NI 9231 User manual
GETTING STARTED GUIDE
NI 9231
8 AI, ±5 V, 24 Bit, 51.2 kS/s/ch Simultaneous,
AC/DC Coupling, IEPE AC Coupling
This document explains how to connect to the NI 9231.
Note Before you begin, complete the software and
hardware installation procedures in your chassis
documentation.
Note The guidelines in this document are specific to
the NI 9231. The other components in the system might
not meet the same safety ratings. Refer to the
documentation for each component in the system to
determine the safety and EMC ratings for the entire
system.
Safety Guidelines
Operate the NI 9231 only as described in this document.
Caution This icon denotes a caution, which advises
you to consult documentation where this symbol is
marked.
Caution Do not operate the NI 9231 in a manner not
specified in this document. Product misuse can result in
a hazard. You can compromise the safety protection
2| ni.com | NI 9231 Getting Started Guide
built into the product if the product is damaged in any
way. If the product is damaged, return it to NI for
repair.
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
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.
NI 9231 Getting Started Guide | © National Instruments | 3
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.
Caution Do not connect the NI 9231 to signals or use
for measurements within Measurement Categories II,
III, or IV.
Safety Guidelines for Hazardous Locations
The NI 9231 is suitable for use in Class I, Division 2, Groups A,
B, C, D, T4 hazardous locations; Class I, Zone 2, AEx nA IIC T4
Gc and Ex nA IIC T4 Gc hazardous locations; and nonhazardous
locations only. Follow these guidelines if you are installing the
NI 9231 in a potentially explosive environment. Not following
these guidelines may result in serious injury or death.
Caution Do not disconnect I/O-side wires or
connectors unless power has been switched off or the
area is known to be nonhazardous.
4| ni.com | NI 9231 Getting Started Guide
Caution Do not remove modules unless power has
been switched off or the area is known to be
nonhazardous.
Caution Substitution of components may impair
suitability for Class I, Division 2, or Zone 2.
Caution The system must be installed in an enclosure
certified for the intended hazardous (classified)
location, having a tool secured cover/door, where a
minimum protection of at least IP54 is provided.
Special Conditions for Hazardous Locations Use in
Europe and Internationally
The NI 9231 has been evaluated as Ex nA IIC T4 Gc equipment
under DEMKO 12 ATEX 1202658X and is IECEx UL 14.0089X
certified. Each NI 9231 is marked II 3G and is suitable for use
in Zone 2 hazardous locations, in ambient temperatures of -40 °C
≤ Ta ≤ 70 °C. If you are using the NI 9231 in Gas Group IIC
hazardous locations, you must use the device in an NI chassis that
has been evaluated as Ex nC IIC T4, Ex IIC T4, Ex nA IIC T4, or
Ex nL IIC T4 equipment.
NI 9231 Getting Started Guide | © National Instruments | 5
Caution Transient protection shall be provided that is
set at a level not exceeding 140% of the peak rated
voltage value of 85 V at the supply terminals to the
equipment.
Caution The system shall only be used in an area of
not more than Pollution Degree 2, as defined in
IEC/EN 60664-1.
Caution The system shall be mounted in an
ATEX/IECEx-certified enclosure with a minimum
ingress protection rating of at least IP54 as defined in
IEC/EN 60079-15.
Caution The enclosure must have a door or cover
accessible only by the use of a tool.
EMC Guidelines
This product was tested and complies with the regulatory
requirements and limits for electromagnetic compatibility (EMC)
stated in the product specifications. These requirements and
limits provide reasonable protection against harmful interference
6| ni.com | NI 9231 Getting Started Guide
when the product is operated in the intended operational
electromagnetic environment.
This product is intended for use in industrial locations. However,
harmful interference may occur in some installations, when the
product is connected to a peripheral device or test object, or if the
product is used in residential or commercial areas. To minimize
interference with radio and television reception and prevent
unacceptable performance degradation, install and use this
product in strict accordance with the instructions in the product
documentation.
Furthermore, any changes or modifications to the product not
expressly approved by National Instruments could void your
authority to operate it under your local regulatory rules.
Notice To ensure the specified EMC performance,
operate this product only with shielded cables and
accessories.
Notice To ensure the specified EMC performance, the
length of all I/O cables must be no longer than 3 m
(10 ft).
NI 9231 Getting Started Guide | © National Instruments | 7
Notice Conducted RF interference on the NI 9231 can
adversely affect its I/O ports' measurement accuracy.
Preparing the Environment
Ensure that the environment in which you are using the NI 9231
meets the following specifications.
Operating temperature
(IEC 60068-2-1, IEC 60068-2-2)
-40 °C to 70 °C
Operating humidity
(IEC 60068-2-30)
10% RH to 90% RH,
noncondensing
Pollution Degree 2
Maximum altitude 5,000 m
Indoor use only.
Note Refer to the device datasheet on ni.com/manuals
for complete specifications.
8| ni.com | NI 9231 Getting Started Guide
NI 9231 Pinout
AI1+
AI1–
AI3+
AI3–
AI5+
AI5–
AI7+
AI7–
AI0+
AI0–
AI2+
AI2–
AI4+
AI4–
AI6+
AI6–
NI 9231 Getting Started Guide | © National Instruments | 9
Table 1. Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection
Grounded Connections
NI 9231
AI+
AI–
+
–
Signal
Source
Common
Mode
Voltage
10 | ni.com | NI 9231 Getting Started Guide
Floating Connections
NI 9231
AI+
AI–
+
–
Signal
Source
NI 9231 Connection Guidelines
• Make sure that devices you connect to the NI 9231 are
compatible with the module specifications.
Integrated Electronic Piezoelectric (IEPE)
Sensors
The NI 9231 provides an IEPE excitation current for each
channel to measure the IEPE sensors. Typical IEPE sensors have
a case that is electrically isolated from the IEPE electronics. As a
NI 9231 Getting Started Guide | © National Instruments | 11
result, connecting the sensor to the NI 9231 results in a floating
connection even though the case of the sensor is grounded.
Overvoltage Protection
The NI 9231 provides overvoltage protection for each channel.
Note Refer to the device datasheet on ni.com/manuals
for more information about overvoltage protection.
12 | ni.com | NI 9231 Getting Started Guide
Where to Go Next
CompactRIO CompactDAQ
RELATED INFORMATION
C Series Documentation
& Resources
ni.com/info cseriesdoc
Services
ni.com/services
NI 9231 Datasheet
NI-RIO Help
LabVIEW FPGA Help
NI 9231 Datasheet
NI-DAQmx Help
LabVIEW Help
Installs with the software
Located at ni.com/manuals
NI 9231 Getting Started Guide | © National Instruments | 13
Worldwide Support and Services
The NI website is your complete resource for technical support.
At ni.com/support, you have access to everything from
troubleshooting and application development self-help resources
to email and phone assistance from NI Application Engineers.
Visit ni.com/services for information about the services NI offers.
Visit ni.com/register to register your NI product. Product
registration facilitates technical support and ensures that you
receive important information updates from NI.
A Declaration of Conformity (DoC) is our claim of compliance
with the Council of the European Communities using the
manufacturer’s declaration of conformity. This system affords the
user protection for electromagnetic compatibility (EMC) and
product safety. You can obtain the DoC for your product by
visiting ni.com/certification. If your product supports calibration,
you can obtain the calibration certificate for your product at
ni.com/calibration.
NI corporate headquarters is located at
11500 North Mopac Expressway, Austin, Texas, 78759-3504. NI
14 | ni.com | NI 9231 Getting Started Guide
also has offices located around the world. For support in the
United States, create your service request at ni.com/support or
dial 1 866 ASK MYNI (275 6964). For support outside the
United States, visit the Worldwide Offices section of ni.com/
niglobal to access the branch office websites, which provide up-
to-date contact information.
NI 9231 Getting Started Guide | © National Instruments | 15
Information is subject to change without notice. Refer to the NI Trademarks and Logo Guidelines
at ni.com/trademarks for information on NI trademarks. Other product and company names
mentioned herein are trademarks or trade names of their respective companies. For patents
covering NI products/technology, refer to the appropriate location: Help»Patents in your software,
the patents.txt file on your media, or the National Instruments Patent Notice at ni.com/
patents. You can find information about end-user license agreements (EULAs) and third-party
legal notices in the readme file for your NI product. Refer to the Export Compliance Information at
ni.com/legal/export-compliance for the NI global trade compliance policy and how to obtain
relevant HTS codes, ECCNs, and other import/export data. NI MAKES NO EXPRESS OR
IMPLIED WARRANTIES AS TO THE ACCURACY OF THE INFORMATION CONTAINED
HEREIN AND SHALL NOT BE LIABLE FOR ANY ERRORS. U.S. Government Customers: The
data contained in 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.
© 2018 National Instruments. All rights reserved.
378041A-01 April 3, 2018
Table of contents
Other NI Control Unit manuals
