NI-9231 Specifications

Definitions

Warranted specifications describe the performance of a model under stated operating conditions and are covered by the model warranty.

Characteristics describe values that are relevant to the use of the model under stated operating conditions but are not covered by the model warranty.

  • Typical specifications describe the performance met by a majority of models.
  • Nominal specifications describe an attribute that is based on design, conformance testing, or supplemental testing.

Specifications are Typical unless otherwise noted.

Conditions

Specifications are valid for the range -40 °C to 70 °C unless otherwise noted.

NI-9231 Pinout



Table 1. Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection

Input Characteristics

Number of channels

8 analog input channels

ADC resolution

24 bits

Type of ADC

Delta-Sigma with analog prefiltering

Sampling mode

Simultaneous

Input coupling

Software-selectable AC/DC

Type of TEDS supported

IEEE 1451.4 TEDS Class I

TEDS capacitive drive

5,000 pF

Internal master timebase (fM)

Frequency

13.1072 MHz

Accuracy

±100 ppm maximum

CompactRIO & CompactDAQ chassis data rate range (fs)
Using internal master timebase

Minimum

267 S/s

Maximum

51.2 kS/s

Using external master timebase

Minimum

244.141 S/s

Maximum

51.367 kS/s

R Series Expansion chassis data rate range (fs)
Using internal master timebase

Minimum

267 S/s

Maximum

25.6 kS/s

Using external master timebase

Minimum

244.141 S/s

Maximum

25.684 kS/s

Data rate

fs=fM4×a×b

Input delay

34/fs + 3.0 μs

Overvoltage protection

±30 V maximum on one channel at a time

Input impedance

AI+ to chassis

918 kΩ || 135 pF

AI- to chassis

50 Ω

Input voltage range

Minimum

±5 V peak

Typical

±5.1 V peak

Scaling coefficient

610,715 pV/LSB

Maximum input voltage

AI+ to Ground

±5.16 V peak

AI- to Ground

+0.7 V/-0.2 V

IEPE excitation current (software-selectable on/off)

Minimum

2 mA

Typical

2.09 mA

IEPE excitation noise

75 nArms at 51.2 kS/s

IEPE compliance voltage

19 V maximum

Note

If you are using an IEPE sensor, use the following equation to make sure your configuration meets the IEPE compliance voltage range.

(Vcommon-mode + Vbias ± Vfull-scale) must be 0 V to 19 V

where
  • Vcommon-mode is the common-mode voltage applied to the NI-9231
  • Vbias is the bias voltage of the IEPE sensor
  • Vfull-scale is the full-scale voltage of the IEPE sensor
IEPE Diagnostic Feature

Open Loop Detection

IEPE Current, <2 mA

Short Circuit Detection

AI+ to Ground, <1.2 V

High pass filter cutoff frequency (AC)

-3 dB

1.2 Hz

-0.1 dB

7.9 Hz

Figure 1. High Pass Filter Frequency Response


Table 2. Accuracy in DC Coupling
Measurement Conditions Percent of Reading (Gain Error) Percent of Range[1]1 Range equals 5 V peak (Offset Error)
Maximum (-40 °C to 70 °C) ±0.220% ±0.075%
Typical (23 °C, ±5 °C) ±0.039% ±0.016%

Offset error (AC coupling)

±0.151%, maximum

Stability of Accuracy

Gain drift

3.7 ppm/°C; 22.4 ppm/°C, maximum

Offset drift

8.6 μV/°C; 34.8 μV/°C, maximum

Passband, -0.1 dB

Frequency

0.4 * fs

Flatness (peak-to-peak), DC to 20 kHz

0.035 dB, maximum

Phase linearity

DC coupling, DC to 20 kHz

0.06°, maximum

Channel-to-channel mismatch

Gain, DC to 20 kHz

0.123 dB, maximum

Phase (fin in kHz)

f in * 0.058°, maximum

Stopband

Frequency

0.499 * fs

Rejection

105 dB

Alias free bandwidth

0.5 * fs

Alias rejection, at 2x oversample rate

f s = 51.2 kS/s

91 dB at 6.5536 MHz

f s = 267 S/s

35 dB at 546 kHz

Table 3. Idle Channel Noise
Data Rate (S/s) Decimation Rate AC or DC Coupling (μV RMS) Spectral Noise Density (nV/√Hz) at 1 kHz
51,200 64 15.5 104
34,133 32 19.4 159
25,600 128 10.9 104
12,800 256 7.8 103
6,400 512 5.6 103
3,200 1,024 4.1 103
Note The noise specifications assume the NI-9231 is using the internal master timebase frequency of 13.1072 MHz.
Table 4. Dynamic Range (At 1 kHz Input Frequency, -60 dBF amplitude, BW=0.5 * fs)
Data Rate (S/s) Decimation Rate AC or DC Coupled (dBFS)
51,200 64 107
34,133 32 105
25,600 128 110
12,800 256 113
6,400 512 116
3,200 1,024 119
Crosstalk (CH to CH)

f in 1 kHz

-116 dB

f in 10 kHz

-99 dB

CMRR, fin1 kHz

45 dB minimum

Table 5. Total Harmonic Distortion (THD) at 51.2 kS/s
Input Amplitude 1 kHz 10 kHz
-1 dBFS -103 dBc -83 dBc
-10.97 dBFS -107 dBc -88 dBc
Intermodulation distortion (IMD)[2]2 Test standards:
  • DIN 250 Hz + 8 kHz, amplitude ratio 4:1 with total amplitude at 0 dBFS
  • CCIF 14 kHz + 15 kHz, amplitude ratio 1:1 with each tone amplitude at -6 dBFS
Up to fifth order harmonic

DIN 250 Hz + 8 kHz

-89 dB

CCIF 14 kHz + 15 kHz

-79 dB

Non-harmonic SFDR[3]3 Tested with 1 kHz-60 dBFS input at 51.2 kS/s

133 dBFS

NI-9231 with 10-32 Coaxial Jack Safety Voltages

Connect only voltages that are within the following limits:

Channel-to-earth ground

±30 V maximum, Measurement Category I

Isolation

Channel-to-channel

None

Channel-to-earth ground

None

Caution Do not connect the NI-9231 to signals or use for measurements within Measurement Categories II, III, or IV.
Attention Ne connectez pas le NI-9231 à des signaux et ne l'utilisez pas pour effectuer des mesures dans les catégories de mesure II, III ou IV.
Warning Do not connect the product to signals or use for measurements within Measurement Categories II, III, or IV, or for measurements on MAINs circuits or on circuits derived from Overvoltage Category II, III, or IV which may have transient overvoltages above what the product can withstand. The product must not be connected to circuits that have a maximum voltage above the continuous working voltage, relative to earth or to other channels, or this could damage and defeat the insulation. The product can only withstand transients up to the transient overvoltage rating without breakdown or damage to the insulation. An analysis of the working voltages, loop impedances, temporary overvoltages, and transient overvoltages in the system must be conducted prior to making measurements.
Mise en garde Ne pas connecter le produit à des signaux dans les catégories de mesure II, III ou IV et ne pas l'utiliser pour des mesures dans ces catégories, ou des mesures sur secteur ou sur des circuits dérivés de surtensions de catégorie II, III ou IV pouvant présenter des surtensions transitoires supérieures à ce que le produit peut supporter. Le produit ne doit pas être raccordé à des circuits ayant une tension maximale supérieure à la tension de fonctionnement continu, par rapport à la terre ou à d'autres voies, sous peine d'endommager et de compromettre l'isolation. Le produit peut tomber en panne et son isolation risque d'être endommagée si les tensions transitoires dépassent la surtension transitoire nominale. Une analyse des tensions de fonctionnement, des impédances de boucle, des surtensions temporaires et des surtensions transitoires dans le système doit être effectuée avant de procéder à des mesures.

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.

Environmental Characteristics

Temperature

Operating

-40 °C to 70 °C

Storage

-40 °C to 85 °C

Humidity

Operating

10% RH to 90% RH, noncondensing

Storage

5% RH to 95% RH, noncondensing

Ingress protection

IP40

Pollution Degree

2

Maximum altitude

5,000 m

Shock and Vibration
Operating vibration

Random

5 g RMS, 10 Hz to 500 Hz

Sinusoidal

5 g, 10 Hz to 500 Hz

Operating shock

30 g, 11 ms half sine; 50 g, 3 ms half sine; 18 shocks at 6 orientations

To meet these shock and vibration specifications, you must panel mount the system.

Power Requirements

Power consumption from chassis

Active mode

1.00 W maximum

Sleep mode

53 μW maximum

Thermal dissipation (at 70 °C)

Active mode

1.40 W maximum

Sleep mode

0.13 W maximum

Physical Characteristics

Dimensions

Visit ni.com/dimensions and search by module number.

Weight

164 g (5.8 oz)

Calibration

You can obtain the calibration certificate and information about calibration services for the at ni.com/calibration.

Calibration Interval 2 years

1 Range equals 5 V peak

2 Test standards:

  • DIN 250 Hz + 8 kHz, amplitude ratio 4:1 with total amplitude at 0 dBFS
  • CCIF 14 kHz + 15 kHz, amplitude ratio 1:1 with each tone amplitude at -6 dBFS
Up to fifth order harmonic

3 Tested with 1 kHz-60 dBFS input at 51.2 kS/s