National Instruments 6008 User manual

USER GUIDE AND SPECIFICATIONS
NI USB-6008/6009
This guide describes how to use the National Instruments USB-6008/6009
data acquisition (DAQ) devices and lists specifications.
Introduction
The NI USB-6008/6009 provides connection to eight analog input (AI)
channels, two analog output (AO) channels, 12 digital input/output (DIO)
channels, and a 32-bit counter with a full-speed USB interface.
Note This manual revision updates naming conventions to reflect the conventions used in
NI-DAQmx. Table 1 notes the correlation between the old and updated names.
Table 1. Digital Output Driver Type Naming Conventions
Hardware Functionality NI-DAQmx Terminology
Open-drain Open collector
Push-pull Active drive

NI USB-6008/6009 User Guide and Specifications 2 ni.com
Figure 1. NI USB-6008/6009
Figure 2. NI USB-6008/6009 Back View
Table 2. Differences Between the NI USB-6008 and NI USB-6009
Feature NI USB-6008 NI USB-6009
AI Resolution 12 bits differential,
11 bits single-ended
14 bits differential,
13 bits single-ended
Maximum AI Sample Rate,
Single Channel*
10 kS/s 48 kS/s
Maximum AI Sample Rate,
Multiple Channels (Aggregate)*
10 kS/s 48 kS/s
DIO Configuration Open collector Open collector or active drive
*System dependent.
1 USB Cable Strain Relief
NI USB-6009
8 Inputs, 14-bit, Multifunction I/O
32 Digital 17
1 Analog 16
1

©National Instruments Corporation 3 NI USB-6008/6009 User Guide and Specifications
Safety Guidelines
Caution Operate the hardware only as described in these operating instructions.
The following section contains important safety information that you must
follow when installing and using the NI USB-6008/6009.
Do not operate the NI USB-6008/6009 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, contact National Instruments for repair.
Do not substitute parts or modify the device except as described in this
document. Use the device only with the chassis, modules, 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 dry cloth. 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.
• 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 modules. Remove power from signal lines before connecting
them to or disconnecting them from the device.

NI USB-6008/6009 User Guide and Specifications 4 ni.com
Operate the device at or below the Measurement Category I1. Measurement
circuits are subjected to working voltages2and transient stresses
(overvoltage) from the circuit to which they are connected during
measurement or test. Measurement categories establish standard impulse
withstand voltage levels that commonly occur in electrical distribution
systems. The following is a description of measurement categories:
• Measurement 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.
• Measurement 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 V for U.S. or 230 V for Europe).
Examples of Measurement Category II are measurements performed
on household appliances, portable tools, and similar E Series devices.
• Measurement 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-outlets in the fixed installation, and stationary motors with
permanent connections to fixed installations.
• Measurement 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.
1 Measurement Category as defined in electrical safety standard IEC 61010-1. Measurement Category is also referred to as
Installation Category.
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.

©National Instruments Corporation 5 NI USB-6008/6009 User Guide and Specifications
Software
Software support for the NI USB-6008/6009 for Windows 2000/XP/Vista
is provided by NI-DAQmx.
The NI-DAQmx CD contains example programs that you can use to get
started programming with the NI USB-6008/6009. Refer to the NI-DAQmx
for USB Devices Getting Started Guide, that shipped with your device and
is also accessible from Start»All Programs»National Instruments»
NI-DAQ for more information.
Note For information about non-Windows operating system support, refer to
ni.com/info and enter rddqld.
LabVIEW SignalExpress for DAQ
The NI-DAQmx CD includes LabVIEW SignalExpress for DAQ which is
an interactive, measurement software tool for quickly acquiring, analyzing,
and presenting data with no programming required. The application is
available at Start»All Programs»National Instruments»NI DAQ»
LabVIEW SignalExpress.

NI USB-6008/6009 User Guide and Specifications 6 ni.com
Hardware
The following block diagram shows key functional components of the
NI USB-6008/6009.
Figure 3. Device Block Diagram
P1.<0..3>
P0.<0..7>
Digital I/O Terminal Block
AI <0..7>
AO 0
AO 1
Analog I/O Terminal Block
+2.5 V/CAL
+5 V/200 mA
8 Channel
12/14b ADC
12b DAC
12b DAC
USB Microcontroller
SPI
External
Power
Supply
Vbus
Full-Speed USB Interface
USB
PFI 0

©National Instruments Corporation 7 NI USB-6008/6009 User Guide and Specifications
Setting Up Hardware
Complete the following steps to set up the hardware:
1. Install combicon screw terminal blocks by inserting them into the
combicon jacks.
2. Figure 4 illustrates the signal labels that ship in the NI USB-6008/6009
kit. You can apply the signal labels to the screw terminal blocks for
easy signal identification.
Figure 4. NI USB-6008/6009 Signal Labels
3. Refer to Table 3 and Figures 4 and 5 for signal label orientation and
affix the provided signal labels to the screw terminal blocks. Until the
signal labels are applied, you can insert the screw terminal blocks into
either of the combicon jacks.
1 Terminal Number Labels (Use Both Together)
2 Digital I/O Label
3 Single-Ended Label (Use Either)
4 Differential Label (Use Either)
ANALOG DIGITAL
3
1
4
2

NI USB-6008/6009 User Guide and Specifications 8 ni.com
Figure 5. Signal Label Application Diagram
Note Once you label the screw terminal blocks, you must only insert them into the
matching combicon jack, as indicated by the overlay label on the NI USB-6008/6009
device.
4. Connect the wiring to the appropriate screw terminals.
1 Overlay Label with Pin Orientation Guides
2 Combicon Jack
3 Signal Labels
4 USB Cable
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©National Instruments Corporation 9 NI USB-6008/6009 User Guide and Specifications
I/O Connector
The NI USB-6008/6009 ships with one detachable screw terminal block for
analog signals and one detachable screw terminal block for digital signals.
These terminal blocks provide 16 connections that use 16 AWG to
28 AWG wire.
Table 3 lists the analog terminal assignments, and Table 4 lists the digital
terminal assignments.
Table 3. Analog Terminal Assignments
Module Terminal
Signal,
Single-Ended Mode
Signal,
Differential Mode
1GND GND
2AI 0 AI 0+
3AI 4 AI 0–
4GND GND
5AI 1 AI 1+
6AI 5 AI 1–
7GND GND
8AI 2 AI 2+
9AI 6 AI 2–
10 GND GND
11 AI 3 AI 3+
12 AI 7 AI 3–
13 GND GND
14 AO 0 AO 0
15 AO 1 AO 1
16 GND GND
12345678910111213141516

NI USB-6008/6009 User Guide and Specifications 10 ni.com
Table 4. Digital Terminal Assignments
Module Terminal Signal
17 P0.0
18 P0.1
19 P0.2
20 P0.3
21 P0.4
22 P0.5
23 P0 6
24 P0.7
25 P1.0
26 P1.1
27 P1.2
28 P1.3
29 PFI 0
30 +2.5 V
31 +5 V
32 GND
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

©National Instruments Corporation 11 NI USB-6008/6009 User Guide and Specifications
Signal Descriptions
Table 5 describes the signals available on the I/O connectors.
Table 5. Signal Descriptions
Signal Name Reference Direction Description
GND — — Ground—The reference point for the
single-ended AI measurements, bias
current return point for differential mode
measurements, AO voltages, digital
signals at the I/O connector, +5 VDC
supply, and the +2.5 VDC reference.
AI <0..7> Var i e s Input Analog Input Channels 0 to 7—For
single-ended measurements, each signal is
an analog input voltage channel. For
differential measurements, AI 0 and AI 4
are the positive and negative inputs of
differential analog input channel 0.
The following signal pairs also form
differential input channels:
<AI 1, AI 5>, <AI 2, AI 6>, and
<AI3,AI7>.
AO 0 GND Output Analog Channel 0 Output—Supplies the
voltage output of AO channel 0.
AO 1 GND Output Analog Channel 1 Output—Supplies the
voltage output of AO channel 1.
P1.<0..3>
P0.<0..7>
GND Input or
Output
Digital I/O Signals—You can
individually configure each signal as an
input or output.
+2.5 V GND Output +2.5 V External Reference—Provides a
reference for wrap-back testing.
+5 V GND Output +5 V Power Source—Provides +5V
power up to 200 mA.
PFI 0 GND Input PFI 0—This pin is configurable as either a
digital trigger or an event counter input.

NI USB-6008/6009 User Guide and Specifications 12 ni.com
LED
The NI USB-6008/6009 device has a green LED next to the USB
connector. When the device is connected to a USB port, the LED blinks
steadily to indicate that the device is initialized and is receiving power from
the connection.
If the LED is not blinking, it may mean that the device is not initialized or
the computer is in standby mode. In order for the device to be recognized,
the device must be connected to a computer that has NI-DAQmx installed
on it. If your device is not blinking, make sure your computer has the latest
version of NI-DAQmx installed on it, and the computer is not in standby
mode.
Analog Input
You can connect analog input signals to the NI USB-6008/6009 through
the I/O connector. Refer to Table 5 for more information about connecting
analog input signals.
Analog Input Circuitry
Figure 6 illustrates the analog input circuitry of the NI USB-6008/6009.
Figure 6. Analog Input Circuitry
MUX
The NI USB 6008/6009 has one analog-to-digital converter (ADC). The
multiplexer (MUX) routes one AI channel at a time to the PGA.
AI
+2.5 VREF
39.2 kΩ
127 kΩ
30.9 kΩPGA
Input Range
Selection
AI FIFO
ADC
MUX

©National Instruments Corporation 13 NI USB-6008/6009 User Guide and Specifications
PGA
The progammable-gain amplifier provides input gains of 1, 2, 4, 5, 8,
10, 16, or 20 when configured for differential measurements and gain
of 1 when configured for single-ended measurements. The PGA gain is
automatically calculated based on the voltage range selected in the
measurement application.
A/D Converter
The analog-to-digital converter (ADC) digitizes the AI signal by
converting the analog voltage into a digital code.
AI FIFO
The NI USB-6008/6009 can perform both single and multiple A/D
conversions of a fixed or infinite number of samples. A first-in-first-out
(FIFO) buffer holds data during AI acquisitions to ensure that no data
is lost.
Analog Input Modes
You can configure the AI channels on the NI USB-6008/6009 to take
single-ended or differential measurements. Refer to Table 5 for more
information about I/O connections for single-ended or differential
measurements.
Connecting Differential Voltage Signals
For differential signals, connect the positive lead of the signal to the AI+
terminal, and the negative lead to the AI– terminal.
Figure 7. Connecting a Differential Voltage Signal
AI+
Voltage
Source NI USB-6008/6009
AI–

NI USB-6008/6009 User Guide and Specifications 14 ni.com
The differential input mode can measure ±20 V signals in the ±20 V range.
However, the maximum voltage on any one pin is ±10 V with respect to
GND. For example, if AI 1 is +10 V and AI 5 is –10 V, then the
measurement returned from the device is +20 V.
Figure 8. Example of a Differential 20 V Measurement
Connecting a signal greater than ±10 V on either pin results in a clipped
output.
Figure 9. Exceeding ±10 V on AI Returns Clipped Output
–5
–10
–15
–20
20
15
10
5
0
Amplitude (V)
AI 1
AI 5
Result
–5
–10
–15
–20
20
15
10
5
0
Amplitude (V)
AI 1
AI 5
Result

©National Instruments Corporation 15 NI USB-6008/6009 User Guide and Specifications
Connecting Reference Single-Ended Voltage Signals
To connect reference single-ended voltage signals (RSE) to the
NI USB-6008/6009, connect the positive voltage signal to the desired
AI terminal, and the ground signal to a GND terminal.
When no signals are connected to the analog input terminal, the internal
resistor divider may cause the terminal to float to approximately 1.4 V
when the analog input terminal is configured as RSE. This behavior is
normal and does not affect the measurement when a signal is connected.
Figure 10. Connecting a Reference Single-Ended Voltage Signal
Digital Trigger
When an AI task is defined, you can configure PFI 0 as a digital trigger
input. When the digital trigger is enabled, the AI task waits for a rising or
falling edge on PFI 0 before starting the acquisition. To use ai/Start Trigger
with a digital source, specify PFI 0 as the source and select rising or falling
edge.
AI
Voltage
Source NI USB-6008/6009
GND

NI USB-6008/6009 User Guide and Specifications 16 ni.com
Analog Output
The NI USB-6008/6009 has two independent AO channels that can
generate outputs from 0–5 V. All updates of AO lines are software-timed.
Analog Output Circuitry
Figure 11 illustrates the analog output circuitry for the NI USB-6008/6009.
Figure 11. Analog Output Circuitry
DACs
Digital-to-analog converts (DACs) convert digital codes to analog
voltages.
Connecting Analog Output Loads
To connect loads to the NI USB-6008/6009, connect the positive lead of the
load to the AO terminal, and connect the ground of the load to a GND
terminal.
Figure 12. Connecting a Load
REF(+) REF(–)
12-Bit
DAC
Output
Buffer
50 Ω
AO
+5 V
GND
AI
Voltage
Source NI USB-6008/6009
GND

©National Instruments Corporation 17 NI USB-6008/6009 User Guide and Specifications
Minimizing Glitches on the Output Signal
When you use a DAC to generate a waveform, you may observe glitches in
the output signal. These glitches are normal; when a DAQ switches from
one voltage to another, it produces glitches due to released charges. The
largest glitches occur when the most significant bit of the DAC code
changes. You can build a lowpass deglitching filter to remove some of
these glitches, depending on the frequency and nature of the output signal.
Refer to ni.com/support for more information about minimizing
glitches.
Digital I/O
The NI USB-6008/6009 has 12 digital lines, P0.<0..7> and P1.<0..3>,
which comprise the DIO port. GND is the ground-reference signal for the
DIO port. You can individually program all lines as inputs or outputs.
Digital I/O Circuitry
Figure 13 shows P0.<0..7> connected to example signals configured as
digital inputs and digital outputs. You can configure P1.<0..3> similarly.
Figure 13. Example of Connecting a Load
1 P0.0 configured as an open collector digital output driving a LED
2 P0.2 configured as a active drive digital output driving a LED
3 P0.4 configured as a digital input receiving a TTL signal from a gated invertor
4 P0.7 configured as a digital input receiving a 0 V or 5 V signal from a switch
+5 V
LED
Switch
I/O Connector
GND
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
+5 V
LED
1
2
3
4
TTL Signal

NI USB-6008/6009 User Guide and Specifications 18 ni.com
Caution Exceeding the maximum input voltage ratings or maximum output ratings, which
are listed in the Specifications section, can damage the DAQ device and the computer.
National Instruments is not liable for any damage resulting from such signal connections.
Source/Sink Information
The default configuration of the NI USB-6008/6009 DIO ports is open
collector, allowing 5 V operation, with an onboard 4.7 kΩ pull-up resistor.
An external, user-provided, pull-up resistor can be added to increase the
source current drive up to a 8.5 mA limit per line as shown in Figure 14.
The NI USB-6009 ports can also be configured as active drive using the
DAQmx API, allowing 3.3 V operation with a source/sink current limit of
±8.5 mA. Refer to the NI-DAQmx Help for more information about how to
set the DIO configuration.
Figure 14. Example of Connecting External User-Provided Resistor
Complete the following steps to determine the value of the user-provided
pull-up resistor:
1. Place an ammeter in series with the load.
2. Place a variable resistor between the digital output line and the +5 V.
3. Adjust the variable resistor until the ammeter current reads as the
intended current. The intended current must be less than 8.5 mA.
4. Remove the ammeter and variable resistor from your circuit.
5. Measure the resistance of the variable resistor. The measured
resistance is the ideal value of the pull-up resistor.
GND
P0.0
+5 V
Rp
Re
Rl
NI USB-6008/6009
Load
A
+5 V
Port Pad
4.7 KΩOnboard Resistor
External
Pull-up
Resistor

©National Instruments Corporation 19 NI USB-6008/6009 User Guide and Specifications
6. Select a static resistor value for your pull-up resistor that is greater than
or equal to the ideal resistance.
7. Re-connect the load circuit and the pull-up resistor.
I/O Protection
To protect the NI USB-6008/6009 against overvoltage, undervoltage, and
overcurrent conditions, as well as ESD events, you should avoid these fault
conditions by using the following guidelines:
• If you configure a DIO line as an output, do not connect it to any
external signal source, ground signal, or power supply.
• If you configure a DIO line as an output, understand the current
requirements of the load connected to these signals. Do not exceed
the specified current output limits of the DAQ device.
National Instruments has several signal conditioning solutions for
digital applications requiring high current drive.
• If you configure a DIO line as an input, do not drive the line with
voltages outside of its normal operating range. The DIO lines have
a smaller operating range than the AI signals.
• Treat the DAQ device as you would treat any static sensitive device.
Always properly ground yourself and the equipment when handling
the DAQ device or connecting to it.
Power-On States
At system startup and reset, the hardware sets all DIO lines to
high-impedance inputs. The DAQ device does not drive the signal
high or low. Each line has a weak pull-up resistor connected to it.
Static DIO
Each of the NI USB-6008/6009 DIO lines can be used as a static DI or DO
line. You can use static DIO lines to monitor or control digital signals. All
samples of static DI lines and updates of DO lines are software-timed.
Event Counter
You can configure PFI 0 as a source for a gated invertor counter input edge
count task. In this mode, falling-edge events are counted using a 32-bit
counter. For more information about event timing requirements, refer to the
Specifications section.

NI USB-6008/6009 User Guide and Specifications 20 ni.com
Reference and Power Sources
The NI USB-6008/6009 creates an external reference and supplies a power
source. All voltages are relative to COM unless otherwise noted.
+2.5 External References
The NI USB-6008/6009 creates a high-purity reference voltage supply for
the ADC using a multi-state regulator, amplifier, and filter circuit. The
resulting +2.5 V reference voltage can be used as a signal for self test.
+5 V Power Source
The NI USB-6008/6009 supplies a 5 V, 200 mA output. This source can be
used to power external components.
Note While the device is in USB suspend, the output is disabled.
Specifications
The following specifications are typical at 25 °C, unless otherwise noted.
Analog Input
Converter type ........................................Successive approximation
Analog inputs..........................................8 single-ended, 4 differential,
software selectable
Input resolution
NI USB-6008...................................12 bits differential,
11 bits single-ended
NI USB-6009...................................14 bits differential,
13 bits single-ended
Max sampling rate1
NI USB-6008...................................10 kS/s
NI USB-6009...................................48 kS/s
AI FIFO ..................................................512 bytes
Timing resolution ...................................41.67 ns (24 MHz timebase)
1 System dependent.