cDAQ Module Support for Accessing On-board Counters

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.

Contents

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
ModelChType>RangeDescriptionRate

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
ModelChType>RangeDescriptionRate

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

 

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