C Series Digital Input and Counter/Timer Modules

Overview

High-performance digital input switching modules for National Instruments

CompactRIO embedded systems, R Series expansion chassis, and

NI CompactDAQ provide industrial logic levels for direct connection

to a wide array of industrial automotive switches and transducers. Each

module features an integrated connector junction box with screw terminal

or cable options for flexible and low-cost signal wiring. All modules

feature the NI CompactRIO Extreme Industrial Certifications and Ratings.

System Compatibility

You can use NI C Series modules in multiple system types depending

on available software. See Table 1 for CompactRIO and NI CompactDAQ

module compatibility because not all modules work with both systems.

Many of the advanced features described apply only to reconfigurable

I/O systems and not to NI CompactDAQ.

Advanced Features

When used in CompactRIO, C Series digital input modules connect directly

to reconfigurable I/O (RIO) FPGA hardware to create high-performance

embedded systems. The reconfigurable FPGA hardware within CompactRIO

provides a variety of options for timing, triggering, synchronization, change

detection, digital pattern matching, or digital communication. For instance,

with CompactRIO you can implement a circuit to detect digital events

and record a timestamp, implement high-reliability digital control logic

in silicon, or perform redundant safety enforcement and interlocks. Unlike

traditional digital control devices, the performance of a CompactRIO

digital control system does not decrease as the amount of digital logic

increases because of the parallel nature of the RIO FPGA circuitry.

Key Features

• High-performance digital and counter/timer input modules for CompactRIO

embedded system, R Series expansion chassis, or NI CompactDAQ system

• Screw terminal, D-Sub, strain relief, high-voltage cable,

solder-cup backshell, and other connectivity options

• NI CompactRIO Extreme Industrial Certifications and Ratings

• NI 9411 module that generates regulated 5 V power for quadrature

encoder or other devices

• Channel-to-earth ground double-isolation barrier for safety

and noise immunity and channel-to-channel isolation

information on module availability, example programs, application notes,

and other developer tools.

Typical certifications – Actual specifications vary from product to

North American

Hazardous Locations

• High- and low-speed 24 V logic

(IEC 1131-2), 5 V/TTL, differential/

single-ended inputs, or universal

AC/DC inputs up to 250 VAC/VDC

• Channel-to-channel isolation

• Up to 100 ns input rate for ultrahigh-

speed digital communication

• Up to 500 ns input rate

for high-speed control

or long-distance

digital communication

• Internal current limiting and

industrial logic thresholds

for direct connection to a

wide array of industrial

switches, encoders,

and transducers

Compatibility

Product

CompactRIO

NI CompactDAQ

Logic

Channels

Source/Sink

I/O Delay Time

Signal Levels

Isolation

Connector Options

NI 9401





5 V/TTL

8

Sink/Source

100 ns

5 V



D-Sub

NI 9411





Differential or 5 V/TTL

6

–

500 ns

±5 to ±24 V



D-Sub

NI 9421





24 V

8

Sink

100 µs

24 V



Screw Terminal, D-Sub

NI 9422





24 V

8

Sink/Source

250 µs

Up to 60 V

 (ch-to-ch)

Screw Terminal

NI 9423





24 V

8

Sink

1 µs

24 V



Screw Terminal

NI 9425





24 V

32

Sink

7 µs

24 V



D-Sub

NI 9435





Universal

4

Sink/Source

3 ms

±5 to 250 VDC, 10 to 250 VAC



Screw Terminal

Table 1. C Series Digital Input and Counter/Timer Module Selection Guide