USB Data Acquisition Frequently Asked Questions (FAQ)

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

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.
• Hi-Speed USB and NI signal streaming enable USB data acquisition devices to have throughput performances similar to that of their plug-in counterparts. Refer to NI Signal Streaming: Sustaining High-Speed Data Streams on USB for more information.
• You can use USB data acquisition with desktops, laptops, and PDAs.

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-DAQmx 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 users achieve unprecedented performance over USB.

• National Instruments high-speed USB M Series devices deliver bidirectional streaming at up to 1.25 MS/s for analog input and up to 2.8 MS/s for analog output.
• NI CompactDAQ delivers a modular platform with up to 256 channels and analog input throughput of over 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: NI USB-6221, NI USB-6229, NI USB-6259, NI USB-6251, and NI CompactDAQ
• In-vehicle data acquisition/logging
  Recommended National Instruments hardware: NI USB-6259, NI USB-6251, 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-6009 OEM, NI USB-6008 OEM, NI USB-6211 OEM, NI USB-6218 OEM,NI USB-6251 OEM, NI USB-6259 OEM, and NI USB-6501 OEM
• Academic lab experiments
  Recommended National Instruments hardware: NI USB-6009, NI USB-6008, NI USB-6501, 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

Note: The NI SCXI-1600, which requires different USB communication due to the two way communication SCXI requires, might not work with all extenders.  The NI SCXI-1600 has only been tested with select USB extenders, please contact NI support for further information about options with the NI SCXI 1600.

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 Mb/s transfer rate), full-speed (12 Mb/s), and Hi-Speed (480 Mb/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 galvanic isolation to product 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.

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

Combine USB data acquisition and smart 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 DAQ system:

1. Use the NI USB-6015 DAQ device and cable it to the NI SC-2350 signal conditioning carrier for TEDS sensors. Simply connect your TEDS sensor to the appropriate SCC module inside the SC-2350 and use NI-DAQmx measurement services software to automatically interpret the TEDS data and apply it to your program.
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.
3. Use the cDAQ-9172  chassis with one of the following modules: 9219, 9233, 9234, 9237. Connect the TEDS sensor to the module 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 the NI LabVIEW SignalExpress LE interactive data-logging software, as shown in Figure 1. Please visit the LabVIEW SignalExpress Web page to learn more about the capabilities of this software.

Mac OS/Linux® Users
On Mac OS and Linux OS, the NI USB-9211, USB-9215, USB-6008, and USB-6009 are supported by NI-DAQmx Base driver software. This software includes ready-to-run data-logging software to help you begin taking measurements quickly.

 

Which software works with my USB data acquisition device? Which operating systems are supported?

Table 1 shows the software and operating systems compatible with NI USB data acquisition devices:

See Also: Support: NI-DAQmx Driver Support for Windows

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 include built-in signal connectivity for your convenience, including the USB-92xx, USB-600x, USB-621x, USB-622x, USB-625x (screw terminated), and NI CompactDAQ. Table 2 shows connectivity options for devices that do not have direct D-Sub, BNC, or screw-terminal connectivity.

Do any NI USB data acquisition devices have isolation?

Many NI USB-9xxx DAQ devices have channel-to-ground (bank) isolation:
     Withstand................................. 2,300 V_rms, 1 minute max
     Continuous................................250 V_rms, Installation Category II

Additional Ressources

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

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 1, 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 1, 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 4, 2005