NI USB-7855R Specifications

The following specifications are typical at 25 °C unless otherwise noted.

Analog Input

Number of channels

8

Input modes

DIFF, NRSE, RSE (software-selectable; selection applies to all channels)

Type of ADC

Successive approximation register (SAR)

Resolution

16 bits

Conversion time

1 µs

Maximum sampling rate

1 MS/s (per channel)

Input impedance

Powered on

1.25 GΩ2 pF

Powered off/overload

4.0 kΩ minimum

Input signal range

±1 V, ±2 V, ±5 V, ±10 V (software-selectable)

Input bias current

±5 nA

Input offset current

±5 nA

Input coupling

DC

Overvoltage protection

Powered on

±42 V maximum

Powered off

±35 V maximum

Table 1. AI Operating Voltage Ranges Over Temperature
Range Measurement Voltage, AI+ to AI- Maximum Working Voltage (Signal + Common Mode)
Minimum (V)[1] Typical (V) Maximum (V)
±10 V ±10.37 ±10.5 ±10.63 ±12 V of ground
±5 V ±5.18 ± 5.25 ±5.32 ±10 V of ground
±2 V ±2.07 ±2.1 ±2.13 ±8.5 V of ground
±1 V ±1.03 ±1.05 ±1.06 ±8 V of ground

AI Absolute Accuracy

Absolute accuracy at full scale numbers is valid immediately following internal calibration and assumes the device is operating within 10 °C of the last external calibration. Accuracies listed are valid for up to one year from the device external calibration.

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 = 10,000
  • CoverageFactor = 3 σ
Table 2. AI Absolute Accuracy (Calibrated)
Specifications Range
±10 V ±5 V ±2 V ±1 V
Residual Gain Error (ppm of Reading) 104.4 105.9 110.6 118.4
Gain Tempco (ppm/°C) 20 20 20 20
Reference Tempco (ppm/°C) 4 4 4 4
Residual Offset Error (ppm of Range) 16.4 16.4 16.4 16.4
Offset Tempco (ppm of Range/°C) 4.18 4.17 4.41 4.63
INL Error (ppm of range) 42.52 46.52 46.52 50.52
Random Noise, σ (µVrms) 263 156 90 74
Absolute Accuracy at Full Scale (µV) 2,283 1,170 479 252
Table 3. AI Absolute Accuracy (Uncalibrated)
Specifications Range
±10 V ±5 V ±2 V ±1 V
Residual Gain Error (ppm of Reading) 2,921 3,021 3,021 3,021
Gain Tempco (ppm/°C) 20 20 20 20
Reference Tempco (ppm/°C) 4 4 4 4
Residual Offset Error (ppm of Range) 661 671 700 631
Offset Tempco (ppm of Range/°C) 4.18 4.17 4.41 4.63
INL Error (ppm of range) 42.52 46.52 46.52 50.52
Random Noise, σ (µVrms) 263 156 90 74
Absolute Accuracy at Full Scale (µV) 36,895 19,018 7,667 3,769

Calculating Absolute Accuracy

AbsoluteAccuracy=Reading×(GainError)+Range×(OffsetError)+NoiseUncertainty
GainError=ResidualGainError+GainTempco×(TempChangeFromLastInternalCal)+ReferenceTempco×(TempChangeFromLastExternalCal)
OffsetError=ResidualOffsetError+OffsetTempco×(TempChangeFromLastInternalCal)+INL_Error
NoiseUncertainty=RandomNoise×CoverageFactornumber_of_readings

Refer to the following equation for an example of calculating absolute accuracy for a 10 V reading.

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 = 10,000
  • CoverageFactor = 3 σ
GainError=104.4ppm+20ppm×1+4ppm×10
GainError=164.4ppm
OffsetError=16.4ppm+4.18ppm1+42.52ppm
OffsetError=63.1ppm
NoiseUncertainty=263µV×310,000
NoiseUncertainty=7.89µV
AbsoluteAccuracy=10V×(GainError)+10V×(OffsetError)+NoiseUncertainty
AbsoluteAccuracy=2,283µV

DC Transfer Characteristics

INL

Refer to the AI Accuracy Table

DNL

±0.4 LSB typ, ±0.9 LSB max

No missing codes

16 bits guaranteed

CMRR, DC to 60 Hz

-100 dB

Dynamic Characteristics

Bandwidth

Small signal

1 MHz

Large signal

500 kHz

Table 4. Settling Time
Range (V) Step Size (V) Accuracy
±16 LSB ±4 LSB ±2 LSB
±10 ±20.0 1.50 µs 4.00 µs 7.00 µs
±2.0 0.50 µs 0.50 µs 1.00 µs
±0.2 0.50 µs 0.50 µs 0.50 µs
±5 ±10 1.50 µs 3.50 µs 7.50 µs
±1 0.50 µs 0.50 µs 1.00 µs
±0.1 0.50 µs 0.50 µs 0.50 µs
±2 ±4 1.00 µs 3.50 µs 8.00 µs
±0.4 0.50 µs 0.50 µs 1.00 µs
±0.04 0.50 µs 0.50 µs 0.50 µs
±1 ±2 1.00 µs 3.50 µs 12.00 µs
±0.2 0.50 µs 0.50 µs 1.50 µs
±0.02 0.50 µs 0.50 µs 0.50 µs

Crosstalk

-80 dB, DC to 100 kHz

Analog Output

Output type

Single-ended, voltage output

Number of channels

8

Resolution

16 bits

Update time

1.0 µs

Maximum update rate

1 MS/s

Type of DAC

Enhanced R-2R

Range

±10 V

Output coupling

DC

Output impedance

0.5 Ω

Current drive

±2.5 mA

Protection

Short circuit to ground

Overvoltage protection

Powered on

±15 V maximum

Powered off

±10 V maximum

Power-on state

User-configurable

Power-on glitch

-1 V for 1 µs

Table 5. AO Operating Voltage Ranges for Over Temperature
Range Measurement Voltage, AO+ to AO GND
Minimum (V)[2] Typical (V) Maximum (V)
±10 V ±10.1 ±10.16 ±10.22

AO Absolute Accuracy

Absolute accuracy at full scale numbers is valid immediately following internal calibration and assumes the device is operating within 10 °C of the last external calibration. Accuracies listed are valid for up to one year from the device external calibration.

Absolute accuracy at full scale on the analog output channels is determined using the following assumptions:
  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
Table 6. AO Absolute Accuracy (Calibrated)
Specifications ±10 V Range
Residual Gain Error (ppm of Reading) 87.3
Gain Tempco (ppm/°C) 12.6
Reference Tempco (ppm/°C) 4
Residual Offset Error (ppm of Range) 41.1
Offset Tempco (ppm of Range/°C) 7.8
INL Error (ppm of range) 61
Absolute Accuracy at Full Scale (µV) 2,498
Table 7. AO Absolute Accuracy (Uncalibrated)
Specifications ±10 V Range
Residual Gain Error (ppm of Reading) 2,968.6
Gain Tempco (ppm/°C) 12.6
Reference Tempco (ppm/°C) 4
Residual Offset Error (ppm of Range) 1,004.1
Offset Tempco (ppm of Range/°C) 7.8
INL Error (ppm of range) 61
Absolute Accuracy at Full Scale (µV) 40,941

Calculating Absolute Accuracy

AbsoluteAccuracy=OutputValue×(GainError)+Range×(OffsetError)
GainError=ResidualGainError+GainTempco×(TempChangeFromLastInternalCal)+ReferenceTempco×(TempChangeFromLastExternalCal)
OffsetError=ResidualGainError+AOOffsetTempco×(TempChangeFromLastInternalCal)+INL_Error

Refer to the following equation for an example of calculating absolute accuracy for a 10 V reading.

Absolute accuracy at full scale on the analog output channels is determined using the following assumptions:
  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
GainError=87.3ppm+12.6ppm×1+4ppm×10
GainError=139.9ppm
OffsetError=41.1ppm+7.8ppm×1+61ppm
OffsetError=109.9ppm
AbsoluteAccuracy=10V×(GainError)+10V×(OffsetError)
AbsoluteAccuracy=2,498µV

DC Transfer Characteristics

INL

Refer to the AO Accuracy Table

DNL

±0.5 LSB typical, ±1 LSB maximum

Monotonicity

16 bits, guaranteed

Dynamic Characteristics

Table 8. Settling Time
Step Size Accuracy
±16 LSB ±4 LSB ±2 LSB
±20.0 V 5.3 µs 6.5 µs 7.8 µs
±2.0 3.2 µs 3.9 µs 4.4 µs
±0.2 1.8 µs 2.8 µs 3.8 µs

Slew rate

10 V/µs

Noise

250 µVrms, DC to 1 MHz

Glitch energy at midscale transition

±10 mV for 3 µs

5V Output

Output voltage

4.75 V to 5.1 V

Output current

0.5 A maximum

Overvoltage protection

±30 V

Overcurrent protection

650 mA

Digital I/O

Table 9. Channel Frequency
Connector Number of Channels Maximum Frequency
Connector 0 32 80 MHz
Connector 1 16 10 MHz

Compatibility

LVTTL, LVCMOS

Logic family

User-selectable

Default software setting

3.3 V

Table 10. Digital Input Logic Levels
Logic Family Input Low Voltage Input High Voltage
VIL (Maximum) VIH (Minimum)
1.2 V 0.42 V 0.84 V
1.5 V 0.51 V 1.01 V
1.8 V 0.61 V 1.21 V
2.5 V 0.70 V 1.60 V
3.3 V 0.80 V 2.00 V

Maximum input

3.6 V

Table 11. Digital Output Logic Levels
Logic Family Current Output Low Voltage Output High Voltage
VOL (Maximum) VOH (Minimum)
1.2 V 100 µA 0.20 V 1.00 V
1.5 V 100 µA 0.20 V 1.25 V
1.8 V 100 µA 0.20 V 1.54 V
2.5 V 100 µA 0.20 V 2.22 V
3.3 V 100 µA, 0.20 V, 3.00 V,
4 mA 0.40 V 2.40 V
Output current

Source

4.0 mA

Sink

4.0 mA

Input leakage current

±15 µA maximum

Input impedance

50 kΩ typical, pull-down

Output impedance

50 Ω

Power-on state

Programmable, by line

Protection

±20 V, single line

Digital I/O voltage switching time

2 ms maximum

Note Refer to NI RIO Software Help for more information about switching times.

Reconfigurable FPGA

FPGA type

Kintex-7 70T

Number of flip-flops

82,000

Number of LUTs

41,000

Embedded block RAM

4,860 kbits

Number of DSP48 slices

240

Timebase

40 MHz, 80 MHz, 120 MHz, 160 MHz, or 200 MHz

Timebase accuracy, onboard clock

±100 ppm

Bus Interface

USB compatibility

USB 2.0 Hi-Speed or Full-Speed[3]

Data transfers

DMA, interrupts, programmed I/O

Number of DMA channels

3

Power Requirement

Input voltage

9 V to 30 V

Maximum power

20 W

Overvoltage protection

40 V

Caution You must use either the power supply provided in the shipping kit, or another UL Listed ITE power supply marked LPS with the NI USB-7855R.

Physical Characteristics

Note If you need to clean the device, wipe it with a dry, clean towel.

Dimensions

18.5 cm × 17.3 cm × 3.6 cm (7.3 in. × 6.8 in. × 1.4 in.)

Weight

1,000 g (35.27 oz)

I/O connectors

2 × 68-pin VHDCI

Safety Voltages

Connect only voltages that are below these limits.

Channel-to-earth

±12 V, Measurement Category I

Channel-to-channel

±24 V, Measurement Category I

Caution Do not connect the NI USB-7855R to signals or use for measurements within Measurement Categories II, III, or IV.
Attention Ne connectez pas le NI USB-7855R à des signaux et ne l'utilisez pas pour effectuer des mesures dans les catégories de mesure II, III ou IV.

Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage. MAINS is a hazardous live electrical supply system that powers equipment. This category is for measurements of voltages from specially protected secondary circuits. Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment, circuits powered by regulated low-voltage sources, and electronics.

Note Measurement Categories CAT I and CAT O are equivalent. These test and measurement circuits are for other circuits not intended for direct connection to the MAINS building installations of Measurement Categories CAT II, CAT III, or CAT IV.

Safety Compliance Standards

This product is designed to meet the requirements of the following electrical equipment safety standards for measurement, control, and laboratory use:

  • IEC 61010-1, EN 61010-1
  • UL 61010-1, CSA C22.2 No. 61010-1
Note For safety certifications, refer to the product label or the Product Certifications and Declarations section.

Electromagnetic Compatibility

CE Compliance 1378

This product meets the essential requirements of applicable European Directives, as follows:

  • 2014/35/EU; Low-Voltage Directive (safety)
  • 2014/30/EU; Electromagnetic Compatibility Directive (EMC)
  • 2011/65/EU; Restriction of Hazardous Substances (RoHS)
  • 2014/53/EU; Radio Equipment Directive (RED)
  • 2014/34/EU; Potentially Explosive Atmospheres (ATEX)

Product Certifications and Declarations

Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for NI products, visit ni.com/product-certifications, search by model number, and click the appropriate link.

Environmental

Refer to the manual for the chassis you are using for more information about meeting these specifications.

Operating temperature (IEC 60068-2-1, IEC 60068-2-2)

-40 °C to 70 °C

Storage temperature (IEC 60068-2-1, IEC 60068-2-2)

-40 °C to 85 °C

Operating humidity (IEC 60068-2-78)

10% RH to 90% RH, noncondensing

Storage humidity (IEC 60068-2-78)

5% RH to 95% RH, noncondensing

Pollution Degree

2

Maximum altitude

2,000 m

Indoor use only.

Environmental Management

NI is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers.

For additional environmental information, refer to the Engineering a Healthy Planet web page at ni.com/environment. This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.

EU and UK Customers

  • 1378 Waste Electrical and Electronic Equipment (WEEE)—At the end of the product life cycle, all NI products must be disposed of according to local laws and regulations. For more information about how to recycle NI products in your region, visit ni.com/environment/weee.
  • 电子信息产品污染控制管理办法(中国RoHS)

  • 1378 中国RoHSNI符合中国电子信息产品中限制使用某些有害物质指令(RoHS)。关于NI中国RoHS合规性信息,请登录 ni.com/environment/rohs_china。(For information about China RoHS compliance, go to ni.com/environment/rohs_china.)
  • Calibration

    Recommended warm-up time

    15 minutes

    Calibration interval

    1 year

    Onboard calibration reference

    DC level[4]

    5.000 V (±2 mV)

    Temperature coefficient

    ±4 ppm/°C maximum

    Long-term stability

    ±25 ppm/1,000 h

    Note Refer to Calibration Certifications at ni.com/calibration to generate a calibration certificate for the NI USB-7855R

    Worldwide Support and Services

    Visit ni.com/support to find support resources including documentation, downloads, and troubleshooting and application development self-help such as tutorials and examples.

    Visit ni.com/services to learn about NI service offerings such as calibration options, repair, and replacement.

    Visit ni.com/register to register your NI product. Product registration facilitates technical support and ensures that you receive important information updates from NI.

    NI corporate headquarters is located at 11500 N Mopac Expwy, Austin, TX, 78759-3504, USA.

    1 The minimum measurement voltage range is the largest voltage the NI USB-7855R is guaranteed to accurately measure.

    2 The minimum measurement voltage range is the largest voltage the NI USB-7855R is guaranteed to accurately measure.

    3 Operating on a full-speed bus will result in lower performance and you might not be able to achieve maximum sampling/update rates.

    4 Actual value stored in Flash memory