section in Appendix B: Troubleshooting.
Installing a PXI Module
To install the module, refer to Figure 1 and complete the following steps:
Figure 1. PXI Installation
1. Power down the chassis before installing the module.
2. If the chassis has multiple fan speed settings, ensure that the fans are set
to the highest setting. Do not set the fan speed to low or turn the fan off.
3. Position the chassis so that you allow plenty of space between the chassis
fan intake and exhaust vents. Blocking the fans affects the air flow
needed for cooling. For more information, refer to the chassis
documentation.
4. If you need to use an EMI gasket to reduce high-frequency emissions,
install it now. Refer to the Retrofitting Your PXI Module Note to Users
for gasket installation instructions.
5. Remove the packaging material on the PXI connector and on the screws.
6. Ensure that the ejector handle is in the unlatched (downward) position,
as shown in Figure 1.
1 PXI Chassis
2 Ejector Handle
3 Captive Screw
4 NI PXI Device
3
2
4
NI PXI-1042
1

© National Instruments Corporation 9 NI Digital Waveform Generator/Analyzer Guide
7. Holding the module by the ejector handle, slide it into an empty slot,
ensuring that the base card (on the left when looking at the front of the
module) engages with the card guides in the chassis.
8. Slide the module completely into the chassis and latch by pulling up on
the ejector handle.
9. Tighten the captive screws at the top and bottom of the module front
panel.
10. Before operating the module, install all chassis covers and filler panels.
Missing filler panels disrupt the necessary air circulation in the chassis.
Note NI recommends that you install slot blockers between
modules to maximize air flow. NI recommends using the PXI
Chassis Slot Blocker Kit, part number 778678-01, available for
purchase at ni.com.
NI PXI modules are sensitive instruments that should be handled carefully.
Do not expose the module to temperatures or humidity beyond the rated
maximums. Keep the module free of dust by cleaning with compressed air
only. Do not clean the module with any solvents or liquids. For more
information about module cooling, refer to the guidelines in the Maintain
Forced-Air Cooling Note to Users included with your NI digital waveform
generator/analyzer.
Maintaining PXI Systems
Clean the fan filters on the chassis regularly to prevent air circulation path
blockage. Cleaning frequency depends on the amount of use and the
operating environment. For specific information about cleaning procedures,
and other recommended maintenance, refer to the module specifications and
the chassis user documentation.
Uninstalling PXI Modules
When removing PXI modules from the chassis, first power down the chassis.
Then ensure that you are grounded with a grounding strap or are touching a
grounded metal surface. To avoid ESD, do not touch the exposed pins of the
PXI connector or any exposed circuitry on the module. When not in use, PXI
modules should be stored in the original antistatic packaging to avoid
damage.
Caution During operation the metal surfaces of PXI modules may
become hot. Be careful when removing the module from the chassis
or when moving it to a different peripheral slot. When removing the
module, hold it by the ejector handle and front panel only.

NI Digital Waveform Generator/Analyzer Guide 10 ni.com
Installing a PCI Device
To install your PCI device, complete the following steps:
1. Power off and unplug the PC.
2. If the PC has multiple fan speed settings, ensure that the fans are set to
the highest setting.
3. Remove the PC cover.
4. Insert the device into an open PCI slot, as shown in Figure 2.
Figure 2. PCI Installation
NI recommends either leaving the slot adjacent to the fan side of the
device empty or using lower-profile devices in the slot adjacent to the
fan side.
5. Secure the device with the screw provided in the kit.
Caution It is important to completely screw the device into the PCI
slot, both for mechanical stability and for creating a solid ground
connection, which reduces signal noise. Some computer
manufacturers use a plastic securing lever to secure PCI devices;
such a lever is unacceptable and must be removed, or you must use
1 NI PCI Device 2PCISlot 3 Personal Computer
1
2
3

© National Instruments Corporation 11 NI Digital Waveform Generator/Analyzer Guide
a different chassis. Improperly secured devices may affect the
accuracy of device specifications.
6. Before operating the device, install all filler panels. Missing filler panels
disrupt the necessary air circulation in the PC.
7. Replace the PC cover.
8. Plug in and power on the PC.
Maintaining PCI Systems
Inspect the onboard fan on a regular basis to prevent fan and air circulation
path blockage. Cleaning frequency depends on the amount of use and the
operating environment.
6. Configuring and Testing in MAX
To configure and test the NI digital waveform generator/analyzer in MAX,
complete the following steps:
1. Launch MAX to configure and test the digital waveform
generator/analyzer. MAX should automatically detect the device you
installed.
2. Expand Devices and Interfaces.
If you are using an NI digital waveform generator/analyzer with the
LabVIEW Real-Time Module, expand Remote Systems. Find your
target IP address or name, expand it, and then expand Devices and
Interfaces.
3. Expand NI-DAQmx Devices.
4. Check that your device appears under NI-DAQmx Devices.
Note If your device does not appear under NI-DAQmx Devices,
MAX did not detect the device, so you might need to refresh MAX
by selecting File»Refresh from the MAX menu or pressing <F5>.
5. You can perform a self-test on devices listed under NI-DAQmx Devices.
The self-test ensures that the device is installed correctly and can
communicate with NI-HSDIO. To perform a self-test, complete the
following steps:
a. Right-click the device you want to test and select Self-Test, shown
in Figure 3.

NI Digital Waveform Generator/Analyzer Guide 12 ni.com
Figure 3. Configuration Tree Shortcut Menu
b. When the self-test finishes, a message window appears to indicate if
an error occurred. If an error occurred, refer to ni.com/support
for troubleshooting information.
Tip If you need to reset the device with a hard reset, you can do so
by right-clicking the device and selecting Reset Device from the
shortcut menu shown in Figure 3.
6. Record the device name assigned to the digital device. You need this
information when you program the device.
Using the Test Panel to Generate and Acquire Data
To verify your device configuration, use the device test panel in MAX to
generate and acquire simple digital data using your device by completing the
following steps:
1. Right-click the device under NI-DAQmx Devices, and select Test Panels
as shown in Figure 3.
2. Click the Generation tab.
3. Select the Dynamic tab on the side of the pane.
4. Click Select All to select all of your channels. The digital pattern now
appears in the graph.
5. Enter the frequency in the Clock Frequency control, located on the left
side of the test panel.

© National Instruments Corporation 13 NI Digital Waveform Generator/Analyzer Guide
6. Enter values for the generation and acquisition voltages in the controls
below the Clock Frequency control. You can choose from standard logic
families (NI 654X/655X) or enter High and Low values to create your
own custom levels (NI 655X).
7. Choose a fill pattern. The following figure shows the pattern control and
the first few signals in the window.
Tip When generating a Marching Ones or Marching Zeroes
waveform, it is convenient to make the waveform size a multiple of
the number of selected channels.
8. Click Play to generate the pattern shown in the graph on the selected
channels. The default generation option is Continuous, but you can
toggle this setting using the control below the graph.
The Play and Stop buttons are shown in the following figure.
Because the data channels on the NI digital waveform generator/analyzer
are bidirectional, while the data is being continuously generated on all of
the channels, as in the previous step, you can acquire the data being
generated.
Note Refer to the specifications for your device for information on
the setup and hold times and propagation delays associated with
generation and acquisition operations. At some frequencies,
generating and acquiring data on the same channels when no cable
is attached to the DIGITAL DATA & CONTROL (DDC) connector
violates these timing parameters and results in incorrectly sampled
data. For information on proper signal acquisition, refer to the
NI Digital Waveform Generator/Analyzer Help .
To acquire the pattern, complete the following steps:
1. Click the Acquisition tab.
2. Click Play. The device acquires the digital data that you generated in the
previous steps, and the data is displayed on the graph.
3. Click Close when you are finished.

NI Digital Waveform Generator/Analyzer Guide 14 ni.com
7. Connecting Signals
This section discusses what connections you can make to the device, and how
to connect signals to the device for performing dynamic acquisition and
dynamic generation. For device front panel diagrams and connector
descriptions, refer to Appendix A: Device Front Panels.
Connecting Cables and Accessories
To make connections to the NI digital waveform generator/analyzer front
panel SMB jack connectors, use a shielded 50 Ωcoaxial cable with an SMB
plug end.
Use an NI SHC68-C68-D2 cable for connections to the NI 654X/655XDDC
connector. The NI SHC68-C68-D2 is designed for single-ended, high-speed
digital signal transmission. The cable is shielded, with individual
microcoaxial 50 Ωlines for each signal. Use an SHB12X-B12X cable for
connections to the NI 656XDDC connector. This cable is designed for
differential, high-speed digital signal transmission.
Using Accessories (NI 654X/655XOnly)
NI recommends using the NI CB-2162 single-ended digital I/O accessory to
access the signals on the 68-pin DDC connector and to terminate the
DIO channels. The NI CB-2162 also provides a platform for circuit
prototyping and DUT testing. The NI CB-2162 is specifically designed for
use with single-ended NI digital waveform generator/analyzers
(NI 654X/655X). For more information about using the NI CB-2162, refer to
the NI CB-2162 User Guide.
NI also offers the NI SMB-2163 breakout box for National Instruments
single-ended digital waveform generator/analyzers. The NI SMB-2163 offers
coaxial SMB connectors for each channel on the DDC connector, providing
an easy way to connect to other devices for testing and debugging. For more
information about using the NI SMB-2163, refer to the NI SMB-2163 User
Guide.
Figures 4 and 5 show how to connect a single-ended NI digital waveform
generator/analyzer and the NI CB-2162 and NI SMB-2163, respectively,
using the NI SHC68-C68-D2 cable.

© National Instruments Corporation 15 NI Digital Waveform Generator/Analyzer Guide
Figure 4. Connecting the NI CB-2162 Accessory
Figure 5. Connecting the NI SMB-2163 Accessory
1 PXI Chassis with NI Digital Waveform
Generator/Analyzer
2 SHC68-C68-D2 Cable
3 NI CB-2162 Accessory
1 PXI Chassis with NI Digital Waveform
Generator/Analyzer
2 NI SMB-2163 Accessory
3 SHC68-C68-D2 Cable
NI PXI-6551
50 MHz Digital I/O
DIGITALDATA & CONTROL
PFI0
ACCESS ACTIVE
CLK
IN
CLK
OUT
13
2
J15
J5
J6
NI PXI-1042
2
3
NI PXI-6551
50MHz Digital I/O
DIGITALDATA& CONTROL
PFI0
ACCESS ACTIVE
CLK
IN
CLK
OUT
1
NI PXI-1042

NI Digital Waveform Generator/Analyzer Guide 16 ni.com
Note If you are creating your own accessory to use with your
device, you can purchase the mating connector for the VHDCI
cable from NI (part number 778914-01).
Whether you use NI cables and accessories or design your own, you should
properly terminate cables to avoid improper measurements due to signal
reflections, overshoot, and undershoot. Refer to the NI Digital Waveform
Generator/Analyzer Help for more information about signal termination.
Wiring for Common Measurements
Dynamic generation and dynamic acquisition are two categories of
applications that you can create for NI digital waveform generator/analyzers.
This section provides information on the general wiring considerations for
each type of application. Both examples use the NI CB-2162 for signal
termination.
Dynamic Generation
When performing dynamic generation, an NI digital waveform
generator/analyzer generates data through a matched impedance system that
consists of a 50 Ωoutput impedance, a 50 Ωcable, and a 50 Ωaccessory.
Figure 6 shows a diagram of such a system, using the NI 655Xas an example.
Depending on the loading of the peripheral device, you may need additional
parallel termination resistance at the destination for optimal signal quality.
Refer to the NI Digital Waveform Generator/Analyzer Help for more
information about signal termination.
Figure 6. Dynamic Generation Functional Diagram
NI 655 X
NI CB-2162
Peripheral
Device
50 Cable
50

© National Instruments Corporation 17 NI Digital Waveform Generator/Analyzer Guide
Dynamic Acquisition
When performing dynamic acquisition with the NI 654X/655X, the source
generating the signals needs a matched source impedance as close to 50 Ωas
possible to minimize signal reflections and maintain optimal signal quality.
Figure 7 shows a diagram of a dynamic acquisition system using the NI 655X
as an example.
Figure 7. Dynamic Acquisition Functional Diagram
Note NI digital waveform generator/analyzers have various input
impedance settings, as shown in the following table.
Refer to the NI Digital Waveform Generator/Analyzer Help for more
information about signal termination.
Table 3. Supported Impedance Settings
Device Supported Input Impedance
NI 654X10 kΩ
NI 655X50 Ωor 10 kΩ
NI 656X*100 Ωfor channels configured for
LVDS operation; 10 kΩfor channels
configured for single-ended operation
*NI 656Xcables use 100 Ω differential impedance rather than 50 Ωsingle-ended
impedance.
NI 655 X
NI CB-2162
RS
RTPeripheral
Device
50 Cable

NI Digital Waveform Generator/Analyzer Guide 18 ni.com
8. Programming the Digital Waveform
Generator/Analyzer
You can generate or acquire digital data with the NI digital waveform
generator/analyzer using NI-HSDIO. You also can run the NI-HSDIO
examples to demonstrate the functionality of your device.
NI-HSDIO Instrument Driver
The NI-HSDIO API features a set of operations and attributes that exercise
all the functionality of the device, including configuration, control, and other
device-specific functions.
Information about programming with NI-HSDIO is available in the
NI Digital Waveform Generator/Analyzer Help. This online document
contains hardware information, concepts, a detailed function/VI reference
for NI-HSDIO, and information specific to your device.
NI-HSDIO Examples
The NI-HSDIO examples demonstrate some of the functionality of the
NI digital waveform generator/analyzers that you can use or integrate into
your applications.
For the location of example programs that you can use as a basis for your
first NI-HSDIO program, refer to Programming»Getting Started with
NI-HSDIO in the NI Digital Waveform Generator/Analyzer Help.
Appendix A: Device Front Panels
This section contains front panel connector figures and connector description
tables that describe the signal connection options for NI digital waveform
generator/analyzers.
NI 654X/655XFront Panels and Connectors
The NI 654X/655X front panels contain four connectors—three SMB jacks
(CLK IN, PFI 0, and CLK OUT) and one 68-pin VHDCI connector
(DIGITAL DATA & CONTROL, or DDC).
Figure 8 shows the NI 6541 front panels and pinout, which are identical to
those of the NI 6542. The DDC signals are described in Table 4. The
SMB connectors are described in Table 7. The LEDs are described in
Tables 8 and 9.

© National Instruments Corporation 19 NI Digital Waveform Generator/Analyzer Guide
Figure 8. NI 654XFront Panel Connectors
NI PXI-6541
50 MHz Digital I/O
DIGITAL DATA & CONTROL
PFI 0
ACCESS ACTIVE
CLK
IN
CLK
OUT
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
DIO 31
GND
DIO 29
GND
DIO 27
GND
DIO 25
RESERVED
DIO 23
GND
DIO 21
GND
DIO 19
GND
DIO 17
GND
DIO 15
GND
DIO 13
GND
DIO 11
GND
DIO 9
GND
DIO 7
PFI 1
DIO 5
GND
DIO 3
PFI 3
DIO 1
GND
DDC CLK OUT
GND
DIO 30
GND
DIO 28
GND
DIO 26
GND
DIO 24
GND
DIO 22
GND
DIO 20
GND
DIO 18
GND
DIO 16
GND
DIO 14
RESERVED
DIO 12
GND
DIO 10
GND
DIO 8
GND
DIO 6
RESERVED
DIO 4
GND
DIO 2
PFI 2
DIO 0
GND
STROBE
GND
PFI
0
CLK
IN
CLK
OUT
NI PCI-6541
DIGITAL
DATA &
CONTROL
The Digital Data & Control connector pinout
is the same for PXI and PCI devices.

NI Digital Waveform Generator/Analyzer Guide 20 ni.com
Table 4. NI 654XDDC Connector Pins
Pins
Signal
Name
Signal
Type Signal Description
33 DDC CLK
OUT
Control Output terminal for the exported
Sample clock.
67 STROBE Control Terminal for the external Sample clock
source which can be used for pattern
acquisition.
1, 3, 5, 7, 9,
11, 13, 15, 17,
19, 21, 23, 25,
27, 29, 31, 35,
37, 39, 41, 43,
45, 47, 49, 51,
53, 55, 57, 59,
61, 63, 65
DIO <0..31> Data Bidirectional digital I/O data channels
0 through 31.
26, 30, 64 PFI <1..3> Control Input terminals to the NI 654Xfor
external triggers, or output terminals
from the NI 654Xfor events.
2, 4, 6, 10, 12,
14, 16, 18, 20,
22, 24, 28, 32,
34, 36, 38, 40,
42, 44, 46, 48,
50, 54, 56, 58,
62, 66
GND Ground Ground reference for signals.
8, 52, 60 RESERVED N/A These terminals are reserved for future
use. Do not connect to these pins.