Yaskawa SGDB User Manual

AC Servomotors and Driver

SGMG/SGMS/SGMD/SGM/SGMP Servomotors SGDB Servopack

YASKAWA

YA S K A WA

MANUAL NO. TSE-S800-16E

PREFACE

The rapid progress being made in today’s automation and information technologies is resulting in a growing need for even more-advanced motion control for future high-tech equipment. The end result is a need for devices that can provide more-precise and quicker motion at higher speeds. Servo control technology makes this possible. Launched by Yaskawa in 1993, the Σ Series consists of innovative AC Servos that were developed using leading-edge servo control technology.

This manual covers all products in the Σ Series, which feature superior functions and performance. This manual was designed to provide comprehensible information for users who are about to use a servo for the first time as well as for users who already have experience in using servos. This manual enables users to understand what Σ-Series AC Servos are all about and how to design, install, operate, and maintain a servo system. Keep this manual in a convenient location and refer to it whenever necessary in operating and maintaining the servo system.

YASKAWA ELECTRIC CORPORATION

General Precautions

S Some drawings in thismanual are shown with the protective cover or shields removed, in order to

describe the detail with more clarity. Make sure all covers and shields are replaced before operating this product.

S Some drawings in this manual are shown as typical example and may differ from the shipped

product.

S This manual may be modified when necessary because of improvement of the product, modifica-

tion or changes in specifications. Such modification is made as a revision by renewing the manual No.

S To order a copy of this manual, if your copy has been damaged or lost, contact your YASKAWA

representative listed on the last page stating the manual No. on the front cover.

S YASKAWA is not responsible for accidents or damages due to any modification of the product

made by the user since that will void our guarantee.

NOTES FOR SAFE OPERATION

Read this manual thoroughly before installation, operation, maintenance or inspection of the AC Servo

Drives. In this manual, the NOTES FOR SAFE OPERATION are classified as “WARNING” or

“CAUTION”.

WARNING

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious personal inju-

ry.

CAUTION

Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate personal

injury and/or damage to the equipment.

In some instances, items described in

follow these important items.

CAUTION

may also result in a serious accident. In either case,

− iv −

WARNING

(WIRING)

S Grounding must be in accordance with the national code and consistent

with sound local practices.

Failure to observe this warning may lead to electric shock or fire.

(OPERATION)

S Never touch any rotating motor parts during operation.

Failure to observe this warning may result in personal injury.

(INSPECTION AND MAINTENANCE)

S Be sure to turn OFF power before inspection or maintenance.

Otherwise, electric shock may result.

S Never open the terminal cover while power is ON, and never turn ON pow-

er when the terminal cover is open.

Otherwise, electric shock may result.

S After turning OFF power, wait at least five minutes before servicing the

product.

Otherwise, residual electric charges may result in electric shock.

CAUTION

(RECEIVING)

S Use the specified combination of servomotor and SERVOPACK.

Failure to observe this caution may lead to fire or failure.

(INSTALLATION)

S Never use the equipment where it may be exposed to splashes of water,

corrosive or flammable gases, or near flammable materials.

Failure to observe this caution may lead to electric shock or fire.

(WIRING)

S Do not connect three−phase power supply to output terminals

Failure to observe this caution may lead to personal injury or fire.

S Securely tighten screws on the power supply and motor output terminals.

Failure to observe this caution can result in a fire.

and

− v −

CAUTION

(OPERATION)

S To avoid inadvertent accidents, run the servomotor only in test run (with-

out load).

Failure to observe this caution may result in personal injury.

S Before starting operation with a load connected, set up parameters suit-

able for the machine.

Starting operation without setting up parameters may lead to overrun failure.

S Before starting operation with a load connected, make sure emergency-

stop procedures are in place.

Failure to observe this caution may result in personal injury.

S During operation, do not touch the heat sink.

Failure to observe this caution may result in burns.

(INSPECTION AND MAINTENANCE)

S Do not disassemble the servomotor.

Failure to observe this caution may result in electric shock or personal injury.

S Never change wiring while power is ON.

Failure to observe this caution may result in electric shock or personal injury.

− vi −

Manual Contents

This manual providesΣ-Series users with information on the following:

•

An overview of servo systems for first-time users.

•

Checking the product on delivery and basic applications of the servo.

•

Servo applications.

•

Selecting an appropriate servo for your needs and placing an order.

•

Inspection and maintenance.

Manual Structure

All chapters in this manual are classified into one or more of three areas according to their contents: A, B, and C. Refer to the applicable chapters for the information you require.

Chapters explaining how to select a servo: For users who wish to gain a basic understanding of

Series products or who need to select an appropriate servo.

Chapters explaining how to design a servo system: For users who are about to design, install, and operate aΣ-Series Servo Control System.

Chapters explaining maintenance: For users who are going to maintain and troubleshootΣ-Series products.

Chapter

CHAPTER 1 For First-time Users of AC Servos

CHAPTER 2 Basic Uses of Σ-series Products

CHAPTER 3 Applications of Σ-series Products

CHAPTER 4 Using the Digital Operator

CHAPTER 5 Servo Selection and Data Sheets

CHAPTER 6 Inspection, Maintenance, and Troubleshooting

APPENDIXES

Title Page Area

....................... .........

Provides an overview of servos and theΣSeries.

......................... .........

Describes steps to take when product is received, plus basic wiring and application methods.

....................... .........

Describes the effective usage ofΣ-Series features according to application.

.............................. ........

Describes operating procedures forΣ-Series servos, turning features ON and OFF, setting control constants, etc.

........................ ........

Describes selection methods forΣ-Series servos and peripherals and provides servo specifications.

Describes user maintenance and troubleshooting.

Servo Adjustment 539

List of I/O Signals 555

List of Parameters 561

List of Alarm Displays 569

....................................... ........

.................................... ........

177

221

........... ........

499

A, B

B, C

INDEX

.............................................................. 573.........

A, B, C

− vii −

Basic Terms

Unless otherwise specified, the following definitions are used:

Servomotor:

SERVOPACK: An amplifier (Trademark of Yaskawa servo amplifier “Σ-Series SGDB-jAD

Servodrive: A servomotor and an amplifier (SGDB SERVOPACK)

Servo system: A complete servo control system consisting of servodrive, host controller,

Visual Aids

The following aids are used to indicate certain types of information for easier reference.

TERMS

-Series SGMG/SGMD/SGMS/SGM/SGMP servomotor

SERVOPACK”)

and peripheral devices

Indicates references for additional information.

Technical terms placed in bold in the text are briefly explained in a “TERMS” section at the bottom of the page. The following kinds of technical terms are explained: Technical terms that need to be explained to users who are not very familiar with servo systems or electronic devices and technical terms specific toΣSeries Servos that need to be explained in descriptions of functions.

The text indicated by this icon explains the operating procedure using hand-held type digital operator (Type: JUSP-OP02A-1).

JUSP-OP02A-1

NOTE

The text indicated by this icon explains the operating procedure using mount type digital operator (Type: JUSP-OP03A).

AΣ-Series Servodrive alone cannot ensure the functionality and performance of the entire machine control system. It must be combined with an appropriate machine and host controller so that the entire control system works properly. Therefore, carefully read the instruction manuals for the machine to be used before attempting to operate the servodrive.

− viii −

Yaskawa, 1995



All rights reserved. No part of thispublication may be reproduced, stored in aretrieval system, or transmitted, in any form, or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permission of Yaskawa. No patent liability isassumed with respect to the use of the informationcontained herein. Moreover,becauseYaskawa is constantly striving to improve its high-quality products, the information contained in this manual is subject to change without notice. Every precaution has been taken in the preparation of this manual. Nevertheless, Yaskawa assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained in this publication.

− ix −

CHAPTER 1 FOR FIRST-TIME USERS OF AC SERVOS 1...............

1.1 Servo Mechanisms 2.......................................................

1.2 Servo Configuration 5......................................................

1.3 Features of Σ-Series Servos 11................................................

1.3.1 Servomotor Type 11.................................................

1.3.2 Control Type of SERVOPACKs 11......................................

1.3.3 How to Use the SGDB SERVOPACKs 12................................

CHAPTER 2 BASIC USES OF Σ-SERIES PRODUCTS 15.................

2.1 Precautions 16.............................................................

2.1.1 Notes on Use 16....................................................

2.2 Installation 18.............................................................

2.2.1 Checking on Delivery 18..............................................

2.2.2 Servomotors 18.....................................................

2.2.3 SERVOPACKs 22...................................................

2.2.4 Installing the Servomotor 24...........................................

2.2.5 Installing the SERVOPACK 27.........................................

2.3 Connection and Wiring 30....................................................

2.3.1 Connecting to Peripheral Devices 30....................................

2.3.2 Main Circuit Wiring and Power ON Sequence 34..........................

2.3.3 Connection to Host Controller 36.......................................

2.4 Conducting a Test Run 40....................................................

2.4.1 Test Run in Two Steps 40.............................................

2.4.2 Step 1: Conducting a Test Run for Motor without Load 42...................

2.4.3 Step 2: Conducting a Test Run with the Motor Connected to the Machine 46.....

2.4.4 Supplementary Information on Test Run 47...............................

2.4.5 Minimum Parameters Required and Input Signals 49........................

CHAPTER 3 APPLICATIONS OF Σ-SERIES PRODUCTS 51..............

3.1 Setting Parameters According to Machine Characteristics 54.........................

3.1.1 Changing the Direction of Motor Rotation 54..............................

3.1.2 Setting the Overtravel Limit Function 56.................................

3.1.3 Restricting Torque 59................................................

3.2 Setting Parameters According to Host Controller 64................................

3.2.1 Inputting Speed Reference 64..........................................

3.2.2 Inputting Position Reference 68........................................

3.2.3 Using Encoder Outputs 73............................................

3.2.4 Using Contact I/O Signals 77..........................................

3.2.5 Using Electronic Gear 79.............................................

3.2.6 Using Contact Input Speed Control 83...................................

3.2.7 Using Torque Control 87..............................................

3.2.8 Using Torque Feed-forward Function 94.................................

3.2.9 Using Torque Restriction by Analog Voltage Reference 95...................

3.2.10 Using the Reference Pulse Inhibit Function (INHIBIT) 97....................

3.2.11 Using the Reference Pulse Input Filter Selection Function 98.................

3.2.12 Using the Analog Monitor 99..........................................

3.3 Setting Up the Σ SERVOPACK 100.............................................

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CONTENTS

3.3.1 Setting Parameters 100................................................

3.3.2 Setting the Jog Speed 101..............................................

3.3.3 Setting the Number of Encoder Pulses 102.................................

3.3.4 Setting the Motor Type 103.............................................

3.3.5 Adjusting the Encoder Supply Voltage 104.................................

3.4 Setting Stop Mode 105.......................................................

3.4.1 Adjusting Offset 105..................................................

3.4.2 Using Dynamic Brake 106.............................................

3.4.3 Using Zero-Clamp 107................................................

3.4.4 Using Holding Brake 108..............................................

3.5 Running the Motor Smoothly 113...............................................

3.5.1 Using the Soft Start Function 113........................................

3.5.2 Using the Smoothing Function 114.......................................

3.5.3 Adjusting Gain 114...................................................

3.5.4 Adjusting Offset 115..................................................

3.5.5 Setting the Torque Reference Filter Time Constant 115.......................

3.6 Minimizing Positioning Time 117...............................................

3.6.1 Using Autotuning Function 117.........................................

3.6.2 Setting Servo Gain 117................................................

3.6.3 Using Feed-forward Control 119.........................................

3.6.4 Using Proportional Control 119.........................................

3.6.5 Setting Speed Bias 120................................................

3.6.6 Using Mode Switch 121...............................................

3.7 Forming a Protective Sequence 127.............................................

3.7.1 Using Servo Alarm Output and Alarm Code Output 127......................

3.7.2 Using Servo ON Input Signal 130........................................

3.7.3 Using Positioning Complete Signal 131...................................

3.7.4 Using Speed Coincidence Output Signal 134...............................

3.7.5 Using Running Output Signal 136.......................................

3.7.6 Using OL Warning and Alarm Output Signals 138...........................

3.7.7 Using Servo Ready Output Signal 140....................................

3.7.8 Handling of Power Loss 141............................................

3.8 Special Wiring 142..........................................................

3.8.1 Wiring Instructions 142................................................

3.8.2 Wiring for Noise Control 144...........................................

3.8.3 Using More Than One Servo Drive 149...................................

3.8.4 Using Regenerative Resistor Units 151....................................

3.8.5 Using an Absolute Encoder 152.........................................

3.8.6 Extending an Encoder Cable 162........................................

3.8.7 Using SGDB SERVOPACK with High Voltage Line 164......................

3.8.8 Connector Terminal Layouts 166........................................

CHAPTER 4 USING THE DIGITAL OPERATOR 177.....................

4.1 Basic Operations 178.........................................................

4.1.1 Connecting the Digital Operator 178.....................................

4.1.2 Digital Operator Functions 179..........................................

4.1.3 Resetting Servo Alarms 180............................................

− xi −

CONTENTS

4.1.4 Basic Functions and Mode Selection 181..................................

4.1.5 Operation in Status Display Mode 182....................................

4.1.6 Operation in Parameter Setting Mode 186.................................

4.1.7 Operation in Monitor Mode 191.........................................

4.2 Using the Functions 194......................................................

4.2.1 Operation in Alarm Trace-back Mode 194.................................

4.2.2 Operation Using the Digital Operator 197.................................

4.2.3 Autotuning 201......................................................

4.2.4 Reference Offset Automatic Adjustment 207...............................

4.2.5 Reference Offset Manual Adjustment Mode 210............................

4.2.6 Clearing Alarm Trace-back Data 213.....................................

4.2.7 Checking Motor Specifications 215......................................

4.2.8 Checking Software Version 216.........................................

4.2.9 Current Detection Offset Manual Adjustment Mode 217......................

CHAPTER 5 SERVO SELECTION ANDDATA SHEETS 221................

5.1 Selecting a Σ-Series Servo 223.................................................

5.1.1 Selecting a Servomotor 223............................................

5.1.2 Selecting a SERVOPACK 233...........................................

5.1.3 Selecting a Digital Operator 235.........................................

5.2 SGM Servomotor 237........................................................

5.2.1 Ratings and Specifications 237..........................................

5.2.2 Mechanical Characteristics 269..........................................

5.2.3 Option Specifications 272..............................................

5.3 SERVOPACK Ratings and Specifications 282.....................................

5.3.1 Combined Specifications 282...........................................

5.3.2 Ratings and Specifications 285..........................................

5.3.3 Overload Characteristics 288...........................................

5.3.4 Starting Time and Stopping Time 289.....................................

5.3.5 Load Inertia 290.....................................................

5.3.6 Overhanging Loads 291...............................................

5.4 Σ-Series Dimensional Drawings 292.............................................

5.4.1 Servomotor Dimensional Drawings 292...................................

5.4.2 SERVOPACK Dimensional Drawings 400.................................

5.4.3 Digital Operator Dimensional Drawings 412...............................

5.5 Selecting Peripheral Devices 414...............................................

5.5.1 Selecting Peripheral Devices 414........................................

5.5.2 Order List 424.......................................................

5.6 Specifications and Dimensional Drawings of Peripheral Devices 442...................

5.6.1 Cable Specifications and Peripheral Devices 442............................

5.6.2 Motor Cables 446....................................................

5.6.3 Connector 447.......................................................

5.6.4 Brake Power Supply 466...............................................

5.6.5 Encoder Cables 469...................................................

5.6.6 Battery for Absolute Encoder 480........................................

5.6.7 1CN Connector 481...................................................

5.6.8 Connector Terminal Block Converter Unit 483..............................

− xii −

CONTENTS

5.6.9 Cable With 1CN Connector and One End Without Connector 485...............

5.6.10 Circuit Breaker 486...................................................

5.6.11 Noise Filter 486......................................................

5.6.12 Magnetic Contactor 488...............................................

5.6.13 Surge Suppressor 490.................................................

5.6.14 Regenerative Resistor Unit 490..........................................

5.6.15 Variable Resistor for Speed Setting 491...................................

5.6.16 Encoder Signal Converter Unit 492......................................

5.6.17 Cables for Connecting PC and SERVOPACK 494...........................

CHAPTER 6 INSPECTION, MAINTENANCE, AND TROUBLESHOOTING 499.

6.1 Inspection and Maintenance 500................................................

6.1.1 Servomotor 500......................................................

6.1.2 SERVOPACK 501....................................................

6.1.3 Replacing Battery for Absolute Encoder 502...............................

6.2 Troubleshooting 503.........................................................

6.2.1 Troubleshooting Problems with Alarm Display 503..........................

6.2.2 Troubleshooting Problems With No Alarm Display 529.......................

6.2.3 Internal Connection Diagram and Instrument Connection Examples 531.........

A Servo Adjustment 539........................................................

A.1 Σ-Series AC SERVOPACK Gain Adjustment 540..................................

A.1.1 Σ-Series AC SERVOPACKs and Gain Adjustment Methods 540................

A.1.2 Basic Rules for Gain Adjustment 541.....................................

A.2 Adjusting a Speed-control SERVOPACK 542......................................

A.2.1 Adjusting Using Auto-tuning 542........................................

A.2.2 Manual Adjustment 543...............................................

A.3 Adjusting a Position-control SERVOPACK 546....................................

A.3.1 Adjusting Using Auto-tuning 546........................................

A.3.2 Manual Adjustment 547...............................................

A.4 Gain Setting References 551...................................................

A.4.1 Guidelines for Gain Settings According to Load Inertia Ratio 551..............

B List of I/O Signals 555........................................................

C List of Parameters 561........................................................

D List of Alarm Displays 569....................................................

INDEX 573...........................................................

− xiii −

FOR FIRST-TIME USERS OF AC SERVOS

This chapter is intended for first-time users of AC servos. It describes the basic configuration of a servo mechanism and basic technical terms relating to servos. Users who already have experience in using a servo should also take a look at this chapter to understand the features of Σ-Series AC Servos.

1.1 Servo Mechanisms 2.......................

1.2 Servo Configuration 5.....................

1.3 Features of Σ-Series Servos 11................

1.3.1 Servomotor Type 11..................................

1.3.2 Control Type of SERVOPACKs 11.......................

1.3.3 How to Use the SGDB SERVOPACKs 12.................

FOR FIRST-TIME USERS OF AC SERVOS

1.1 Servo Mechanisms

You may be familiar with the following terms:

• Servo

• Servo mechanism

• Servo control system

In fact, these terms are synonymous. They have the following meaning:

A control mechanism that monitors physical quantities such as specified positions.

In short, a servo mechanism is like a servant who does tasks faithfully and quickly according to his master’s instructions. In fact, “servo” originally derives from the word “servant.”

TERMS

Servo mechanism

According to Japanese Industrial Standard (JIS) terminology, a “servo mechanism” is defined as a mechanism that uses the position, direction, or orientation of an object as a process variable to control a system to follow any changes in a target value (set point). More simply, a servo mechanism is a control mechanism that monitors physical quantities such as specified positions. Feedback control is normally performed by a servo mechanism. (Source: JIS B0181)

1 . 1 Servo Mechanisms

Servo system could be defined in more detail as a mechanism that:

• Moves at a specified speed and

• Locates an object in a specified position

To develop such a servo system, an automatic control system involving feedback control must be designed. This automatic control system can be illustrated in the following block diagram:

Configuration of Servo System

Specified position

input

Servo amplifier

Servo motor

Feedback part

Detector

Controlled machine (load)

Machine position

output

This servo system is an automatic control system that detects the machine position (output data), feeds back the data to the input side, compares it with the specified position (input data), and moves the machine by the difference between the compared data.

In other words, the servo system is a system to control the output data to match the specified input data.

If, for example, the specified position changes, the servo system will reflect the changes.

In the above example, input data is defined as a position, but input data can be any physical quantities such as orientation (angle), water pressure, or voltage.

TERMS

Position, speed, force (torque), electric current, and so on are typical controlled values for a servo system.

The main technical terms used in this manual are as follows:

1) Servo mechanism

2) Servo

Normally, servo is synonymous with servo mechanism. However, because “mechanism” is omitted, the meaning becomes somewhat ambiguous. Servo may refer to the entire servo mechanism but may also refer to an integral part of a servo mechanism such as a servomotor or a servo amplifier. This manual also follows this convention in the use of the term “servo”.

Feedback control

A control that returns process variables to the input side and forms a closed loop. It is also called closed-loop control.

FOR FIRST-TIME USERS OF AC SERVOS

3) Servo control system

Servo control system is almost synonymous with servo mechanism but places the focus on system control. In this manual, the term “servo system” is also used as a synonym of servo control system.

Related Terms Meaning

Servomotor

SERVOPACK Trademark of Yaskawa servo amplifier “SGDB

Servo drive A servomotor and amplifier pair. Also called “servo.”

Servo system A closed control system consisting of a host controller,

General servomotors or Yaskawa SGMj servomotors. In some cases, a position detector (encoder) is included in a servomotor.

SERVOPACK.”

servo drive and controlled system to form a servo mechanism.

Host controller

Reference

Amplifier (SERVOPACK)

Servo drive

Servomotor

Servo system

Operate

Controlled system

1.2 Servo Configuration

The following diagram illustrates a servo system in detail:

1.2 Servo Configuration

Host controller

(5)

Position or speed reference

Servo amplifier

Comparator

(Input)

Position or speed feedback

Power amplifier

Detector

(1) Controlled system: Mechanical system for which the position or speed is to be con-

trolled. This includes a drive system that transmits torque from a servomotor.

(4)

Motor drive circuit

Gear

(2)

(3)

servomotor Drive system

(Output)

(1)

Controlled system

Position

Speed

Movable table

Ball screw

(2) Servomotor: A main actuator that moves a controlled system. Two types are

available: AC servomotor and DC servomotor.

(3) Detector: A position or speed detector. Normally, an encoder mounted on

a motor is used as a position detector.

(4) Servo amplifier: An amplifier that processes an error signal to correct the differ-

ence between a reference and feedback data and operates the servomotor accordingly. A servo amplifier consists of a comparator, which processes error signals, and a power amplifier, which operates the servomotor.

(5) Host controller: A device that controls a servo amplifier by specifying a position

or speed as a set point.

FOR FIRST-TIME USERS OF AC SERVOS

Servo components (1) to (5) are outlined below:

(1) Controlled system

In the previous figure, the controlled system is a movable table for which the position or speed is controlled. The movable table is driven by a ball screw and is connected to the servomotor via gears. So, the drive system consists of:

Gears + Ball Screw

This drive system is most commonly used because the power transmission ratio (gear ratio) can be freely set to ensure high positioning accuracy. However, play in the gears must be minimized.

The following drive system is also possible when the controlled system is a movable table:

Coupling + Ball Screw

When the power transmission ratio is 1 : 1, a coupling is useful because it has no play.

Coupling

Rolling-contact guide

Ball screw

Rolling-contact bearing

This drive system is widely used for machining tools.

Housing

Timing Belt + Trapezoidal Screw Thread

A timing belt is a coupling device that allows the power transmission ratio to be set freely and that has no play.

A trapezoidal screw thread does not provide excellent positioning accuracy, so can be

Trapezoidal screw thread

treated as a minor coupling device.

Servomotor

Timing belt

To develop an excellent servo system, it is important to select a rigid drive system that has no play.

Configure the controlled system by using an appropriate drive system for the control purpose.

TERMS

Drive system

Also called a drive mechanism. A drive system connects an actuator (such as a servomotor) to a controlled system and serves as a mechanical control component that transmits torque to the controlled system, orientates the controlled system, and converts motion from rotation to linear motion and vice versa.

(2) Servomotor

(a) DC servomotor and AC servomotor

Servomotors are divided into two types: DC servomotors and AC servomotors.

DC servomotors are driven by direct current (DC). They have a long history. Up until the 1980s, the term “servomotor” used to imply a DC servomotor.

1.2 Servo Configuration

From 1984, AC servomotors were emerging as a result of rapid progress in microprocessor technology. Driven by alternating current (AC), AC servomotors are now widely used because of the following advantages:

• Easy maintenance: No brush

• High speed: No limitation in rectification rate

Note however that servomotors and SERVOPACKs use some parts that are subject to mechanical wear or aging. For preventive maintenance, inspect and replace parts at regular intervals. For details, refer to Chapter 6 Inspection, Maintenance, and Troubleshooting.

(b) AC servomotor

AC servomotors are divided into two types: synchronous type and induction type. The synchronous type is more commonly used.

For a synchronous type servomotor, motor speed is controlled by changing the frequency of alternating current.

A synchronous type servomotor provides strong holding torque when stopped, so this type is ideal when precise positioning is required. Use this type for a servo mechanism for position control.

The following figure illustrates the structure of a synchronous type servomotor:

Rotary disc

Light-emitting element

Position detector (encoder)

Light-receiving element

Armature wire

Lead wire

Housing

Stator core

Magnet

Front cap

Ball bearing

Shaft

Rotor core

Yaskawa SGMj servomotors are of the synchronous type.

FOR FIRST-TIME USERS OF AC SERVOS

A servomotor must have “instantaneous power” so that it can start as soon as a start reference is received. The term “power rating (kW/s)” is used to represent instantaneous power. It refers to the electric power (kW) that a servomotor generates per second. The greater the power rating, the more powerful the servomotor.

(3) Detector

A servo system requires a position or speed detector. It uses an encoder mounted on a servomotor for this purpose. Encoders are divided into the following two types:

(a) Incremental Encoder

An incremental encoder is a pulse generator, which generates a certain number of pulses per revolution (e.g., 2,000 pulses per revolution). If this encoder is connected to the mechanical system and one pulse is defined as a certain length (e.g., 0.001 mm), it can be used as a position detector. However, this encoder does not detect an absolute position and merely outputs a pulse train. Zero point return operation must be performed before positioning. The following figure illustrates the operation principle of a pulse generator:

Phase A pulse train

Phase B pulse train

Fixed slit

Light-receiving element

Rotary slit

Center of revolution

Phase A

Phase B

Phase Z

Rotary disc

Slit

Light-emitting element

(b) Absolute encoder

An absolute encoder is designed to detect an absolute angle of rotation as well as to perform the general functions of an incremental encoder. With an absolute encoder, therefore, it is possible to create a system that does not require zero point return operation at the beginning of each operation.

• Difference between an absolute An absolute

encoder will keep track of the motor shaft position even if system

and incremental encoder:

power is lost and some motion occurs during that period of time. The incremental encoder is incapable of the above.

(4) Servo amplifier

A servo amplifier is required to operate an AC servomotor.

The following figure illustrates the configuration of a servo amplifier:

Servo amplifier

1.2 Servo Configuration

Motor driving AC power

Servomotor

Commercial AC power

Reference input

Comparator

Feedback

Power amplifier

A servo amplifier consists of the following two sections:

(a) Comparator

A comparator consists of a comparison function and a control function. The comparison function compares reference input (position or speed) with a feedback signal and generates a differential signal.

TERMS

The control function amplifies and transforms the differential signal. In other words, it performs proportional (P) control or proportional/integral (PI) control. (It is not important if you do not understand these control terms completely at this point.)

(b) Power amplifier

A power amplifier runs the servomotor at a speed or torque proportional to the output of the comparator. In other words, from the commercial power supply of 50/60 Hz, it generates alternating current with a frequency proportional to the reference speed and runs the servomotor with this current.

Proportional/integral (PI) control

PI control provides more accurate position or speed control than proportional control, which is more commonly used.

FOR FIRST-TIME USERS OF AC SERVOS

(5) Host controller

A host controller controls a servo amplifier by specifying a position or speed as a set point.

For speed reference, a position control loop may be formed in the host controller when a position feedback signal is received. Yaskawa MP920 is a typical host controller.

TERMS

MP920

A machine controller. If combined with a servo amplifier for speed control (maximum 44 axes control), the MP920 can provide position control. The MP920 also provides programmable controller functions.

1.3 Features ofΣ-Series Servos

This section describes the features of Σ-Series servos.

1.3.1 Servomotor Type

1.3 Features ofΣ -Series Servos

Σ-Series SGMj servomotors are synchronous type servomotors and have the following

features:

Rated rotation speed Maximum rotation speed

SGMG

SGMS 3000 r/min

SGMD 2000 r/min

SGM 3000 r/min

SGMP 3000 r/min

1500 r/min 3000 r/min

1000 r/min 2000 r/min

4500 r/min

3000 r/min

4500 r/min

1.3.2 Control Type of SERVOPACKs

Rated output

0.45 to 15 kW (10 models)

0.3 to 6.0 kW (8 models)

1.0 to 5.0 kW (6 models)

2.2 to 4.0 kW (3 models)

0.4 to 0.8 kW (2 models)

0.4 to 1.5 kW (3 models)

SGMG type

SGMP type

SGDB model SERVOPACKs allow the control of speed, position and torque.

• Speed control (analog reference)

Accepts an analog voltage speed reference.

• Speed control (contact reference)

There are 3 internally set speeds. One of these is selected as a reference by a contact.

• Position control (pulse reference)

Accepts a pulse train position reference

• Torque control (analog reference)

Accepts an analog voltage torque reference

SGDB SERVOPACK

FOR FIRST-TIME USERS OF AC SERVOS

1.3.3 How to Use the SGDB SERVOPACKs

J Using SERVOPACK for Speed Control

The most common use of a SERVOPACK for speed control is shown below:

Host controller

Position reference +

Position control loop

Position feedback

(Analog voltage)

Speed reference

Position

Speed

Convert

Position feedback

SERVOPACK (speed control mode)

Power amplifier

Servomotor

Torque (current) feedback

Pulse train

Encoder

As shown in the above figure, a position control loop is formed in the host controller. The host controller compares a position reference with a position feedback signal and sends the processed result to the SERVOPACK as a speed reference.

In this way the host controller can be freed from performing the servo mechanism control. The SERVOPACK undertakes the speed control loop and subsequent control processing.

The Yaskawa programmable machine controller MP920 is used as a typical host controller.

J Using SERVOPACK for Torque Control

SERVOPACK for torque control can be used as shown below:

Host controller

Position monitoring

Position information

Torque reference

(Analog voltage)

Position feedback Encoder

SERVOPACK

(torque control mode)

Power amplifier

Torque (current) feedback

Pulse train

1.3 Features ofΣ -Series Servos

Servomotor

The host controller outputs a torque reference to control the SERVOPACK. It also receives a pulse train (position information) from the SERVOPACK and uses it to monitor the position.

J Using SERVOPACK for Position Control

SERVOPACK for position control can be used as shown below:

Host controller

Position monitoring

Position reference

Position information

Pulse train

Speed/current loop

Position feedback

SERVOPACK (position control mode)

Power amplifier

Servomotor

Pulse train

Encoder

FOR FIRST-TIME USERS OF AC SERVOS

1.3.3 How to Use the SGDB SERVOPACKs cont.

The host controller can send a position reference (pulse train) to the SERVOPACK to perform positioning or interpolation. This type of SERVOPACK contains a position control loop.

Parameters can be used to select either of the following pulse trains:

(1) Code and pulse train

(2) Two-phase pulse train with 90° phase difference

(3) Forward and reverse pulse trains

The host controller receives a pulse train (position information) from the SERVOPACK and uses it to monitor the position.

J Setting Parameters

A Digital Operator can be used to set parameters for a SERVOPACK as follows:

• Setting parameters to enable or disable each function

• Setting parameters required for functions to be used

Set parameters according to the servo system to be set up.

BASIC USES OF Σ-SERIES PRODUCTS

This chapter describes the first things to do whenΣ-Series products are delivered. It also explains the most fundamental ways ofconnecting and operating

-Series products. Both first-time and experienced servo users

this chapter.

2.1 Precautions 16.............................

2.2 Installation 18.............................

must read

2.1.1 Notes on Use 16.....................................

2.2.1 Checking on Delivery 18...............................

2.2.2 Servomotors 18......................................

2.2.3 SERVOPACKs 22....................................

2.2.4 Installing the Servomotor 24............................

2.2.5 Installing the SERVOPACK 27..........................

2.3 Connection and Wiring 30...................

2.3.1 Connecting to Peripheral Devices 30.....................

2.3.2 Main Circuit Wiring and Power ON Sequence 34............

2.3.3 Connection to Host Controller 36........................

2.4 Conducting a Test Run 40...................

2.4.1 Test Run in Two Steps 40..............................

2.4.2 Step 1: Conducting a Test Run for Motor without Load 42....

2.4.3 Step 2: Conducting a Test Run with the Motor Connected to the

Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

2.4.4 Supplementary Information on Test Run 47................

2.4.5 Minimum Parameters Required and Input Signals 49.........

BASIC USES OF Σ-SERIES PRODUCTS

2.1.1 Notes on Use

2.1 Precautions

This section provides notes on using Σ-Series products.

2.1.1 Notes on Use

NOTE Always note the following to ensure safe use.

Use 200VAC power supply

Be sure to use the correct type. Do not plug the servomotor directly into the power frequency supply (Direct connection to the power frequency supply will damage the servomotor.)

200VAC power supply

Always use the SGMj servomotor and SGDB SERVOPACK in pairs.

Check whether the combination of applicable motor series of SERVOPACK and of SGMj ( motor series) is correct or not. Check the setting of parameter Cn-2A (motor selection) and always after changing its combination. The motor may get

Recheck the setting of parameter Cn-2A (motor selection) after changing its combination. Refer to Section 3.3.4.

damaged if the combination is not correct.

Do not change wiring when power is ON.

Direct connection

Damage will result!

Always turn the power OFF before connecting or disconnecting a connector. (Except for Digital Operator (Types: JUSPOP02A-1, JUSP-OP03A))

OFF

(POWER and CHARGE lamp)

Always turn the power OFF before connecting or disconnecting a connector.

Note that residual voltage still remains in the SERVOPACK even after the power is turned OFF.

Even after the power is turned OFF, residual electric charge still remains in the capacitor inside the SERVOPACK. To prevent an electric shock, always wait for the CHARGE lamp to go OFF before starting inspection (if necessary).

CHARGE lamp

2 . 1 Precautions

Always follow the specified installation method.

Provide sufficient clearance

The SERVOPACK generates heat. Install the SERVOPACK so that it can radiate heat freely. Note also that the SERVOPACK must be in an en-

50 mm or more

vironment free from condensation, vibration and shock.

Ambient temperature: 0to55°C

Perform noise reduction and grounding properly.

If the signal line is noisy, vibration or malfunction will result.

D Separate high-voltage cables from low-voltage cables. D Use cables as short as possible. D Ground the SERVOPACK ground terminal with the

resistance 100Ω or less for the servomotor and SERVOPACK.

D Never use a line filter for the power supply in the

motor circuit.

Casing

SERVOPACK

Signal

Conduct a voltage resistance test under the following conditions.

D Voltage: 1500 Vrms AC, one minute D Current limit: 100 mA D Frequency: 50/60 Hz D Voltage application points: Between r, t, R, S, T

terminals and frame ground (connect terminals securely).

line

100 Ω or less

Conduct a voltage resistance test under the conditions given on the left.

10 mm or more

Servomotor

Use a fast-response type ground-fault interrupter.

For a ground-fault interrupter, always use a fastresponse type or one designed for PWM inverters. Do not use a time-delay type.

Fast-response type

Ground-fault interrupter

GOOD POOR

GOOD

For PWM inverter

Do not perform continuous operation under overhanging load.

Continuous operation cannot be performed by rotating the motor from the load and applying regen-

Servomotor

erative braking. Regenerative braking by the SERVOPACK can be applied only for a short period, such as the motor deceleration time.

Do not apply regenerative braking continuously.

The servomotor cannot be operated by turning the power ON and OFF.

Frequently turning the power ON and OFF causes the internal circuit elements to deteriorate. Always start or stop the servomotor by using reference pulses.

Power supply

Time-delay type

SERVOPACK

Do not start or stop by turning power ON and OFF.

BASIC USES OF Σ-SERIES PRODUCTS

2.2.2 Servomotors

2.2 Installation

This section describes how to check Σ-Series products on delivery and how to install them.

2.2.1 Checking on Delivery

When Σ-Series products are delivered, check the following items:

Check Items

Check if the delivered products are the ones you ordered.

Check if the motor shaft rotates smoothly.

Check for damage. Check the overall appearance, and check for damage

Check screws for looseness. Check for looseness by using a screwdriver as

If any of the above items are faulty or incorrect, contact the dealer from which you purchased the products or your nearest local sales representative.

2.2.2 Servomotors

J External Appearance and Nameplate Examples

Remarks

Check the types marked on the nameplates of servomotor and SERVOPACK (see the table below).

If the motor shaft is smoothly turned by hand, it is normal. However, if the motor has brakes, it cannot be turned manually.

or scratches resulting from transportation.

necessary.

Rated output

Servomotor model

Σ-II Series Servomotor

Serial number

Manufacturing date

Rated motor speed

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