National Instruments NI 9226 User manual

GETTING STARTED GUIDE
NI 9226
8 RTD, 0 Ω to 4,000 Ω, 24 Bit, 400 S/s
Aggregate, PT1000

This document explains how to connect to the NI 9226. In this
document, the NI 9226 with spring terminal and the
NI 9226 with DSUB are referred to inclusively as the NI 9226.
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 9226. 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 9226 only as described in this document.
Caution Do not operate the NI 9226 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
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way. If the product is damaged, return it to NI for
repair.
Hazardous Voltage This icon denotes a warning
advising you to take precautions to avoid electrical
shock.
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.
You can connect hazardous voltages only to the
NI 9226 with spring terminal. Do not connect hazardous voltages
to the NI 9226 with DSUB.
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.
NI 9226 Getting Started Guide | © National Instruments | 3

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.
Safety Voltages
Connect only voltages that are within the following limits.
NI 9226 with Spring Terminal Isolation Voltages
Channel-to-channel None
Channel-to-earth ground
Continuous 250 Vrms,
Measurement Category II
Withstand 3,000 Vrms, verified by a 5 s
dielectric withstand test
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.
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Caution Do not connect the NI 9226 to signals or use
for measurements within Measurement Categories III
or IV.
NI 9226 with DSUB Isolation Voltages
Channel-to-channel None
Channel-to-earth ground
Continuous 60 VDC,
Measurement Category I
Withstand
Up to 3,000 m 1,000 Vrms, verified by a 5 s
dielectric withstand test
up to 5,000 m 860 Vrms, verified by a 5 s
dielectric withstand test
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
NI 9226 Getting Started Guide | © National Instruments | 5

equipment, limited-energy parts of equipment, circuits powered
by regulated low-voltage sources, and electronics.
Note Do not connect the NI 9226 with DSUB to
signals or use for measurements within Measurement
Categories II, III, or IV.
Caution Do not connect the NI 9226 to signals or use
for measurements within Measurement Categories II,
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.
Safety Guidelines for Hazardous Locations
The NI 9226 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 9226 in a potentially explosive environment. Not following
these guidelines may result in serious injury or death.
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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.
Special Conditions for Hazardous Locations Use in
Europe and Internationally
The NI 9226 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 9226 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 9226
in Gas Group IIC hazardous locations, you must use the device in
NI 9226 Getting Started Guide | © National Instruments | 7

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.
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
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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.
Caution To ensure the specified EMC performance,
operate this product only with shielded cables and
accessories. Do not use unshielded cables or
accessories unless they are installed in a shielded
enclosure with properly designed and shielded input/
output ports and connected to the product using a
shielded cable. If unshielded cables or accessories are
NI 9226 Getting Started Guide | © National Instruments | 9

not properly installed and shielded, the EMC
specifications for the product are no longer guaranteed.
Caution To ensure the specified EMC performance of
the NI 9226 with spring terminal, cable shields must be
connected to the ground lug of the chassis using a wire
of minimum practical length.
Caution The pins of the NI 9226 with spring terminal
can be damaged if subjected to Electrostatic Discharge
(ESD). To prevent damage either install the NI 9440
connector backshell kit or employ industry-standard
ESD prevention measures during installation,
maintenance, and operation.
Caution To ensure the specified EMC performance of
the NI 9226 with DSUB, the length of all I/O cables
must be no longer than 30 m (100 ft).
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
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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.
Preparing the Environment
Ensure that the environment in which you are using the NI 9226
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 altitude 5,000 m
NI 9226 Getting Started Guide | © National Instruments | 11

Indoor use only.
Note Refer to the device datasheet on ni.com/manuals
for complete specifications.
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NI 9226 Pinout
NC
EX0+
RTD0+
RTD0-
COM
EX1+
RTD1+
RTD1-
COM
EX2+
RTD2+
RTD2-
COM
EX3+
RTD3+
RTD3-
COM
NC
NC
EX4+
RTD4+
RTD4-
COM
EX5+
RTD5+
RTD5-
COM
EX6+
RTD6+
RTD6-
COM
EX7+
RTD7+
RTD7-
COM
NC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
RTD0+
COM0
RTD1+
COM1
RTD2+
COM2
RTD3+
COM3
NC
NC
RTD4+
COM4
RTD5+
COM5
RTD6+
COM6
RTD7+
COM7
EX0+
RTD0-
EX1+
RTD1-
EX2+
RTD2-
EX3+
RTD3-
NC
NC
EX4+
RTD4-
EX5+
RTD5-
EX6+
RTD6-
EX7+
RTD7-
NC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
NI 9226 Getting Started Guide | © National Instruments | 13

Table 1. Signal Descriptions
Signal Description
COM Common reference connection to isolated ground
EX+ Positive sensor excitation connection
NC No connection
RTD+ Positive resistance temperature detector connection
RTD- Negative resistance temperature detector connection
Connecting 3-Wire and 4-Wire RTDs
You can connect any combination of 3-wire or 4-wire RTDs to
the NI 9226. Each NI 9226 channel contains circuitry that
automatically detects the type of RTD connected to the channel.
The NI 9226 scans all eight input channels and automatically
configures each channel for the appropriate mode. In 4-wire
mode, the EX terminal is a 0.1 mA current source. In 3-wire
mode, the RTD+ terminal is a 0.1 mA current source. The
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NI 9226 compensates for the error that lead resistance causes in
3-wire mode.
If you are using a 4-wire RTD, connect EX to the positive lead of
the RTD. If you are using a 3-wire RTD, do not connect the RTD
to the EX terminal.
Figure 1. Connecting an RTD to the NI 9226
NI 9226
4-Wire EX
RTD+
RTD–
COM
RTD
For the best measurement results when using the NI 9226 with a
3-wire RTD, use equal-length wires between the RTD+ terminal
and the RTD and between the COM terminal and the RTD. Also,
keep the lead resistance within 5% of the nominal RTD value.
The NI 9226 accuracy specifications account for this lead error.
NI 9226 Getting Started Guide | © National Instruments | 15

Note The accessory used with the NI 9226 may
introduce additional lead resistance mismatch error in
3-wire mode. Refer to the device datasheet on ni.com/
manuals for information about errors due to lead
resistance mismatch.
NI 9226 Connection Guidelines
Make sure that devices you connect to the NI 9226 are
compatible with the module specifications.
Connecting to a Spring-Terminal Connector
What to Use
• NI 9226 spring-terminal connector
• 0.08 mm2 to 1.0 mm2 (28 AWG to 18 AWG) copper
conductor wire with 7 mm (0.28 in.) of insulation stripped
from the end
• Flathead screwdriver with a 2.3 mm x 1.0 mm (0.09 in. x
0.04 in.) blade, included with the NI 9226
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What to Do
Complete the following steps to connect wires to the spring-
terminal connector.
1 2 3
1. Insert the screwdriver into a spring clamp activation slot to
open the corresponding connector terminal.
2. Press a wire into the open connector terminal.
NI 9226 Getting Started Guide | © National Instruments | 17

3. Remove the screwdriver from the activation slot to clamp the
wire into place.
High-Vibration Application Connections
If your application is subject to high vibration, NI recommends
that you use the NI 9940 backshell kit to protect connections to
the NI 9226 with spring terminal.
Installing the NI 9940
To meet the EMC guidelines in this document and the
Electromagnetic Compatibility specifications in the NI 9226
Datasheet, you must use the NI 9940 connector backshell kit.
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Figure 2. NI 9940 Connector Backshell Installation
NATIONAL
INSTRUMENTS
1. Install the NI 9940 backshell on the 36-pin spring-terminal
connector.
NI 9226 Getting Started Guide | © National Instruments | 19

2. Tighten the NI 9940 backshell screws to 0.45 N · m
(4.0 lb · in) torque.
Related Information
Electromagnetic Compatibility Guidelines on page 8
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