cDAQ Module Support for Accessing On-board Counters

Updated Mar 20, 2025

Overview

This article explains which NI C Series modules you can use to access the counters or timers on your CompactDAQ (cDAQ) chassis or controller's backplane. Use this article if you want to use a quadrature encoder or other sensor to measure frequency, period, pulse width, semi period, two edge separation, position, velocity, duty cycle, or count edges with your cDAQ chassis or controller. You can also use these counters to generate a pulse width modulation signal (PWM), pulse train or patterns.

Introduction
Modules That Can Access Counters
Modules That Can Not Access Counters
Additional Resources

Introduction

The NI cDAQ chassis contains four 32-bit counters in the backplane that perform both input and output tasks. To access the Source, Gate, Out, and other auxiliary lines you will need to install a parallel, hardware-timed, digital I/O module. With the exception of the cDAQ-9172, which requires the module to be placed in slot 5 or 6 only, the module may be used in any slot of any other cDAQ chassis. Digital input modules will have access to the counter inputs, and digital output modules will have access to the counter outputs. Bidirectional digital modules will have access to both. Once you have inserted the module, you can configure counter tasks through the driver.

Modules That Can Access Counters

Modules That Can Access Counters
Model	Ch	Type	>Range	Description	Rate
NI 9344	8	Parallel	N/A	Input/Output	N/A
NI 9361*	8	Parallel	5 / 24 V	Input	1 MHz
NI 9401	8	Parallel	5V TTL	Bidirectional	10 MHz
NI 9402**	4	Parallel	LVTTL	Bidirectional	16 MHz**
NI 9411	6	Parallel	5-24 V	Input	2 MHz
NI 9421	8	Parallel	24 V	Input (sink)	10 kHz
NI 9422	8	Parallel	24-60 V	Input (sink/source)	4 kHz
NI 9423	8	Parallel	24-30 V	Input (sink)	1 MHz
NI 9435	4	Parallel	5-250 V	Input (sink/source)	357 Hz
NI 9436	8	Parallel	250 V	Input (sink/source)	50 Hz
NI 9437	8	Parallel	24-250 V	Input (sink)	1 MHz
NI 9472	8	Parallel	6-30 V	Output (source)	10 kHz
NI 9474	8	Parallel	5-30 V	Output (source)	1 MHz
NI 9475	8	Parallel	5-60 V	Output (source)	1 MHz
NI 9481	4	Parallel	60/250 V	Output (source)	1 Hz
NI 9482	4	Parallel	60/250 V	Output (source)	1 Hz
NI 9485	8	Parallel	60/30 V	Output (source)	1 Hz

* The NI 9361 is not actually able to access the chassis on-board counters, but it is the only module that has built-in counters itself; that is the reason it is included on this list

** The NI 9402 can operate at 20 MHz if two or fewer channels are used

Modules That Can Not Access Counters

Modules That Can Not Access Counters
Model	Ch	Type	>Range	Description	Rate
NI 9375	16/16	Serial	12, 24 V	Input/Output	140 kHz*
NI 9403	32	Serial	5V TTL	Bidirectional	1 kHz
NI 9425	32	Serial	24 V	Input (sink)	140 kHz
NI 9426	32	Serial	24 V	Input (source)	140 kHz
NI 9476	32	Serial	6-36 V	Output (source)	2 kHz
NI 9477	32	Serial	5-60 V	Output (sink)	125 kHz
NI 9478	16	Serial	5-50 V	Output (sink)	20 kHz

*The NI 9375 has a 140 kHz Input (sinking) rate a 2 kHz Output (sourcing) rate

Additional Resources

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