USB Data Acquisition Frequently Asked Questions (FAQ)

The following are the most frequently asked questions about NI USB data acquisition (DAQ) devices.

1. Why should I choose USB for my data acquisition?
2. On which operating systems can my data acquisition device run?
3. What performance level can USB data acquisition devices offer?
4. For which applications are USB DAQ devices most useful?
5. How far away from my computer can I place my USB DAQ device?
6. Are NI USB data acquisition devices compatible with USB 1.1 or USB 2.0?
7. Can USB data acquisition products be used in industrial environments?
8. Which certifications are provided with the USB data acquisition devices?
9. Is there a way to prevent the USB cable from disconnecting from my laptop?
10. Can I use smart TEDS sensors with NI USB data acquisition devices?
11. What is the NI ready-to-run data-logging software and how do I use it?
12. Do I need to buy a separate terminal block and cable to use my NI USB data acquisition device?
13. Do any NI USB data acquisition devices have isolation?
14. Additional Resources

Why should I choose USB for my data acquisition?

USB data acquisition devices take advantage of the plug-and-play capabilities of USB, making their installation as simple as connecting a USB memory stick to your computer.

With the combination of USB 2.0 and NI Signal Streaming, USB data acquisition devices are able to sustain high-speed, bidirectional data transfers of analog, digital, and counter I/O. 

You can use USB data acquisition devices with desktops, laptops, touch panel computers, and Windows tablet computers, but plug-in buses such as PCI Express are limited to desktops.

On which operating systems can my data acquisition device run?

National Instruments data acquisition products are compatible with most common operating systems, depending on the device. Visit the NI-DAQ driver support page for more information.

What performance level can USB data acquisition devices offer?

USB data acquisition technologies, such as NI Signal Streaming, help you achieve unprecedented performance over USB. Total throughput is system- and device-dependent, but select PCs can sustain up to 32 MB/s of data throughput.

• High-performance NI X Series devices for USB can stream data at up to 2 MS/s for analog input and up to 2.8 MS/s for analog output
• Simultaneous sampling USB X Series devices can acquire data from all eight analog inputs at 2 MS/s per channel on select PCs (16 MS/s or 32 MB/s)
• NI CompactDAQ delivers a modular platform with up to 256 channels and analog input throughput of more than 5 MS/s

For which applications are USB DAQ devices most useful?

USB data acquisition devices are flexible, general-purpose devices that work well in a variety of applications. Some common applications include the following:

• Portable or desktop data logging
  Recommended National Instruments hardware: USB X Series multifunction DAQ and NI CompactDAQ
• In-vehicle data acquisition/logging
  Recommended National Instruments hardware: bus-powered USB M Series multifunction DAQ and NI CompactDAQ
• Portable voltage and environmental measurements
  Recommended hardware: NI CompactDAQ, NI USB-9211A, NI USB-9215A, NI USB-9211, NI USB-9215, NI USB-9201, and NI USB-9221
• Industrial digital I/O
  Recommended National Instruments hardware: NI CompactDAQ, NI USB-9421, NI USB-9472, and NI USB-9481
• Embedded OEM applications
  Recommended National Instruments hardware: NI USB DAQ for OEM
• Academic lab experiments
  Recommended National Instruments hardware: NI USB-6009, NI USB-6008, NI USB-6501, bus-powered USB M Series multifunction DAQ, and NI ELVIS for USB

How far away from my computer can I place my USB DAQ device?

The USB specification limits the distance between your computer and a device or hub to 5 m. By using the maximum of five hubs, you can achieve a distance of up to 30 m. In addition, several companies make solutions that you can use to extend USB beyond its distance limits, in some cases up to 2 km. You can find three such companies linked below.

See also Icron Technologies - USB Extension, Network Technologies Inc., Opticis.

For distances further than 5 m, NI recommends that you use Ethernet or Wi-Fi data acquisition devices.

Are NI USB data acquisition devices compatible with USB 1.1 or USB 2.0?

All NI USB data acquisition devices are compatible with USB 2.0. Three speed classifications exist in USB 2.0: low-speed (1.5 Mbit/s transfer rate), full-speed (12 Mbit/s), and Hi-Speed (480 Mbit/s). NI USB data acquisition devices use both the Hi-Speed and full-speed modes of operation. Full-speed devices compatible with USB 2.0 also work with USB 1.1 hosts without any decrease in transfer rate. However, USB 2.0 devices are limited in speed if used with a USB 1.1 host or a USB 1.1 hub.

See also USB Moves into Industrial Applications.

Can USB data acquisition products be used in industrial environments?

High data throughput; ease of use; reliable communication; and availability on industrial PCs, laptops, and industrial HMIs have made USB an attractive bus technology for industrial use. Several NI products also provide built-in isolation to protect plant assets, the data acquisition system, the host PC, and the user from hazardous voltages. They also offer panel and DIN-rail mounting options, along with strain relief, to prevent accidental disconnection of a USB cable.

See also USB Moves into Industrial Applications.

Which certifications are provided with the USB data acquisition devices?

NI products comply with the applicable international requirements for product safety, electromagnetic compatibility (EMC), hazardous locations, marine, RoHS, and quality. Refer to the NI product certification Web page for product-specific certification information.

Is there a way to prevent the USB cable from disconnecting from my laptop?

An accessory is available to prevent any accidental disconnection of the USB cable from a laptop. Refer to Strain Relief Accessory.

USB X Series devices and NI CompactDAQ include USB cables with locking thumbscrews for securing the connection of the USB cable to the DAQ device.

Can I use smart TEDS sensors with NI USB data acquisition devices?

Combine USB data acquisition and smart transducer electronic data sheet (TEDS) sensors to achieve the ultimate in simple setup: a plug-and-play data acquisition system. National Instruments has worked with more than 20 sensor vendors to create Sensors Plug&Play hardware and software to parse and interpret the data from smart TEDS sensors. There are three ways that you can combine smart TEDS sensors, Sensors Plug&Play hardware and software, and USB DAQ to create a plug-and-play data acquisition system:

1. Use an NI CompactDAQ chassis with one of the following modules: NI 9219, NI 9233, NI 9234, and NI 9237. Connect the TEDS sensor to the module and use NI-DAQmx measurement services software to interpret and apply the TEDS data.
2. Use the NI SCXI-1600 USB data acquisition and control module for SCXI along with the NI SCXI-1520 bridge sensor input module and the NI SCXI-1314T TEDS terminal block. Connect any bridge-based TEDS sensor to the terminal block and use NI-DAQmx measurement services software to interpret and apply the TEDS data.

See also Sensors Plug&Play.

What is the NI ready-to-run data-logging software and how do I use it?

Windows Users

All NI USB data acquisition devices supported by NI-DAQmx also include NI LabVIEW SignalExpress LE interactive data-logging software, as shown in Figure 1. Visit the LabVIEW SignalExpress Web page to learn more about the capabilities of this software.

Mac OS/Linux OS Users

On Mac OS and Linux OS, a subset of NI data acquisition products is supported by NI-DAQmx Base driver software. This software includes ready-to-run data-logging software to help you begin taking measurements quickly.

NI LabVIEW SignalExpress

Do I need to buy a separate terminal block and cable to use my NI USB data acquisition device?

Most NI USB data acquisition devices feature built-in signal connectivity for your convenience, including screw and BNC connectors. See device model pages for more details.

Do any NI USB data acquisition devices have isolation?

Yes, several NI C Series modules include some level of isolation: bank isolation, channel-to-earth ground isolation, or channel-to-channel isolation. In addition, there are several bus-powered multifunction USB devices that feature isolation, including the USB-6215, USB-6216, and USB-6218.

Measurement and control applications often involve environments with hazardous voltages, transient signals, common-mode voltages, and fluctuating ground potentials capable of damaging measurement systems and ruining measurement accuracy. Isolation electrically separates sensor signals from the measurement system’s low-voltage backplane and offers many benefits including projection of equipment and user, improved noise immunity, ground loop removal, and increased common-mode voltage rejection.

National Instruments products are UL- and CE-certified, and all isolated devices are rated based on rigorous tests for their respective measurement categories. NI isolated data acquisition products meet both spacing requirements and high-potential withstand tests required for proper certification.

Additional Resources

Want to learn more about the advanced capabilities of NI USB products?
Download the High-Performance USB E-Kit now.

Related Links

Products and Services: USB Data Acquisition
High-Performance USB E-Kit

156 Ratings | 3.73 out of 5

Read in  Chinese (Simplified) Chinese (Traditional) English French Italian Japanese Spanish |  Print |  PDF

Reader Comments | Submit a comment »

add high-speed reference
However, USB 2.0 devices will be limited in speed if used with a USB 1.1 host. s/b However, USB 2.0 high-speed devices will be limited in speed if used with a USB 1.1 host.
- Feb 01, 2007

M Series USB 2 boards
You discuss 3 high speed USB 2 boards but you never show them. Are these the upcomming M-series USB 2 boards and if so, when will they be out?
- Feb 17, 2006

The stop button is not the same as the abort button
While the stop button in the program looks very similar to the abort button in LabVIEW, it is not the same thing. Its use is actually built into the data logger program and follows good LabVIEW programming guidelines.
- Kristi Hobbs,National Instruments. kristi.hobbs@ni.com - Aug 01, 2005

Use of "Abort" button to stop logging is poor LabVIEW practice.
Instruction 5 for the Ready-to-Run Data Logger says, "Press [stop sign] to stop logging but not exit the program." In LabVIEW, the stop sign button is used to Abort Execution, and it is considered poor practice to employ it to normally stop a VI. Therefore. the Data Logger ought to be revised to have a boolean 'STOP' control button to encourage acquistion of good LabVIEW habits.
- Jul 04, 2005