The USB-6211 is a multifunction DAQ device. It offers analogue I/O, digital input, digital output, and two 32-bit counters. The device provides an on-board amplifier designed for fast settling times at high scanning rates. It also features signal streaming technology that gives you DMA-like bidirectional high-speed streaming of data across USB. The device is ideal for test, control, and design applications including portable data logging, field monitoring, embedded OEM, in-vehicle data acquisition, and academic. The USB-6211 features a lightweight mechanical enclosure and is bus powered for easy portability. The included NI-DAQmx driver and configuration utility simplify configuration and measurements.


≤100 Ω1 kΩ2 kΩ5 kΩ10 kΩ

406080100120601001 k10 k100 kFrequency (Hz)CMRR (dB)140

AI Absolute Accuracy (Warranted)

Note Accuracies listed are valid for up to one year from the device external calibration.

Note The input/output channels of this device are not protected for electromagnetic interference due to functional reasons. As a result, this device may experience reduced measurement accuracy or other temporary performance degradation when connected cables are routed in an environment with radiated or conducted radio frequency electromagnetic interference. To ensure that this device functions within specifications in its operational electromagnetic environment and to limit radiated emissions, care should be taken in the selection, design, and installation of measurement probes and cables.

Table 1. AI Absolute Accuracy

Nominal Range Positive Full Scale (V)	Nominal Range Negative Full Scale (V)	Residual Gain Error (ppm of Reading)	Residual Offset Error (ppm of Range)	Offset Tempco (ppm of Range/°C)	Random Noise, σ (μVrms)	Absolute Accuracy at Full Scale (μV)	Sensitivity (μV)
10	-10	75	20	34	229	2,690	91.6
5	-5	85	20	36	118	1,410	47.2
1	-1	95	25	49	26	310	10.4
0.2	-0.2	135	40	116	12	88	4.8

Note Sensitivity is the smallest voltage change that can be detected. It is a function of noise.

Gain tempco	7.3 ppm/°C
Reference tempco	5 ppm/°C
INL error	76 ppm of range

AI Absolute Accuracy Equation

AbsoluteAccuracy = Reading · (GainError) + Range · (OffsetError) + NoiseUncertainty

• GainError = ResidualAIGainError + GainTempco · (TempChangeFromLastInternalCal) + ReferenceTempco · (TempChangeFromLastExternalCal)
• OffsetError = ResidualAIOffsetError + OffsetTempco · (TempChangeFromLastInternalCal) + INLError
• NoiseUncertainty =
  Random Noise ⋅  3100√

• for a coverage factor of 3 σ and averaging 100 points.

AI Absolute Accuracy Example

Absolute accuracy at full scale on the analog input channels is determined using the following assumptions:

• TempChangeFromLastExternalCal = 10 °C
• TempChangeFromLastInternalCal = 1 °C
• number_of_readings = 100
• CoverageFactor = 3 σ

For example, on the 10 V range, the absolute accuracy at full scale is as follows:

• GainError = 75 ppm + 7.3 ppm · 1 + 5 ppm · 10 = 132 ppm
• OffsetError = 20 ppm + 34 ppm · 1 + 76 ppm = 130 ppm
• NoiseUncertainty =
  229  µV⋅ 3100√

• = 68.7 µV
• AbsoluteAccuracy = 10 V · (GainError) + 10 V · (OffsetError) + NoiseUncertainty = 2,690 µV

Analog Output

Number of channels	2
DAC resolution	16 bits
DNL	±1 LSB
Monotonicity	16 bit guaranteed
Maximum update rate 1 channel 250 kS/s 2 channels 250 kS/s per channel
Timing accuracy	50 ppm of sample rate
Timing resolution	50 ns
Output range	±10 V
Output coupling	DC
Output impedance	0.2 Ω
Output current drive	±2 mA
Overdrive protection	±30 V
Overdrive current	2.4 mA
Power-on state	±20 mV
Power-on glitch	±1 V for 200 ms
Output FIFO size	8,191 samples shared among channels used
Data transfers	USB Signal Stream, programmed I/O
AO waveform modes	Non-periodic waveform, periodic waveform regeneration mode from onboard FIFO, periodic waveform regeneration from host buffer including dynamic update
Settling time, full-scale step, 15 ppm (1 LSB)	32 µs
Slew rate	5 V/µs
Glitch energy Magnitude 100 mV Duration 2.6 µs