Product Introduction
Земля NI USB-6281 is a high-accuracy M Series multifunction data acquisition (DAQ) device designed for precision measurement, automated testing, sensor acquisition, laboratory research, and electronic validation. Its USB interface provides a convenient external connection to a host computer while combining analog input, analog output, digital I/O, and counter/timer functionality in a single measurement device.
Featuring 18-bit analog input resolution, up to 625 kS/s sampling, 16 analog input channels, two high-speed analog outputs, 24 digital I/O lines, and two 32-bit counter/timers, the USB-6281 provides a versatile solution for applications requiring both high measurement accuracy and multifunction I/O capability.
Product Overview
Земля NI USB-6281 belongs to the NI M Series high-accuracy multifunction DAQ family and is optimized for applications where analog measurement precision is a key requirement.
Compared with conventional 16-bit multifunction DAQ devices, the USB-6281 provides 18-bit analog input resolution, allowing engineers to resolve smaller voltage changes and perform more precise sensor and DC signal measurements.
In addition to precision analog acquisition, the USB-6281 provides two programmable analog outputs, correlated digital I/O, counter/timer resources, and hardware triggering. This combination enables measurement, stimulus generation, digital control, timing, and automation functions to be integrated into one USB-connected platform.
Key Features
16 Analog Input Channels
The USB-6281 provides configurable analog input channels for precision voltage and sensor measurements.
- 16 single-ended analog input channels
- 8 differential analog input channels
- Precision voltage measurement
- Multi-channel sensor acquisition
- Automated data logging
Advantage: Flexible input configurations allow engineers to balance channel density, noise rejection, and grounding requirements according to the application.
18-Bit High-Resolution Analog Input
One of the primary advantages of the USB-6281 is its 18-bit analog-to-digital conversion architecture.
- 18-bit ADC resolution
- High-accuracy voltage measurement
- Low-level signal acquisition
- Precision sensor measurements
- Detailed DC characterization
Advantage: Higher resolution helps detect smaller changes in analog signals than conventional lower-resolution general-purpose DAQ devices.
Up to 625 kS/s Analog Input Sampling
The USB-6281 provides high-performance analog acquisition for precision measurement applications.
- Up to 625 kS/s maximum analog input rate
- Hardware-timed acquisition
- Waveform measurement
- Sensor signal capture
- Automated test applications
Advantage: Combines relatively high sampling performance with 18-bit measurement resolution for demanding data acquisition systems.
Multiplexed Analog Input Architecture
The USB-6281 uses a multiplexed analog input architecture in which multiple channels share the analog-to-digital conversion subsystem.
- Multi-channel scanning
- Efficient analog acquisition
- Configurable channel sequences
- High-resolution measurement
- Flexible data acquisition
Advantage: Provides multiple precision analog channels without requiring a dedicated ADC for every input.
Programmable Analog Input Ranges
The USB-6281 supports software-selectable input ranges for optimizing measurements according to signal amplitude.
- Multiple programmable input ranges
- Bipolar voltage measurement
- Low-level signal optimization
- Sensor signal acquisition
- Software-controlled configuration
Advantage: Selecting a smaller input range for low-level signals can improve effective measurement sensitivity.
2 Analog Output Channels
The USB-6281 includes two programmable analog output channels for stimulus generation and control applications.
- 2 analog output channels
- 16-bit output resolution
- Programmable voltage generation
- Hardware-timed waveform generation
- Stimulus-and-response testing
Advantage: Allows analog stimulus generation and precision measurement to be performed using the same multifunction DAQ device.
Up to 2.86 MS/s Analog Output Update Rate
The analog output subsystem provides high-speed waveform generation capability for automated testing and experimental applications.
- Up to 2.86 MS/s analog output update rate
- Buffered waveform generation
- Dynamic voltage stimulus
- Automated test sequences
- Signal generation applications
Advantage: Supports applications requiring substantially faster analog waveform generation than simple static voltage output.
24 Digital I/O Lines
The USB-6281 provides 24 digital I/O lines for interfacing with external devices and test fixtures.
- 24 digital I/O lines
- Digital input monitoring
- Digital output control
- Correlated digital I/O
- Test fixture interfacing
Advantage: Digital control and monitoring functions can be integrated alongside precision analog measurements.
Two 32-Bit Counter/Timers
The USB-6281 includes two 32-bit counter/timer resources for hardware-timed digital measurements and generation.
- Подсчет событий
- Frequency measurement
- Period measurement
- Pulse-width measurement
- Генерация импульсов
- Encoder measurements
Advantage: Expands the DAQ system beyond analog measurement to include precise timing and event-based applications.
Analog and Digital Triggering
The USB-6281 provides hardware triggering resources for repeatable and synchronized measurement operations.
- Analog triggering
- Digital triggering
- Hardware-timed acquisition
- Triggered waveform generation
- Automated measurement sequencing
Advantage: Hardware triggering allows acquisitions and outputs to begin in response to defined signal or digital events.
USB Connectivity
The USB architecture allows the USB-6281 to connect externally to compatible computers without installing an internal PCI or PXI card.
- USB host connectivity
- External DAQ architecture
- Desktop and laboratory deployment
- Portable measurement systems
- Easy PC integration
Advantage: Provides high-accuracy multifunction data acquisition without requiring an internal expansion slot or PXI chassis.
NI-DAQmx Software Support
The USB-6281 is supported by NI-DAQmx for hardware configuration, acquisition, generation, triggering, timing, and application development.
- NI-DAQmx driver support
- Интеграция LabVIEW
- NI MAX configuration
- TestStand integration
- C/C++ and .NET development
Advantage: Provides an established software ecosystem for building custom automated test and measurement applications.
Technical Specifications
| Параметр | Описание |
|---|---|
| Product Type | USB M Series High-Accuracy Multifunction DAQ Device |
| Analog Input Channels | 16 Single-Ended / 8 Differential |
| Analog Input Resolution | 18-bit |
| Maximum Analog Input Sample Rate | Up to 625 kS/s |
| Analog Input Architecture | Multiplexed |
| Analog Output Channels | 2 |
| Analog Output Resolution | 16-битный |
| Maximum Analog Output Update Rate | Up to 2.86 MS/s |
| Цифровой ввод-вывод | 24 Lines |
| Counter/Timers | 2, 32-bit |
| Запуск | Analog and Digital Triggering |
| Host Interface | USB |
| Product Family | NI M Series Multifunction DAQ |
| Driver | НИ-DAQmx |
| Primary Applications | Precision DAQ, Automated Test, Sensor Measurement and Laboratory Research |
Software Ecosystem
The NI USB-6281 integrates with NI software platforms for precision measurement, signal generation, digital control, data logging, and automated test development.
- NI-DAQmx: Provides configuration and programming APIs for analog input, analog output, digital I/O, counters, timing, and triggering.
- LabVIEW: Enables graphical development of data acquisition, signal generation, visualization, analysis, and automated measurement applications.
- NI MAX: Provides hardware identification, configuration, self-test, diagnostics, and basic measurement testing.
- TestStand: Allows USB-6281 measurements and control functions to be incorporated into automated validation and production test sequences.
- C/C++ and .NET: Enable engineers to create custom data acquisition applications using compatible NI-DAQmx APIs.
Industries
- Automated Test
- Electronic Manufacturing
- Research and Development
- Industrial Measurement
- Automotive Testing
- Аэрокосмическая и оборонная промышленность
- Scientific Laboratories
- Electromechanical Testing
Applications
Precision Voltage Measurement
The 18-bit analog input architecture makes the USB-6281 particularly suitable for applications requiring accurate voltage measurements.
- Precision DC voltage measurement
- Low-level signal acquisition
- Electronic characterization
- Laboratory measurements
Sensor Data Acquisition
When combined with compatible sensors and signal conditioning, the USB-6281 can acquire a wide range of physical measurements.
- Pressure measurement
- Force and load measurement
- Position measurement
- General-purpose transducer acquisition
- Multi-sensor data logging
Automated Electronic Testing
The multifunction architecture can perform measurement, stimulus, digital control, and timing operations during automated test sequences.
- Functional testing
- Electronic subsystem validation
- Production testing
- Device characterization
Stimulus and Response Testing
The two analog outputs can generate programmable stimulus signals while the analog input subsystem measures the resulting DUT response.
- Voltage stimulus generation
- Device response acquisition
- Component characterization
- Automated functional testing
Laboratory Automation
USB connectivity and multifunction I/O make the USB-6281 suitable for desktop and laboratory automation systems.
- Automated experiments
- Регистрация данных
- Instrument control integration
- Prototype testing
- Research measurements
Industrial Monitoring
The USB-6281 can monitor conditioned signals from industrial equipment and automated machinery.
- Process signal monitoring
- Диагностика оборудования
- Machine measurements
- Automated inspection systems
Counter and Frequency Measurement
The two integrated counters provide hardware-based timing functionality for digital signals.
- Frequency measurement
- Подсчет событий
- Period measurement
- Pulse-width measurement
- Encoder acquisition
Comparison with Similar Multifunction DAQ Devices
| Модель | Основное различие | Best Application |
|---|---|---|
| NI USB-6281 | USB high-accuracy multifunction DAQ with 18-bit analog input, up to 625 kS/s acquisition, two analog outputs, digital I/O, and counters. | Precision USB data acquisition |
| NI PXI-6280 | PXI high-accuracy M Series DAQ designed for precision analog measurements in modular PXI systems. | Precision PXI automated test systems |
| NI PCIe-6351 | PCI Express multifunction DAQ offering higher-speed X Series architecture for desktop automated test systems. | High-performance PCI Express DAQ |
| NI PCIe-6361 | Higher-performance X Series multifunction DAQ designed for faster acquisition, generation, and advanced timing applications. | High-speed multifunction data acquisition |
Recommended Related Products
| NI PXI-6280 | 18-bit high-accuracy PXI multifunction DAQ for users building modular automated measurement systems. |
| NI PCIe-6351 | PCI Express multifunction DAQ for desktop systems requiring higher acquisition performance and advanced timing capabilities. |
| NI PCIe-6361 | High-performance X Series multifunction DAQ for faster analog, digital, timing, and automated measurement applications. |
| NI PXI-6221 | General-purpose M Series multifunction DAQ for applications where PXI integration is required but 18-bit precision is not necessary. |
Why Choose USB-6281?
- 16 analog input channels
- 18-bit high-resolution analog acquisition
- Up to 625 kS/s analog input sampling
- 2 programmable analog output channels
- Up to 2.86 MS/s analog output update rate
- 24 digital I/O lines
- Two 32-bit counter/timers
- Analog and digital triggering
- Convenient USB connectivity
- NI-DAQmx and LabVIEW support
- Suitable for precision automated measurements
- Ideal for laboratory and desktop DAQ systems
Frequently Asked Questions
What is the NI USB-6281?
The NI USB-6281 is a high-accuracy M Series multifunction USB data acquisition device that combines precision analog input, analog output, digital I/O, counter/timers, and hardware triggering.
How many analog input channels does the USB-6281 have?
The USB-6281 provides up to 16 single-ended analog input channels or 8 differential analog input channels.
What is the analog input resolution of the USB-6281?
The USB-6281 provides 18-bit analog input resolution, making it particularly suitable for precision voltage and sensor measurements.
What is the maximum analog input sample rate of the USB-6281?
The USB-6281 supports analog input sampling rates up to 625 kS/s under applicable acquisition conditions.
Does the USB-6281 use simultaneous sampling?
No. The USB-6281 uses a multiplexed analog input architecture. Multiple analog channels share the analog-to-digital conversion subsystem and are sampled sequentially rather than simultaneously.
Does the USB-6281 have analog outputs?
Yes. The USB-6281 provides two 16-bit analog output channels for programmable voltage generation, waveform generation, stimulus, and control applications.
What is the maximum analog output update rate?
The USB-6281 analog output subsystem supports update rates up to approximately 2.86 MS/s, providing high-speed waveform generation capability for compatible applications.
How many digital I/O lines does the USB-6281 have?
The USB-6281 provides 24 digital I/O lines that can be used for device monitoring, fixture control, digital communication, and correlated digital I/O applications.
Does the USB-6281 include counter/timers?
Yes. The USB-6281 provides two 32-bit counter/timers for frequency measurement, event counting, period measurement, pulse generation, encoder measurements, and other hardware-timed digital applications.
What is the difference between USB-6281 and PXI-6280?
Both devices belong to the NI high-accuracy M Series family and emphasize precision analog measurements. The USB-6281 connects directly to a host computer through USB and includes multifunction I/O for desktop and laboratory use, while the PXI-6280 is designed for modular PXI systems where integration with additional PXI instruments, chassis timing, and automated test infrastructure is required.
What is the advantage of 18-bit DAQ compared with 16-bit DAQ?
An 18-bit ADC provides more quantization levels than a 16-bit ADC across the same input range. This allows smaller changes in the input voltage to be represented digitally, which can be valuable in precision DC, low-level sensor, and characterization applications.
What software supports the USB-6281?
The USB-6281 is supported by NI-DAQmx and can be integrated with LabVIEW, NI MAX, TestStand, and compatible C/C++ and .NET applications.
Is the USB-6281 suitable for laboratory research?
Yes. Its USB connectivity, 18-bit analog acquisition, multifunction I/O, hardware triggering, and programmable analog outputs make the USB-6281 particularly useful for laboratory automation, research data acquisition, prototype characterization, and precision measurement applications.
Заключение
Земля NI USB-6281 high-accuracy M Series multifunction DAQ device provides a versatile solution for precision data acquisition, sensor measurement, automated electronic testing, waveform generation, and laboratory research. With 16 analog inputs, 18-bit resolution, sampling rates up to 625 kS/s, two analog outputs with high-speed updates, 24 digital I/O lines, two 32-bit counter/timers, hardware triggering, USB connectivity, and NI-DAQmx integration, the USB-6281 is well suited for demanding desktop and laboratory measurement systems.
