National Instruments NI-9238 User manual

GETTING STARTED GUIDE
NI 9238
4 AI, ±500 mV, 24 Bit, 50 kS/s/ch Simultaneous

This document explains how to connect to the NI 9238.
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 9238. 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 9238 only as described in this document.
Caution Do not operate the NI 9238 in a manner not
specified in this document. Product misuse can result in
a hazard. You can compromise the safety protection
built into the product if the product is damaged in any
way. If the product is damaged, return it to NI for
repair.
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Hazardous Voltage This icon denotes a warning
advising you to take precautions to avoid electrical
shock with the NI 9238.
Safety Voltages
Connect only voltages that are within the following limits.
Channel-to-channel isolation
Up to 2,000 m altitude
Continuous 250 Vrms, Measurement
Category II
Withstand 1,500 Vrms, verified by a 5 s
dielectric test
2,001 m to 5,000 m altitude
Continuous 60 VDC, Measurement
Category I
Withstand 1,000 VDC
NI 9238 Getting Started Guide | © National Instruments | 3

Channel-to-earth ground isolation
Up to 2,000 m altitude
Continuous 250 Vrms, Measurement
Category II
Withstand 3,000 Vrms, verified by a 5 s
dielectric test
2,001 m to 5,000 m altitude
Continuous 60 VDC, Measurement
Category I
Withstand 1,000 VDC
Division 2 and Zone 2
hazardous locations
applications (Channel-to-
channel and channel-to-
earth ground)
60 VDC, 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
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circuits. Such voltage measurements include signal levels, special
equipment, limited-energy parts of equipment, circuits powered
by regulated low-voltage sources, and electronics.
Caution If using in Division 2 or Zone 2 hazardous
locations applications, do not connect the NI 9238 to
signals or use for measurements within Measurement
Categories II, III, or IV.
Measurement Category II is for measurements performed on
circuits directly connected to the electrical distribution system.
This category refers to local-level electrical distribution, such as
that provided by a standard wall outlet, for example, 115 V for
U.S. or 230 V for Europe.
Caution Do not connect the NI 9238 to signals or use
for measurements within Measurement Categories III
or IV.
Note Measurement Categories CAT I and CAT O 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.
NI 9238 Getting Started Guide | © National Instruments | 5

Safety Guidelines for Hazardous Voltages
If hazardous voltages are connected to the device, take the
following precautions. A hazardous voltage is a voltage greater
than 42.4 Vpk voltage or 60 VDC to earth ground.
Caution Ensure that hazardous voltage wiring is
performed only by qualified personnel adhering to local
electrical standards.
Caution Do not mix hazardous voltage circuits and
human-accessible circuits on the same module.
Caution Ensure that devices and circuits connected to
the module are properly insulated from human contact.
Caution When module terminals are hazardous
voltage LIVE (>42.4 Vpk/60 VDC), you must ensure
that devices and circuits connected to the module are
properly insulated from human contact. You must use
the NI 9971 connector backshell kit to ensure that the
terminals are not accessible.
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Safety Guidelines for Hazardous Locations
The NI 9238 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
and Ex nA IIC T4 hazardous locations; and nonhazardous
locations only. Follow these guidelines if you are installing the
NI 9238 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.
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.
Caution For Division 2 and Zone 2 applications,
install the system in an enclosure rated to at least IP54
as defined by IEC/EN 60079-15.
NI 9238 Getting Started Guide | © National Instruments | 7

Caution For Division 2 and Zone 2 applications,
connected voltage sources must be within 60 VDC to
earth ground.
Caution For Division 2 and Zone 2 applications,
install a protection device between the input signal and
the NI 9238 input terminal. The device must clamp all
voltage sources to no more than 40% above their rated
value or within 84 VDC to earth ground if there is a
transient overvoltage condition.
Special Conditions for Hazardous Locations Use in
Europe and Internationally
The NI 9238 has been evaluated as Ex nA IIC T4 Gc equipment
under DEMKO Certificate No. 12 ATEX 1202658X and is
IECEx UL 14.0089X certified. Each NI 9238 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 9238
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.
Caution You must make sure that transient
disturbances do not exceed 140% of the rated voltage.
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Caution The system shall only be used in an area of
not more than Pollution Degree 2, as defined in
IEC 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.
Electromagnetic Compatibility 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
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
NI 9238 Getting Started Guide | © National Instruments | 9

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.
Caution To ensure the specified EMC performance,
operate this product only with shielded cables and
accessories.
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Cable Requirements for EMC Compliance
Install cables for the NI 9238 in accordance with the following
requirements:
• Connect the cable shield to the chassis ground (grounding
screw of the chassis).
• Install an EMI Noise-Suppression Ferrite (part number
782802-01) on the input cable for each channel connected to
the NI 9238.
• Position the ferrite as close to the module as possible. Placing
the ferrite elsewhere decreases its effectiveness.
NI 9238 Getting Started Guide | © National Instruments | 11

Figure 1. NI 9238 Cable Connections for EMC Compliance
NI 9238
Shield
AI0+
AI0–
Ferrite
Shield
AI1+
AI1–
Ferrite
Shield
AI2+
AI2–
Ferrite
Signal
Source
Signal
Source
Signal
Source
Shield
AI3+
AI3–
Ferrite
Signal
Source
Related Information
NI 9238 Connection Guidelines on page 17
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Special Conditions for Marine Applications
Some products are Lloyd’s Register (LR) Type Approved for
marine (shipboard) applications. To verify Lloyd’s Register
certification for a product, visit ni.com/certification and search
for the LR certificate, or look for the Lloyd’s Register mark on
the product.
Caution In order to meet the EMC requirements for
marine applications, install the product in a shielded
enclosure with shielded and/or filtered power and
input/output ports. In addition, take precautions when
designing, selecting, and installing measurement probes
and cables to ensure that the desired EMC performance
is attained.
NI 9238 Getting Started Guide | © National Instruments | 13

Preparing the Environment
Ensure that the environment in which you are using the NI 9238
meets the following specifications.
Operating temperature
(IEC 60068-2-1, IEC 60068-2-2)
-40 °C to 70 °C
Operating humidity
(IEC 60068-2-78)
10% RH to 90% RH,
noncondensing
Pollution Degree 2
Maximum altitude15,000 m
Indoor use only.
Note Refer to the device datasheet on ni.com/manuals
for complete specifications.
1Refer to the Safety Voltages section for more information about altitude.
14 | ni.com | NI 9238 Getting Started Guide

NI 9238 Pinout
AI0+
AI0–
AI1+
AI1–
AI2+
AI2–
AI3+
AI3–
0
1
0
1
0
1
0
1
NI 9238 Getting Started Guide | © National Instruments | 15

Table 1. Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection
Grounded Connections
NI 9238
Signal Source
AI–
+
–
AI+
Make sure the voltage on the AI+ and AI- connections are in the
channel-to-earth safety voltage range to ensure proper operation.
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Floating Connections
NI 9238
Signal Source
AI–
+
–
AI+
NI 9238 Connection Guidelines
• Make sure that devices you connect to the NI 9238 are
compatible with the module specifications.
• You must use 2-wire ferrules to create a secure connection
when connecting more than one wire to a single terminal on
the NI 9238.
Related Information
Cable Requirements for EMC Compliance on page 11
NI 9238 Getting Started Guide | © National Instruments | 17

High-Vibration Application Connections
If your application is subject to high vibration, NI recommends
that you follow these guidelines to protect connections to the
NI 9238:
• Use ferrules to terminate wires to the detachable connector.
• Use the NI 9971 backshell kit.
Overvoltage Protection
The NI 9238 provides overvoltage protection for each channel.
Note Refer to the device datasheet on ni.com/manuals
for more information about overvoltage protection.
18 | ni.com | NI 9238 Getting Started Guide

Where to Go Next
Located at ni.com
/
manuals Installs with the software
CompactRIO NI CompactDAQ
RELATED INFORMATION
NI 9238 Datasheet
NI-RIO Help
LabVIEW FPGA Help
NI 9238 Datasheet
NI-DAQmx Help
LabVIEW Help
C Series
Documentation
& Resources
ni.com
/
info
cseriesdoc
Servi ces
ni.com/services
NI 9238 Getting Started Guide | © National Instruments | 19

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 NI Factory Installation Services, repairs,
extended warranty, and other services.
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.
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