型号: PXI-6281

产品编号: 779121-01

DEVICE SPECIFICATIONS NI 6281

M Series Data Acquisition: 18-Bit, 500 kS/s, 16 AI, 24 DIO, 2 AO

The following specifications are typical at 25 °C, unless otherwise noted. For more information about the NI 6281, refer to the M Series User Manual available at ni.com/ manuals.

Analog Input

Device off

Overvoltage protection for all analog input and sense channels

Table 1. Settling Time for Multichannel Measurements

Typical Performance Graphs

Figure 1. AI Settling Error versus Time for Different Source Impedances

Figure 2. AI Small Signal Bandwidth

Figure 3. AI CMRR

AI Absolute Accuracy

AI Absolute Accuracy (Filter On)

Note Accuracies listed are valid for up to two years from the device external calibration.

Table 2. AI Absolute Accuracy (Filter On)

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

Gain tempco                                                    17 ppm/°C

AI Absolute Accuracy (Filter Off)

Note Accuracies listed are valid for up to two years from the device external calibration.

Table 3. AI Absolute Accuracy (Filter Off)

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

Gain tempco                                                    17 ppm/°C

AI Absolute Accuracy Equation

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

GainError = ResidualAIGainError + GainTempco · (TempChangeFromLastInternalCal)

+ ReferenceTempco · (TempChangeFromLastExternalCal)

OffsetError = ResidualAIOffsetError + OffsetTempco ·

(TempChangeFromLastInternalCal) + INLError

Random Noise ⋅ 3

NoiseUncertainty =  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 of the Filter On accuracy table, the absolute accuracy at full scale is as follows:

GainError = 40 ppm + 17 ppm · 1 + 1 ppm · 10 = 67 ppm

OffsetError = 8 ppm + 11 ppm · 1 + 10 ppm = 29 ppm

NoiseUncertainty =  = 18 µV

AbsoluteAccuracy = 10 V · (GainError) + 10 V · (OffsetError) + NoiseUncertainty = 980 µV Analog Triggers

Number of triggers                                             1

APFI 0 characteristics

Output FIFO size                                               8,191 samples shared among channels used

Glitch energy at midscale transition, ±10 V range

Figure 4. AO <0,1> External Reference Bandwidth

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.

Note Accuracies listed are valid for up to two years from the device external calibration.

Table 4. AO Absolute Accuracy

Reference tempco

INL error

AO Absolute Accuracy Equation

AbsoluteAccuracy = OutputValue · (GainError) + Range · (OffsetError)

GainError = ResidualGainError + GainTempco · (TempChangeFromLastInternalCal) +

ReferenceTempco · (TempChangeFromLastExternalCal)

OffsetError = ResidualOffsetError + AOOffsetTempco ·

(TempChangeFromLastInternalCal) + INLError

Digital I/O/PFI

Waveform Characteristics (Port 0 Only)

Terminals used                                                   Port 0 (P0.<0..7>)

DO Sample Clock frequency

PFI/Port 1/Port 2 Functionality

Functionality                                                   Static digital input, static digital output, timing input, timing output

Recommended Operating Conditions

Electrical Characteristics

Digital I/O Characteristics

Figure 5. Digital I/O (P0.<0..7>): I_oh versus V_oh

Figure 6. Digital I/O (PFI <0..15>/P1/P2): I_oh versus V_oh

Figure 7. Digital I/O (P0.<0..7>): I_ol versus V_ol

Figure 8. Digital I/O (PFI <0..15>/P1/P2): I_ol versus V_ol

General-Purpose Counters/Timers

Frequency Generator

Output can be available on any output PFI or RTSI terminal.

Phase-Locked Loop (PLL)

Note PCI/PXI devices only.

Number of PLLs                                              1

External Digital Triggers

Device-to-Device Trigger Bus

PCI                                                                    RTSI <0..7>⁶

The PXI device supports one of the following features:

•         May be installed in PXI Express hybrid slots

•         Or, may be used to control SCXI in PXI/SCXI combo chassis

Table 5. PXI/SCXI Combo and PXI Express Chassis Compatibility

⁶     In other sections of this document, RTSI refers to RTSI <0..7> for the PCI devices or PXI_TRIG <0..7> for PXI devices.

⁷     If you are using an USB M Series device in full-speed mode, device performance will be lower and you will not be able to achieve maximum sample/update rates.

⁸     Operating on a full-speed bus may result in lower performance.

Power Requirements

PCI/PXI

Current draw from bus during no-load condition^[6]

Current draw from bus during AI and AO overvoltage condition⁹

Caution USB devices must be powered with an NI offered AC adapter or a National Electric Code (NEC) Class 2 DC source that meets the power requirements for the device and has appropriate safety certification marks for country of use.

Caution Exceeding the current limits may cause unpredictable behavior by the device and/or PC/chassis.

PCI, +5 V terminal                                            1 A max^[7]

USB

Physical Characteristics

Calibration

Maximum Working Voltage

Maximum working voltage refers to the signal voltage plus the common-mode voltage.

Channel-to-earth                                              11 V, Measurement Category I

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 lowvoltage sources, and electronics.

Caution Do not use for measurements within Categories II, III, or IV.

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

Environmental

Indoor use only.

Shock and Vibration (PXI Only)

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 61010-1

Note For UL and other safety certifications, refer to the product label or the Online Product Certification section.

Electromagnetic Compatibility

This product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:

•         EN 61326-1 (IEC 61326-1): Class A emissions; Basic immunity

•         EN 55011 (CISPR 11): Group 1, Class A emissions

•         EN 55022 (CISPR 22): Class A emissions

•         EN 55024 (CISPR 24): Immunity

•         AS/NZS CISPR 11: Group 1, Class A emissions

•         AS/NZS CISPR 22: Class A emissions

•         FCC 47 CFR Part 15B: Class A emissions

•         ICES-001: Class A emissions

Note In the United States (per FCC 47 CFR), Class A equipment is intended for use in commercial, light-industrial, and heavy-industrial locations. In Europe, Canada, Australia and New Zealand (per CISPR 11) Class A equipment is intended for use only in heavy-industrial locations.

Note Group 1 equipment (per CISPR 11) is any industrial, scientific, or medical equipment that does not intentionally generate radio frequency energy for the treatment of material or inspection/analysis purposes.

Note For EMC declarations and certifications, and additional information, refer to the Online Product Certification section.

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)

Online Product Certification

Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for this product, visit ni.com/ certification, search by model number or product line, and click the appropriate link in the Certification column.

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 Minimize Our Environmental Impact 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.

Waste Electrical and Electronic Equipment (WEEE)

    EU Customers 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）

中国客户 National Instruments 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 National Instruments 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.)

Device Pinouts

Figure 10. NI USB-6281 Mass Termination Pinout

(AI 0–15)

                                                 TERMINAL 68                    TERMINAL 35

                                                 TERMINAL 34                     TERMINAL 1

Figure 11. NI USB-6281 Screw Terminal Pinout

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this manual was developed at private expense and is subject to the applicable limited rights and restricted data rights as set forth in FAR 52.227-14, DFAR 252.227-7014, and DFAR 252.227-7015.

© 2015—2016 National Instruments. All rights reserved.

375218C-01     Jun16

[1] An AO channel cannot be a reference or offset to itself.

[2] When the USB Screw Terminal device is powered on, the analog output signal is not defined until after the USB configuration is complete.

[3] For all USB Screw Terminal devices, when powered on, the analog output signal is not defined until after USB configuration is complete.

[4] Stresses beyond those listed under Input voltage protection may cause permanent damage to the device.

[5] The digital subsystem does not have its own dedicated internal timing engine. Therefore, a sample clock must be provided from another subsystem on the device or an external source.

[6] Does not include P0/PFI/P1/P2 and +5 V terminals.

[7] Older revisions have a self-resetting fuse that opens when current exceeds this specification. Newer revisions have a traditional fuse that opens when current exceeds this specification. This fuse is not customer-replaceable; if the fuse permanently opens, return the device to NI for repair.

[8] Has a user-replaceable socketed fuse that opens when current exceeds this specification. Refer to the M Series for information about fuse replacement.