National Instruments NI 9474 User manual

NI-9474 Getting
Started
2022-07-06

Contents
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Safety Guidelines for Hazardous Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Safety Guidelines for Hazardous Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electromagnetic Compatibility Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Special Conditions for Marine Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Preparing the Environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
NI 9474 Pinout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Connecting Digital Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Increasing Current Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
High-Vibration Application Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
I/O Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power Supplies and Overcurrent Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Detecting an Overcurrent Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Resetting Channels aer an Overcurrent Condition. . . . . . . . . . . . . . . . . . . . . . . . 10
Where to Go Next. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
NI Services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
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NI-9474 Getting Started

Overview
This document explains how to connect to the NI-9474. In this document, the
NI-9474 with screw terminal and the NI-9474 with spring terminal are referred to
inclusively as the NI-9474.
Note Before you begin, read the NI-9474 Safety, Environmental, and
Regulatory Information document on ni.com/manuals and complete the
soware and hardware installation procedures in your chassis
documentation.
Note The guidelines in this document are specific to the NI-9474. 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
Caution Observe all instructions and cautions in the user documentation.
Using the product in a manner not specified can damage the product and
compromise the built-in safety protection.
Attention Suivez toutes les instructions et respectez toutes les mises
en garde de la documentation d'utilisation. L'utilisation du produit de
toute autre façon que celle spécifiée risque de l'endommager et de
compromettre la protection de sécurité intégrée.
Safety Voltages
Connect only voltages that are within the following limits.
Channel-to-COM 30 V DC maximum
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NI-9474 Getting Started

External power supply (Vsup) voltage range 5 V DC to 30 V DC
Isolation
Channel-to-channel None
Channel-to-earth ground
Continuous 250 V RMS, Measurement Category II
Withstand 2,300 V RMS, verified by a 5 s dielectric withstand test
Caution Do not connect the product to signals or use for measurements
within Measurement Categories III or IV.
Attention Ne pas connecter le produit à des signaux dans les catégories
de mesure III ou IV et ne pas l'utiliser pour eectuer des mesures dans ces
catégories.
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.
Safety Guidelines for Hazardous Voltages
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.
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NI-9474 Getting Started

Note When module terminals are hazardous voltage LIVE (>42.4 Vpk/
60 V DC), you must ensure that devices and circuits connected to the
module are properly insulated from human contact. You must use the
NI-9927 connector backshell kit with the NI-9474 with screw terminal and
the NI-9981 connector backshell kit with the NI-9474 with spring terminal
to ensure that the terminals are not accessible.
Safety Guidelines for Hazardous Locations
The NI-9474 is suitable for use in hazardous locations; , and hazardous locations;
and nonhazardous locations only. Follow these guidelines if you are installing the
NI-9474 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 o or the area is known to be nonhazardous.
Caution Do not remove modules unless power has been switched o 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-9474 has been evaluated as equipment under DEMKO ATEX and is IECEx
certified. Each NI-9474 is marked 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-9474
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NI-9474 Getting Started

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 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.
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 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.
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NI-9474 Getting Started

Special Conditions for Marine Applications
Some products are approved for marine (shipboard) applications. To verify marine
approval certification for a product, visit ni.com/product-certifications, search by
model number, and click the appropriate link.
Notice 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-9474 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 2,000 m
Indoor use only.
Note Refer to the device datasheet on ni.com/manuals for complete
specifications.
NI 9474 Pinout
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NI-9474 Getting Started

DO0
DO1
DO2
DO3
DO4
DO5
DO6
DO7
Vsup
COM
0
1
2
3
4
5
6
7
8
9
DO0
DO1
DO2
DO3
DO4
DO5
DO6
DO7
Vsup
COM
0
1
2
3
4
5
6
7
8
9
Note You must use 2-wire ferrules to create a secure connection when
connecting more than one wire to a single terminal on the NI-9474 with
screw terminal or NI-9474 with spring terminal.
Signal Description
COM Common reference connection to isolated ground
DO Digital output signal connection
Vsup Voltage supply connection
Table 1. NI-9474 Signal Descriptions
LED Pattern Indication
Solid The channel has been programmed to be in the ON state.
O The channel has been programmed to be in the OFF state.
Table 2. LED Indicators
Connecting Digital Devices
You can connect a variety of industrial devices, such as solenoids, motors, actuators,
relays, and lamps to the NI-9474. You must connect an external power supply to the
NI-9474. The power supply provides the current for the output channels.
Figure 1. Connecting an Industrial Device to the NI-9474
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NI-9474 Getting Started

Caution Do not install or remove C Series modules from your system if
any external power supplies connected to the Vsup and COM pins are
powered on.
Attention Ne pas installer ou retirer les modules de la Série C de votre
système si une alimentation externe connectée aux broches Vsup et COM
est sous tension.
Ensure that the devices you connect to the NI-9474 are compatible with the output
specifications of the NI-9474. Refer to the device datasheet at ni.com/manuals for
output specifications.
Note When the industrial device is o, DO is not connected to COM. For
large source impedances, you must use a pull-down resistor between DO
and COM. Go to ni.com/r/cseriesdopulsegen for more information.
Increasing Current Drive
Each channel of the NI-9474 has a continuous output current of 1.0 A. If you want to
increase the output current to a device, you can connect any number of channels
together in parallel.
For example, if you want to drive 4 A of current, connect DO0 through DO3 in
parallel, as shown in the following figure. You must turn all parallel channels on and
o simultaneously so that the current on any single channel cannot exceed the 1.0 A
rating.
Figure 2. Increasing the Current to a Device Connected to the NI-9474
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-9474:
■Use ferrules to terminate wires to the detachable connector.
■Use the NI-9927 backshell kit with the NI-9474 with screw terminal or the
NI-9981 backshell kit with the NI-9474 with spring terminal.
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NI-9474 Getting Started

I/O Protection
The NI-9474 provides short-circuit protection.
Each channel has circuitry that protects it from current surges resulting from short
circuits over 14 A.
Note Refer to the device datasheet at ni.com/manuals for maximum
continous output current, short-circuit behavior, and short-circuit trip time
specifications and information about conditions that may damage the
module.
Note Refer to the IEC 61131-2 standard for more information about short-
circuit-proof devices.
Note Because the NI-9474 includes internal flyback diodes, you do not
need to add external diodes when connecting to switching devices that
store energy.
Power Supplies and Overcurrent Conditions
If a short circuit occurs, the current through DO can exceed the current rating for the
power supply and the maximum continuous output current for the NI-9474.
If the power supply you are using with the NI-9474 cannot supply more than 14 A,
the module may be damaged if a short circuit condition occurs.
Detecting an Overcurrent Condition
If a device connected to the module is not working while the channel is on, the
module channel may be in an overcurrent state. Neither the soware nor the
module LEDs indicate if an overcurrent condition occurs. A channel LED may be on
even if the channel is o because of an overcurrent condition.
To determine if the channel is in an overcurrent state, measure the voltage between
DO and Vsup. If the voltage is equal to the voltage of the external power supply
connected to the module, the channel is in an overcurrent state.
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NI-9474 Getting Started