National Instruments NI 9425 User manual

OPERATING INSTRUCTIONS AND SPECIFICATIONS
NI 9425E
32-Channel, 24 V Sinking Digital Input Module

2|ni.com |NI 9425E Operating Instructions and Specifications
This document describes how to use the National
Instruments 9425E and includes dimensions, connector
assignments, and specifications for the NI 9425E. 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 9425E. The end-product supplier is responsible
for conformity to any and all compliance requirements.
Caution The NI 9425E must be installed inside a suitable
enclosure prior to use. Hazardous voltages may be present.
Caution Do not operate the NI 9425E 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 9425E Operating Instructions and Specifications |© National Instruments |3
NI 9425E Dimensions
The following figure shows the dimensions of the NI 9425E.
Figure 1. NI 9425E 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 9425E Operating Instructions and Specifications
Connecting the NI 9425E
The NI 9425E has a 37-pin DSUB connector that provides
connections for 32 simultaneously-sampled digital input channels.
Figure 2. NI 9425E Pin Assignments
DI16
DI17
DI18
DI19
DI20
DI21
DI22
DI23
COM
COM
DI24
DI25
DI26
DI27
DI28
DI29
DI30
DI31
DI0
DI1
DI2
DI3
DI4
DI5
DI6
DI7
COM
COM
DI8
DI9
DI10
DI11
DI12
DI13
DI14
DI15
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 9425E Operating Instructions and Specifications |© National Instruments |5
Each channel has a DI pin to which you can connect a digital input
signal. The NI 9425E has four common pins, COM, that are
internally connected to the isolated reference of the module.
The NI 9425E has sinking inputs, meaning that when the device
drives a current or applies a voltage to the DI pin, the pin provides
a path to COM for the current or voltage. The NI 9425E internally
limits current signals connected to DI. For more information about
input current levels, refer to the Specifications section.
You can connect 2-, 3-, and 4-wire sourcing-output devices to
the NI 9425E. A sourcing-output device drives current or applies
voltage to the DI pin. An example of a sourcing-output device is an
open collector PNP.

6|ni.com |NI 9425E Operating Instructions and Specifications
Connect the sourcing-output device to the DI pin on the NI 9425E.
Connect the common of the external device to the COM pin. Refer
to Figure 3 for an illustration of connecting a device to the
NI 9425E.
Figure 3. Connecting a Device to the NI 9425E
(Three-Wire Device Shown)
The NI 9425E channel registers as ON when the sourcing-output
device applies a voltage or drives a current that is in the input ON
range to the DI pin. The channel registers as OFF when the device
applies a voltage or drives a current that is in the input OFF range
to the DI pin. If no device is connected to the DI pin, the channel
NI 9425
+
_COM
DI
Sourcing-Output
Device
External
Power
Supply

NI 9425E Operating Instructions and Specifications |© National Instruments |7
registers as OFF. Refer to the Specifications section for more
information about the ON and OFF states.
Caution To ensure a grounded connection, use shielded
I/O cables and tie the shield to the chassis ground.
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.

8|ni.com |NI 9425E Operating Instructions and Specifications
Specifications
The following specifications are typical for the range -40 to 70 °C
unless otherwise noted. All voltages are relative to COM unless
otherwise noted.
Input Characteristics
Number of channels.......................... 32 digital input channels
Input type .......................................... Sinking
Digital logic levels
OFF state
Input voltage ........................ ≤5 V
Input current......................... ≤150 μA
ON state
Input voltage ........................ ≥10 V
Input current......................... ≥330 μA
Hysteresis
Input voltage ........................ 2 V min
Input current......................... 60 μA min
Input impedance................................ 30 kΩ± 5%

NI 9425E Operating Instructions and Specifications |© National Instruments |9
I/O protection
Input voltage
8 channels ............................ 60 VDC max
32 channels .......................... 30 VDC max
Reverse-biased voltage
8 channels ............................ -60 VDC max
32 channels .......................... -30 VDC max
Hold time1......................................... 0 μs min
Setup time2........................................ 1 μs min
Update/transfer time ......................... 7 μs max
MTBF ............................................... 1,256,699 hours at 25 °C;
Bellcore Issue 2, Method 1,
Case 3, Limited Part Stress
Method
1 Hold time is the amount of time input signals must be stable after initiating a read
from the module.
2 Setup time is the amount of time input signals must be stable before reading from the
module.

10 |ni.com |NI 9425E Operating Instructions and Specifications
Note Contact NI for Bellcore MTBF specifications
at other temperatures or for MIL-HDBK-217F
specifications.
Power Requirements
Power consumption from chassis
Active mode ............................... 410 mW max
Sleep mode ................................. 0.5 mW max
Thermal dissipation (at 70 °C)
Active mode ............................... 1.45 W max
Sleep mode ................................. 1 W max
Physical Characteristics
If you need to clean the module, wipe it with a dry towel.
Weight............................................... 43 g (1.5 oz)
Safety
Safety Voltages
Connect only voltages that are within the following limits.
Channel-to-COM .............................. 60 VDC max