USB-6221 16-Bit USB M Series Multifunction DAQ Device
Земля NI USB-6221 is a USB M Series multifunction data acquisition device designed for automated measurement, data logging, laboratory control and electronic validation. It combines analog input, analog output, digital I/O and counter/timer functions in an external USB enclosure.
The USB-6221 provides 16 single-ended or eight differential analog inputs with 16-bit resolution and a maximum aggregate sampling rate of 250 kS/s. It also includes two hardware-timed analog outputs, 24 individually programmable digital I/O lines and two 32-bit counters.
Screw-terminal, BNC and OEM versions support different installation requirements. The USB model requires an external 11 VDC to 30 VDC power source, unlike the smaller USB-6210 and USB-6211 bus-powered devices.
Key Features of the USB-6221
- 16 single-ended or 8 differential analog inputs
- 16-bit analog input resolution
- 250 kS/s maximum aggregate input rate
- ±0.2 V, ±1 V, ±5 V and ±10 V input ranges
- 700 kHz small-signal input bandwidth
- Two 16-bit analog outputs
- Up to 833 kS/s on one analog output
- Up to 740 kS/s per channel with two analog outputs
- 24 individually programmable digital I/O lines
- Up to eight hardware-timed digital lines
- Two 32-bit counters
- 80 MHz counter timebase
- USB 2.0 Hi-Speed interface
- External digital triggering
- NI-DAQmx driver compatibility
- Screw-terminal, BNC and OEM configurations
USB-6221 Technical Specifications
| Product Model | USB-6221 |
|---|---|
| Product Family | NI M Series multifunction DAQ |
| Analog Inputs | 16 single-ended or 8 differential |
| ADC Resolution | 16 bits |
| Maximum AI Sample Rate | 250 kS/s single-channel or aggregate |
| Input Ranges | ±0.2 V, ±1 V, ±5 V and ±10 V |
| Input Coupling | DC |
| Small-Signal Bandwidth | 700 kHz |
| Analog Outputs | 2 |
| DAC Resolution | 16 bits |
| Maximum AO Rate | 833 kS/s on one channel; 740 kS/s per channel with two channels |
| Output Range | ±10 V |
| Output Current Drive | ±5 mA |
| Цифровой ввод-вывод | 24 individually programmable lines |
| Correlated Digital I/O | 8 lines on Port 0, up to 1 MHz with an external or shared clock |
| Counters | 2 × 32-bit |
| Counter Timebases | 80 MHz, 20 MHz and 100 kHz |
| USB Interface | USB 2.0 Hi-Speed or Full-Speed |
| Power Requirement | 11 VDC to 30 VDC, 20 W external supply |
| Connector Versions | Screw terminal, BNC and OEM |
| Software Driver | НИ-DAQmx |
USB-6221 Part Number and Accessories
The USB-6221 is available in multiple mechanical and connector configurations. Confirm the complete part number because a screw-terminal USB-6221, BNC USB-6221 and OEM USB-6221 require different wiring and mounting arrangements.
| Configuration or Accessory | Описание |
|---|---|
| USB-6221 Screw Terminal | Integrated terminals for sensors, control wiring and laboratory fixtures |
| USB-6221 BNC | Direct coaxial connections for laboratory signals |
| USB-6221 OEM | Board-level configuration for integration into custom equipment |
| USB 2.0 Cable | Host-computer communication |
| 11 VDC to 30 VDC Power Supply | External power required for the enclosed USB version |
| DIN-Rail Mounting Accessory | Mounting in cabinets and industrial test systems |
16-Bit Analog Input Measurement
The USB-6221 can acquire as many as 16 ground-referenced single-ended voltage signals or eight differential signals. Differential wiring is generally preferred for low-level signals and electrically noisy environments.
The input ranges allow the ADC to be matched to different signal amplitudes. Use the smallest range that safely contains the complete signal, including expected offset and transient voltage.
Hardware-Timed Analog Output
Two 16-bit analog outputs generate programmable ±10 V signals. They can produce static voltages, periodic waveforms or nonperiodic waveforms for automated stimulus-and-response testing.
The analog outputs provide greater update speed and current drive than those on the USB-6211. Loads requiring more than ±5 mA need an external amplifier or buffer.
24 Digital I/O Lines
All 24 digital terminals can be programmed individually as inputs or outputs. The eight Port 0 lines support correlated digital acquisition or generation when supplied with a suitable sample clock.
Digital I/O is intended for logic-level signals. Use external relay, transistor or isolation hardware when controlling motors, lamps, solenoids or industrial voltage levels.
USB-6221 Applications
- Automated functional testing
- Laboratory data acquisition
- Sensor and transducer measurement
- Analog stimulus and response testing
- Digital fixture control
- Encoder and frequency measurement
- Production test systems
- Research and educational laboratories
- Portable mixed-signal measurement
Automated Test Fixtures
The USB-6221 can measure DUT voltages, generate two analog stimulus signals and control fixture logic from one device. This reduces the number of separate instruments required for basic functional testing.
Data Logging
The device can record conditioned voltage outputs from temperature, pressure, force and position sensors. Direct connection of thermocouples, strain gauges and IEPE sensors normally requires appropriate external signal conditioning.
USB-6221 Installation Workflow
Step 1: Select the Correct USB-6221 Version
Choose screw-terminal, BNC or OEM hardware according to the required installation and signal connections.
Step 2: Install NI-DAQmx
Install a compatible NI-DAQmx version before configuring the device and development software.
Step 3: Connect the External Power Supply
Use an approved 11 VDC to 30 VDC supply capable of delivering 20 W. Confirm polarity before applying power.
Step 4: Connect USB
Connect the device directly to a USB 2.0 Hi-Speed or later host port whenever possible.
Step 5: Wire the Signals
Follow the pinout for the exact connector version and select the appropriate differential, RSE or NRSE analog input mode.
Step 6: Validate the Device
Run a self-test and use NI-DAQmx test panels to verify analog input, output, digital I/O and counter operation.
USB-6221 Troubleshooting
The USB-6221 Is Not Detected
Verify both the external power supply and USB connection. Unlike USB-6210 devices, the enclosed USB-6221 requires external DC power.
Analog Input Channels Show Crosstalk
Reduce source impedance, use differential wiring and allow sufficient multiplexed-channel settling time.
The Analog Output Voltage Drops
Check whether the load exceeds the ±5 mA output-current capability. Use an external buffer for heavier loads.
Hardware-Timed Digital I/O Does Not Run
Correlated digital operation is limited to Port 0 and requires a clock from another device subsystem or an external source.
USB-6221 Comparison
| Модель | Analog Inputs | Maximum AI Rate | Analog Outputs | Цифровой ввод-вывод |
|---|---|---|---|---|
| USB-6211 | 16 | 250 kS/s | 2 at 250 kS/s | 8 static lines |
| USB-6221 | 16 | 250 kS/s | 2, up to 833 kS/s | 24 lines |
| USB-6251 | 16 | 1,25 МСм/с | 2, up to 2.86 MS/s | 24 lines |
Choose the USB-6221 for moderate-speed measurement with 24 digital lines. Choose the USB-6251 when substantially faster analog input and output performance is required.
USB-6221 Frequently Asked Questions
What is the maximum sampling rate?
The maximum analog input sampling rate is 250 kS/s aggregate.
Does the USB-6221 require external power?
Yes. The enclosed USB version requires an 11 VDC to 30 VDC, 20 W power source.
How many digital lines are available?
The USB-6221 provides 24 individually programmable digital I/O lines.
Does it support analog output?
Yes. It provides two 16-bit, ±10 V analog outputs.
Which connector versions are available?
NI documents screw-terminal, BNC and OEM USB-6221 configurations.
Recommended Related Products
- USB-6211 Multifunction DAQ Device
- USB-6251 High-Speed Multifunction DAQ
- USB-6255 80-Channel Multifunction DAQ
Request a Quote for the USB-6221
Contact us for current availability, connector configuration and project pricing for the NI USB-6221 multifunction DAQ device.
