Rockwell Automation 1734-IK User Manual

Encoder/Counter Modules

1734-IJ and 1734-IK

User Manual

Important User Information

SHOCK HAZARD

Solid state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (Publication SGI-1.1 available from your local Rockwell Automation sales office or online at http://literature.rockwellautomation.com/) describes some important differences between solid state equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable.

In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment.

The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and diagrams.

No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual.

Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited.

Throughout this manual, when neces sary, we u se notes t o make you awa re of safety considerations.

WARNING

IMPORTANT

ATTENTION

BURN HAZARD

Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss.

Identifies information that is critical for successful application and understanding of the product.

Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you:

• identify a hazard

• avoid a hazard

• recognize the consequence

Labels may be located on or inside the equipment (such as a drive or motor) to alert people that dangerous voltage may be present.

Labels may be located on or inside the equipment (such as a drive or motor) to alert people that surfaces may be dangerous temperatures.

POINT I/O, POINTBus, and RSLogix 5000 are trademarks of Rockwell Automation. ControlNet is a trademark of ControlNet International, Ltd. DeviceNet is a trademark of Open DeviceNet Vendor Association, Inc.

Summary of Changes

This publication contains new and revised information not in the last release.

New and Revised Information

See the table for a summary of the major changes in this manual.

Chapter Change

2 Addition of Before You Begin section

Addition of attention and warning statements Update of the Communicate with Your Module section

Appendix A Addition of information on how to configure modules in

RSLogix 5000

Change Bars

W e marked with change bars (as shown with this paragraph) the areas in this manual that are different from previous editions and indicate the addition of new or revised information.

1 Publication 1734-UM006B-E N-P - August 2005

Summary of Changes 2

Notes:

Publication 1734-UM006B-EN-P - August 2005

Preface

About the Modules

Preface

Purpose of This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . P-1

Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . P-1

Related Products and Documentation. . . . . . . . . . . . . . . . . P-1

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-3

Chapter 1

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 1-1

Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Counter Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Encoder Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Period/Rate Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Operation of Scalar . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Rate Measurement Mode . . . . . . . . . . . . . . . . . . . . . . . 1-7

New Data Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Default Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Operating Mode Features . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Operating Mode Features. . . . . . . . . . . . . . . . . . . . . . . 1-9

Install the Modules

Chapter 2

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 2-1

Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Install the Mounting Base/Wiring Base Assembly . . . . . . . . 2-1

Install an I/O Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Install the Removable Terminal Block . . . . . . . . . . . . . . . . 2-4

Remove a Mounting Base . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Wire the Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Communicate with the Modules. . . . . . . . . . . . . . . . . . . . . 2-6

Default Data Map for the 1734-IJ/IK Counter Module . . 2-6

Configure Your Encoder/Counter Module . . . . . . . . . . . . . 2-7

Counter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Filter Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Scalar Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

v Publicat ion 1734-UM006B-EN-P - Augus t 200 5

Input and Output Data

Chapter 3

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 3-1

Data Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Detailed Description of Data Table Information . . . . . . . . . 3-2

Stored/Accumulated Channel Data (Input Word 2) . . . . 3-2

Module/Channel Status and Programming Error Codes

(Input Words 3 and 4) . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Configuration Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Counter Configuration (Configuration Word 1) . . . . . . . 3-5

Filter Selection (Configuration Word 2 . . . . . . . . . . . . . 3-5

Decimal Position (Configuration Word 3) . . . . . . . . . . . 3-6

Word 4 is reserved. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Time Base and Gate Interval (Configuration Words

5 and 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Scalar (Configuration Word 7) . . . . . . . . . . . . . . . . . . . 3-7

Scalar Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Rollover (Configuration Word 8). . . . . . . . . . . . . . . . . . 3-7

Preset (Configuration Word 9) . . . . . . . . . . . . . . . . . . . 3-7

Safe State Values (Configuration Word 10) . . . . . . . . . . 3-8

Communicate Real Time/Nonreal Time Information . . . . . . 3-8

Configure Your Module

Access Instantiated Instances

Troubleshoot with the Indicators

Configure Modules in RSLogix 5000

Chapter 4

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 4-1

Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Add the Adapter to Your Network . . . . . . . . . . . . . . . . 4-1

Add I/O Modules to Your Network. . . . . . . . . . . . . . . . 4-2

Set Counter Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Check I/O Status and View/Edit the EDS File. . . . . . . . . . . 4-6

Chapter 5

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 5-1

Using Instantiated Instances. . . . . . . . . . . . . . . . . . . . . . . . 5-1

Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Chapter 6

What This Chapter Contains . . . . . . . . . . . . . . . . . . . . . . . 6-1

Use the Indicators for Troubleshooting . . . . . . . . . . . . . . . 6-1

Appendix A

What This Appendix Contains . . . . . . . . . . . . . . . . . . . . . . A-1

Understand Data, Connections, and Communication Formats A-1

Configure Your Module. . . . . . . . . . . . . . . . . . . . . . . . . . . A-3

Work with the Fault/Program Action Dialog. . . . . . . . . . . . A-4

Work with the Counter Configuration Dialog . . . . . . . . . . . A-5

Index

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Preface

Purpose of This Manual

Who Should Use This Manual

Read this manual for information about how to install, configure and troubleshoot your Encoder/Counter module.

For This Information: See:

About the Modules Chapter 1 Install the Modules Chapter 2 Encoder/Counter Module Input and Output Data Chapter 3 Configure Your Encoder/Counter Module Chapter 4 Access Instantiated Instances Chapter 5 Troubleshoot with the Indicators Chapter 6

You must be able to use RSNetworx software or similar configuration software to set up and calibrate these modules. You must have the capability to download and use Electronic Data Sheet files.

We assume you know how to do this in this manual. If you do not, refer to your software user manuals or online help before attempting to use these modules.

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Preface 2

Definitions

The following define the intended operation of the Encoder/Counter module.

Term Definition

Lead Breakage Typically requires a shunt resistor (across the load) to detect

3 levels of current/input states -

• Open (Wire Off, Device = ?)

• Off (Wire OK, Device Off)

• On (Wire OK, Device On)

This method does not check the input against a time base, only that the device wiring (current loop) is intact

Missing Pulse Typically uses an input pulse to reset a watc hdog timer (fixed

or programmable HW). This method does detect “Lead Breakage”, since a broken wire will time-out the watchdog.

Zero Frequency Typically uses an input pulse to calculate an input frequency

and verify it is above an error threshold. This method does detect Lead Breakage, since a broken wire will generate a 0Hz frequency.

Missing Pulse or Zero Frequency will also detect a customer device stuck high or low, since the counter is monitoring for a change in the input state. Currently, the Counter/Encoder Modes do not have Zero Frequency Detection - the A & B inputs are time independent, only looking for input edge changes to increment/decrement the count value.

The Period/Rate and Continuous Rate modes do have Zero Frequency Detection, since the Z input is monitored for Zero Frequency in Firmware (A and B inputs are not used and not monitored).

The Rate Measurement mode inherently has Zero Frequency Detection, since no A pulses in any sample period are = 0Hz (B and Z inputs are not used and not monitored).

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Preface 4

Operational Mode Zero Frequency Detection Input Monitored

Counter No None Encoder No None Period/Rate Yes Z Only Rate Measurement Y A Only

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About the Modules

Chapter

What This Chapter Contains

Module Description and Features

Read this chapter to learn about types, features, and capabilities of encoder/counter modules.

Encoder/counter modules install into the Point I/O terminal base (1734-TB or 1734-TBS) and interface with the Point I/O DeviceNet Pass-through (1734-PDN) or the Point I/O DeviceNet Adapter (1734-ADN).

An encoder/counter module serves as a signal conditioner, function block, and counter between the customer process signals on the terminal base and the POINTBus containing the command information. The main functional blocks are the the following.

• Customer digital I/O interface

• Counter ASIC

• Microprocessor

The encoder/counter module accepts feedback from the following.

• Encoders (either single-ended or differential)

• Pulse generators

• Mechanical limit switches

• Frequencies up to 1 MHz

A filter is available with the following settings.

• 50 Hz

• 500 Hz

• 5 kHz

• 50 kHz

Turn the filter off to achieve the fastest counting rate.

The input voltage range is 5V dc (1734-IJ) or 15-24V dc (1734-IK). The module returns the count or frequency in the form of a 24 bit binary number (0 - 16,777,215) expressed in a 32 bit long word.

Each counter has a user-selectable preset and rollover value associated with it.

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1-2 About the Modules

Operating Modes

The encoder/counter modules operate in the modes shown in the table.

Mode Description

Counter Mode Read incoming single phase pulses, return a binary

count

Encoder Mode Read incoming 2 phase quadrature pulses, return a

binary count

Period/Rate Mode Count internal clocks during the On period, return a

frequency

Rate Measurement Mode Read pulses during the sample period, return a

frequency

The operation of the counter and encoder modes is nearly identical. The difference between the two modes is in the type of feedback (1 phase versus 2 phase) for the count direction (up or down).

• In encoder mode, a transition is expected on B for counting to proceed in a direction.

• In counter mode, the B input may be left at a static level.

Select operating modes by writing appropriate configuration data to the module.

Counter Mode

The counter mode reads incoming pulses and returns a binary nu mber (0 - 16,777,215

single phase inputs. The module determines the Phase B input state, and counts up or down accordingly.

Channel A input is used as the counting pulse while chan nel B is used to determine the direction.

[B = High, Count = Down; B = Low or floating (not connected), Count = Up]

The Channel B input may be tied high or low for unidirectional counting, or toggled for bidirectional counting.

) to the POINTBus. The counter mode only accepts

max

Publication 1734-UM006B-EN-P - August 2005

Example of Counter Mode

About the Modules 1-3

ingle Phase Pulse Generator

Count Up Count Down

Input

ount

123

A Input B Direction Z (Store Count)

(Gate / Reset )

210

Input A Input B Input Z

1734-VHSC

Outputs Updated Continuously

Encoder Mode

The encoder mode reads incoming pulses and returns a binary number (0 - 16,777,215

only accepts 2 phase quadrature inputs. The module senses the relationship between the 2 phases, and counts up or down accordingly.

) to the POINTBus. The encoder mode

max

The two basic encoder types are absolute and incremental. A single output incremental encoder is called a tachometer encoder. A dual channel incremental encoder with one channel leading the other by 90° is called a quadrature encoder.

A system using a quadrature encoder may include an optional zero pulse, or index, serving as a reference mark for system reset. The principal disadvantage of a system using incremental en coders is that a power interruption causes the loss of position reference, so a system must be reinitialized or returned to a known zero position.

Absolute encoders typically have higher speed requi rements (200 KHz typical) for motion control applications. An absolute encoder has a unique code associated with each position, so the exact position is always known, even if the system power is turned off.

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1-4 About the Modules

EXAMPLE

Example of Multiplying Encoder Mode X1

Input A Input B

Z (Store Count)

Input Z

Quadrature Encoder

(Gate / Reset )

1734-VHSC

Forward Rotation Reverse Rotation

Input

123

210

1 Count

Count

4 Count

135246

1352467 10981211

531420

11 9 710 8 6 5 23401

Outputs Updated Continuously

X1 Multiplying Encoder Mode

Quadrature input signals are used to count on the leading (up direction) OR trailing (down direction) edge of A for a bidirectional count, and channel B is used to determine the direction.

Publication 1734-UM006B-EN-P - August 2005

[ B = leads A, Count = Down; B = follows A, Count = Up ]

X2 Multiplying Encoder Mode

Quadrature input signals are used to count on leading AND trailing edges of A for a bidirectional count, and channel B is used to determine the direction.

[ B = leads A, Count = Down; B = follows A, Count = Up ]

X4 Multiplying Encoder Mode

Quadrature input signals are used to count on leading AND trailing edges of A AND B for a bidirectional count, and channel B is used to determine the direction.

[ B = leads A, Count = Down; B = follows A, Count = Up ]

About the Modules 1-5

A F F

Period / Rate Mode

The Period/Rate Mode will return an incoming frequency and a total accumulated count to the POINTBus, by g internal clock with an external signal.

This mode determines the frequency and total number of input pulses by counting the number of internal 5MHz clock pulses over a user-specified number of input signal pulses. At the end of the specified number of pulses, the module returns the frequency (0 - 1 MHz).

EXAMPLE

Example of Period/Rate Mode

ating an internal 5MHz

A ( Not Used ) B ( Not Used ) Z

Encoder / Pulse Generator

Z Input ( Pulse )

5 MHz Internal

Sampling Clock

Accumulated Count

ssumes symmetrical pulse, 50% duty cycle, so Period = Sample Time On X 2 {On & Off} requency = 1 / Period If Count = 20, Scalar = 1, and Clock Period = ( 1 / 5 MHz ) requency = 1 / [ ( 20 / 1 ) X ( 1 / 5 MHz ) X 2 ] = 125 kHz

(Gate / Reset )

10 20

Input A Input B Input Z Scalar

5 MHz Clk

1734-IJ/IK

Frequency

Updated Here

As the frequency of the incoming pulse train at the Z (Gate/Reset) terminal increases, the number of sampled pulses from the 5 MHz clock decreases. Since accuracy is related to the number of pulses received over the sample period, the accuracy decreases with increasing frequencies at the Gate/Reset terminal. Refer to the following Scaling table.

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1-6 About the Modules

Relationship Between Sampled Pulses and Input Frequency

Input Frequency at Z Gate/Reset Terminal

2.5Hz 1M 5Hz 500k 10Hz 250k 20Hz 125k 50Hz 50k 100Hz 25k 200Hz 12.5k 500Hz 5k 1kHz 2.5k 2 Hz 1.25k 5kHz 500 10kHz 250 20kHz 125 50kHz 50 100kHz 25

Sample Pulses for 1/2 Cycle of Z Gate/Reset Pulse

Scaling the input frequency through the use of a scalar can lessen the decrease in accuracy. A scalar value of 1 returns an accurate input frequency only if incoming input pulses have a 50% duty cycle.

Operation of Scalar

In the Period/Rate mode, the scalar lets the incoming pulse train at the Z Gate/Reset pin be divided by a user-defined number. There is one scalar value for each counter. Acceptable values for the scalar are 1, 2, 4, 8, 16, 32, 64, and 128. The default value for each scalar is 1. Note that a “0” scalar is equivalent to a “1”.

The product of the Sample Period times the scalar should be less than

6.71 seconds in order to avoid a zero frequency detect indication.

(5 MHz sample time = 200ns; 16,777,216 counts x 200ns x 2 half cycles of Z = 6.71 seconds)

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About the Modules 1-7

Rate Measurement Mode

The Rate Measurement mode determines the frequency and total number of input pulses over a user-specified sample period. At the end of the interval, the module returns a value representing the sampled number of pulses and a value indicating the incoming frequency.

When the count and frequency update, any associated outputs are checked against their associated presets. Frequency is calculated by dividing the accumulated count by the user selected time period, and is returned in the read data. Allowable time periods are 10ms to 3s in 10ms increments, with a default value of 1s. Note that a “0” time period is equivalent to the 1s default.

EXAMPLE

Example of Rate Measurement Mode

A Input B ( Not Used ) Z ( Not Used )

(Gate / Reset )

Encoder/Pulse Generator

A Input ( Pulse )

Internal Sampling Gate Accumulated Count

User Selectable Sample Period,

10ms to 2s in 10ms increments.

If Sample Period is 50ms, and Count = 3, then Frequency = 3 /50ms = 60Hz

Input A Input B Input Z

Time Base

1734-IJ/IK

Frequency Calculated, Updated Here

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1-8 About the Modules

New Data Indicator

A two-bit counter, C1 & C0, updates every time an "event" occurs, indicating that new data is available in the Stored/Accumulated Count words. Definitions for events are as follows.

• Any active gate transition in any of the Store Count (Counter or Encoder) modes

• The end of the gate sample period in either the Period mode or Rate mode

• The end of the programmed sample period in the Rate Measurement mode.

To use these bits reliably, acquisition of data from the Counter Module must occur faster than the events, which cause C1/C0 to increment. When C1/C0 is updated, a Change Of State (COS) message can be sent.

Default Configuration

The module's default configuration on startup is as follows.

• Counter Mode

• 50Hz filter on A, B and Z

• No time base

• Rollover = 0x00FFFFFF

• Preset = 0

• No scalar

• Counter Control Safe State = 0

To modify the default settings to those required for your application, refer to the Input and Output section of this manual.

Publication 1734-UM006B-EN-P - August 2005

About the Modules 1-9

R a

Operating Mode Features

The following table summarizes which features are active in each mode:

Operating Feature Counter

Up / Down

Preset Y Y N N Rollover Y Y N N Software Reset Y Y Y Y Store Count - Z Gate / Reset 4 modes Y Y N N Scale Input Count at Z Gate / Reset N N Y N Z Gate / Reset Invert Bit Y Y Y N Sample Period N N N Y

Encoder X1, X2 & X4

Period /Rate

Rate Measurement

Operating Mode Features

The Z Gate/Reset Terminall will operate in one of four modes when the Store Count feature is in use. The following figures detail the operation in each mode:

• Store/Continue

• Store/Wait/Resume

• Store-Reset/Wait/Start

• Store-Reset/Start

Store Count Mode 1: Store/Continue

In mode 1, the rising edge of a pulse input on the Z Gate/Reset terminal causes the current counter value to be read and stored in the Read Data file. The counter continues counting. The stored count is available in the Stored/Accumulated Count word. The stored count information remains until it is overwritten with new data.

Store/Continue

ead, Store Count, nd Continue Counting

Store Count Mode 2: Store/Wait/Resume

In mode 2, the rising edge of a pulse input on the Z Gate/Reset terminal reads and stores the current counter value in the Stored/Accumulated Count word and inhibits counting while the Z

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1-10 About the Modules

Gate/Reset terminal is high. Counting resumes on the falling edge of the pulse at the Z Gate/Reset terminal. The stored count information remains until it is overwritten with new data.

Store/Wait/Resume

top Counting

tore Count Resume Counti

Store Count Mode 3: Store-Reset/Wait/Start

In mode 3, the rising edge of a pulse input on the Z Gate/Reset terminal stops counting, reads, and stores the current counter value in the Stored/Accumulated Count word, and re sets the counter to zero. The counter does not count while the input pulse o n the Z Gate/Reset terminal is high. Counting resumes from zero on the falling edge of the pulse at the Gate/Reset terminal. The stored count information will remain until it is overwritten with new data.

Store-Reset/Wait/Start

ounter has stopped Counting Stop Count, Store,

and Reset to zero from zero

Start Counti

Store Count Mode 4: Store-Reset/Start

In mode 4, the rising edge of a pulse input on the Z Gate/Reset terminal will store the current counter value in the Stored/Accumulated Count word and reset th e counter to zero. The counter will continue counting while the Z Gate/Reset terminal is high. The stored count information will remain until it is overwritten with new data.

Store-Reset/Start

Start Counting

tore Count, nd Reset to zero

Continue Counti

Publication 1734-UM006B-EN-P - August 2005

Install the Module

Chapter

What This Chapter Contains

Before You Begin

Read this chapter for information about how to install Encoder/ Counter modules.

For information about how to See page

Before You Begin 2-1 Install the Mounting Base and Wiring Base Assembly 2-1 Install the Module 2-4 Install the Removable Terminal Block 2-6 Remove a Mounting Base 2-6 Wire the Modules 2-7 Communicate with Your Module 2-9

ATTENTION

Preventing Electrostatic Discharge

This equipment is sensitive to electrostatic dischar ge, which can cause internal damage and affect normal operation. Follow these guidelines when you handle this equipment:

• Touch a grounded object to discharge potential static.

• Wear an approved grounding wriststrap.

• Do not touch connectors or pins on component

boards.

• Do not touch circuit components inside the equipment.

• If available, use a static-safe workstation.

• When not in use, store the equipment in

appropriate static-safe packaging.

1 Publication 1734-UM006B-E N-P - August 2005

+ 47 hidden pages

Rockwell Automation 1734-IK User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Important User Information

Summary of Changes

Table of Contents

Preface

Purpose of This Manual

Who Should Use This Manual

Related Products and Documentation

Definitions

About the Modules

What This Chapter Contains

Module Description and Features

Operating Modes

Operating Mode Features

Install the Module

What This Chapter Contains

Before You Begin