National Instruments NI 9476E User manual

OPERATING INSTRUCTIONS AND SPECIFICATIONS
NI 9476E
32-Channel, 24 V Sourcing Digital Output Module

2|ni.com |NI 9476E Operating Instructions and Specifications
This document describes how to use the National Instruments 9476E
and includes dimensions, connector assignments, and specifications for
the NI 9476E. Visit ni.com/info and enter rdsoftwareversion
to determine which software you need for the modules you are using.
For information about installing, configuring, and programming the
system, refer to the system documentation. Visit ni.com/info and
enter cseriesdoc for information about C Series documentation.
Caution National Instruments makes no electromagnetic
compatibility (EMC) or CE marking compliance claims
for the NI 9476E. The end-product supplier is responsible
for conformity to any and all compliance requirements.
Caution The NI 9476E must be installed inside a suitable
enclosure prior to use. Hazardous voltages may be present.
Caution Do not operate the NI 9476E in a manner not
specified in these operating instructions. 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 National
Instruments for repair.

NI 9476E Operating Instructions and Specifications |© National Instruments |3
NI 9476E Dimensions
The following figure shows the dimensions of the NI 9476E.
Figure 1. NI 9476E Dimensions in Millimeters (Inches)
73.4 (2.89)
0.0 (0.00)
26.7 (1.05)
58.4 (2.30)
66.0 (2.60)
0.0 (0.00)

4|ni.com |NI 9476E Operating Instructions and Specifications
Connecting the NI 9476E
The NI 9476E has a 37-pin DSUB connector that provides
connections for 32 digital output channels.
Figure 2. NI 9476E Pin Assignments
DO16
DO17
DO18
DO19
DO20
DO21
DO22
DO23
Vsup
Vsup
DO24
DO25
DO26
DO27
DO28
DO29
DO30
DO31
DO0
DO1
DO2
DO3
DO4
DO5
DO6
DO7
Vsup
Vsup
DO8
DO9
DO10
DO11
DO12
DO13
DO14
DO15
COM
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 9476E Operating Instructions and Specifications |© National Instruments |5
Each channel has a DO pin to which you can connect a digital input
device. The 32 digital output channels are internally referenced
to COM.
You must connect an external power supply to the NI 9476. The
power supply provides the current for the output channels. Connect
the positive lead of the power supply to the supply pin, Vsup, and
the negative lead of the power supply to the common pin, COM.
Refer to the Specifications section for information about the power
supply voltage range.
Note The Vsup pins are internally connected. You can
connect only one external voltage supply to the device.
Caution Do not remove or insert modules if the external
power supply connected to the Vsup and COM pins is
powered on.
The NI 9476 has current sourcing outputs, meaning the DO pin is
driven to Vsup when the channel is turned on.

6|ni.com |NI 9476E Operating Instructions and Specifications
You can directly connect the NI 9476 to a variety of industrial
devices such as solenoids, motors, actuators, relays, and lamps.
Make sure the devices you connect to the NI 9476 are compatible
with the output specifications of the module. Refer to the
Specifications section for more information about the output
specifications.
Connect the device to DO and COM, and connect the external
power supply to Vsup and COM, as shown in Figure 3.
Figure 3. Connecting a Device to the NI 9476
Caution To ensure a grounded connection, use shielded
I/O cables and tie the shield to the chassis ground.
NI 9476
+
_
COM
Vsup
Device
DO External
Power
Supply

NI 9476E Operating Instructions and Specifications |© National Instruments |7
Increasing Current Drive
Each channel has a continuous output current of 250 mA. 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 1 A of current, connect DO <0..3> in parallel as
shown in Figure 4. You must turn all parallel channels on and off
simultaneously so that the current on any single channel cannot
exceed the 250 mA rating.
Figure 4. Increasing the Current to a Device Connected to the NI 9476
NI 9476
250 mA
250 mA
250 mA
250 mA
DO3
DO1
DO0
DO2
1 A
+
_
Device
COM
External
Power
Supply
V
sup

8|ni.com |NI 9476E Operating Instructions and Specifications
Protecting the Module from Flyback Voltages
If the module is switching an inductive or energy-storing device
such as a solenoid, motor, or relay, and the device does not have
flyback protection, install an external flyback diode as shown in
Figure 5.
Figure 5. Connecting a Flyback Diode to the NI 9476
External
Power
Supply
NI 9476
+
_
COM
Vsup
Inductive
Device
DO
Flyback
Diode

NI 9476E Operating Instructions and Specifications |© National Instruments |9
I/O Protection
The NI 9476 is protected against overcurrent, inrush, and
short-circuit conditions in accordance with IEC 1131-2.
Understanding Protected Devices
Each channel on the NI 9476 has circuitry that protects it from
voltage and current surges resulting from short circuits.
Caution The NI 9476 can be damaged under overvoltage
and reverse bias voltage conditions. Check the voltage
specifications for all devices that you connect to the
NI 9476.
Excessive current through a DO pin causes the channel to go into
an overcurrent state. In an overcurrent state, the channel cycles off
and on until the short circuit is removed or the current returns to an
acceptably low level. Refer the Specifications section for typical
trip currents.
Each channel has a status line that indicates in software whether
the channel is in an overcurrent state. Refer to the software help for
information about reading output status.

10 |ni.com |NI 9476E Operating Instructions and Specifications
Sleep Mode
This module supports a low-power sleep mode. Support for sleep
mode at the system level depends on the chassis that the module is
plugged into. Refer to the chassis manual for information about
support for sleep mode. If the chassis supports sleep mode, refer to
the software help for information about enabling sleep mode. Visit
ni.com/info and enter cseriesdoc for information about
C Series documentation.
Typically, when a system is in sleep mode, you cannot
communicate with the modules. In sleep mode, the system
consumes minimal power and may dissipate less heat than it does
in normal mode. Refer to the Specifications section for more
information about power consumption and thermal dissipation.