Omron SYSMAC C500-NC222-E User manual

OPERATION MANUAL
Two-axis Position Control Unit
(NC221 Mode)
SYSMAC
C500-NC222-E
Cat. No. W138-E1-03

C500-NC222-E
Two-axis Position Control Unit
(NC221 Mode)
Operation Manual
Revised June 2003

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Notice:
OMRON products are manufactured for use according to proper procedures by a qualified operator
and only for the purposes described in this manual.
The following conventions are used to indicate and classify warnings in this manual. Always heed the
information provided with them.
DANGER Indicates information that, if not heeded, could result in loss of life or serious inju-
ry.
Caution Indicates information that, if not heeded, could result in minor injury or damage
to the product.
OMRON Product References
All OMRON products are capitalized in this manual. The word “Unit” is also capitalized when it refers
to an OMRON product, regardless of whether or not it appears in the proper name of the product.
The abbreviation “Ch,” which appears in some displays and on some OMRON products, means
“word” and is abbreviated “Wd” in documentation.
Visual Aids
The following headings appear in the left column of the manual to help you locate different types of
information.
Indicates information of particular interest for efficient and convenient opera-
tion of the product.
Indicates lists of one sort or another, such as procedures, precautions, etc.
OMRON, 1990
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any
form, or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permis-
sion of OMRON.
No patent liability is assumed with respect to the use of the information contained herein. Moreover, because OMRON 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, OMRON assumes no
responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the informa-
tion contained in this publication.
Note
1, 2, 3...

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TABLE OF CONTENTS
vii
PRECAUTIONS xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Intended Audience xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 General Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Safety Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operating Environment Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Application Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 1
Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1 Features 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2 Basic Operating Principles 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 Operational Flow 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 System Configuration 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5 Control System Configuration 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6 Control System Principles 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-7 Precautions When Using C500-NC222-E in NC221 Mode 10. . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2
Wiring 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1 M/D Connector 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2 EXT-IN Connector 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3 Faulty Wiring Diagnostic Function 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4 Motor Driver Connection Examples 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-5 Wiring Precautions 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3
Data Configuration 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1 Overview 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 Data Allocations 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3 Setting Parameters 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-4 Setting Positioning Actions 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-5 Setting Dwell Times 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-6 Setting Acceleration and Deceleration Times 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-7 Setting Speeds 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-8 Initial Data 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4
Data Communication with PC 57. . . . . . . . . . . . . . . . . . . . .
4-1 Compatible Models and Words 58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 PC Programs 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5
Operating Status 65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1 Flag Transitions and Types 66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2 Status Word Allocations 68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3 Status Word Details 70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4 Flag Changes 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE OF CONTENTS
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SECTION 6
Commands 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-1 Command Format 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-2 Command Descriptions 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-3 Command Processing 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-4 Interpolation 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-5 Relation between SRT and Positioning Actions 95. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 7
Establishing the Origin 97. . . . . . . . . . . . . . . . . . . . . . . . . . .
7-1 CCHG 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-2 Origin Search (XORG, YORG, IORG) 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7-3 Origin Compensation 100. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 8
Programming Examples 101. . . . . . . . . . . . . . . . . . . . . . . . . .
8-1 Data Word Allocations 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-2 Data Transmission Program 105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-3 Basic Program Examples 108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-4 Application Program Examples 115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 9
External Display, Switches, and Indicators 129. . . . . . . . . . .
9-1 External Display 130. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-2 Display Descriptions 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9-3 Switches and Indicators 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 10
Error Processing 135. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-1 Procedure 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-2 Basic Troubleshooting 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-3 System Errors 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-4 Command/Data Errors 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10-5 Communications Errors 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix
A.Position Control Unit Specifications 137. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B. External Display Specifications 141. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C. Error Code List 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.Position Action Data Coding Sheets 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary 151. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision History 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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About this Manual:
The C500-NC222-E Position Control Unit in NC221 mode is a Special I/O Unit for SYSMAC C500,
C1000H, and C2000H Programmable Controllers (PCs) that support WRIT (87) and READ (88). This
Position Control Unit (PCU) in NC221 mode is designed to control positioning through voltage outputs
to a motor driver according to PC programming and external control inputs.
This manual covers the specifications and procedures necessary for installation and operation. It also
describes data layouts and examples for communication between the PLC and NC222 Module in
NC221 mode. Before attempting to operate the Position Control Unit, be sure to thoroughly familiarize
yourself with the information contained in this manual. During operation, refer also to your PC Opera-
tion Manual for programming and system details. If you wish to enter data manually via the Teaching
Box, please use this manual for wiring and setup only. Refer to manual number W145 for data entry
and operations.
Section 1 contains information on the features of the Position Control Unit, system configuration, and
an overview of control system principles.
Section 2 contains wiring diagrams and other information necessary for installation and connection of
the Position Control Unit.
Section 3 provides the minimum information necessary to assemble and test a servomotor driver
system using both axes.
Sections 4, 5, and 6 provide information essential for operation, including data configuration, the set-
ting of parameters and positioning actions, communication between the Position Control Unit and the
PC, and the use of status flags.
Section 7 provides a description of command format. It also contains tables of system, servo control,
and data processing commands, including the functions and usage examples for each.
Section 8 shows how to establish the origin, which must be done to establish a reference point be-
fore executing positioning actions.
Section 9 provides a variety of programming examples to illustrate the principles covered in this man-
ual.
Sections 10 and 11 cover external displays and error processing.
The appendices contain specifications, an error code list, and data coding sheets.
WARNING Failure to read and understand the information provided in this manual may result in
personal injury or death, damage to the product, or product failure. Please read each
section in its entirety and be sure you understand the information provided in the section
and related sections before attempting any of the procedures or operations given.
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PRECAUTIONS
This section provides general precautions for using the Programmable Controller (PC) and related devices.
The information contained in this section is important for the safe and reliable application of the PC. You must read
this section and understand the information contained before attempting to set up or operate a PC system.
1 Intended Audience xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 General Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Safety Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operating Environment Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Application Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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xii
1 Intended Audience
This manual is intended for the following personnel, who must also have knowl-
edge of electrical systems (an electrical engineer or the equivalent).
•Personnel in charge of installing FA systems.
•Personnel in charge of designing FA systems.
•Personnel in charge of managing FA systems and facilities.
2 General Precautions
The user must operate the product according to the performance specifications
described in the operation manuals.
Before using the product under conditions which are not described in the manual
or applying the product to nuclear control systems, railroad systems, aviation
systems, vehicles, combustion systems, medical equipment, amusement
machines, safety equipment, and other systems, machines, and equipment that
may have a serious influence on lives and property if used improperly, consult
your OMRON representative.
Make sure that the ratings and performance characteristics of the product are
sufficient for the systems, machines, and equipment, and be sure to provide the
systems, machines, and equipment with double safety mechanisms.
This manual provides information for programming and operating OMRON PCs.
Be sure to read this manual before attempting to use the software and keep this
manual close at hand for reference during operation.
WARNING It is extreme important that a PC and all PC Units be used for the specified
purpose and under the specified conditions, especially in applications that can
directly or indirectly affect human life. You must consult with your OMRON
representative before applying a PC System to the abovementioned
applications.
3 Safety Precautions
WARNING Never attempt to disassemble any Units while power is being supplied. Doing so
may result in serious electrical shock or electrocution.
WARNING Never touch any of the terminals while power is being supplied. Doing so may
result in serious electrical shock or electrocution.
4 Operating Environment Precautions
Do not operate the control system in the following places.
•Where the PC is exposed to direct sunlight.
•Where the ambient temperature is below 0°C or over 55°C.
•Where the PC may be affected by condensation due to radical temperature
changes.
•Where the ambient humidity is below 10% or over 90%.
•Where there is any corrosive or inflammable gas.
•Where there is excessive dust, saline air, or metal powder.
•Where the PC is affected by vibration or shock.
•Where any water, oil, or chemical may splash on the PC.
Operating Environment Precautions 4

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xiii
Caution The operating environment of the PC System can have a large effect on the lon-
gevity and reliability of the system. Improper operating environments can lead to
malfunction, failure, and other unforeseeable problems with the PC System. Be
sure that the operating environment is within the specified conditions at installa-
tion and remains within the specified conditions during the life of the system.
5 Application Precautions
Observe the following precautions when using the PC.
WARNING Failure to abide by the following precautions could lead to serious or possibly
fatal injury. Always heed these precautions.
•Always ground the system to 100 Ωor less when installing the system to pro-
tect against electrical shock.
•Always turn off the power supply to the PC before attempting any of the follow-
ing. Performing any of the following with the power supply turned on may lead
to electrical shock:
•Mounting or removing any Units (e.g., I/O Units, CPU Unit, etc.) or memory
cassettes.
•Assembling any devices or racks.
•Connecting or disconnecting any cables or wiring.
Caution Failure to abide by the following precautions could lead to faulty operation or the
PC or the system or could damage the PC or PC Units. Always heed these pre-
cautions.
•Use the Units only with the power supplies and voltages specified in the opera-
tion manuals. Other power supplies and voltages may damage the Units.
•Take measures to stabilize the power supply to conform to the rated supply if it
is not stable.
•Provide circuit breakers and other safety measures to provide protection
against shorts in external wiring.
•Do not apply voltages exceeding the rated input voltage to Input Units. The
Input Units may be destroyed.
•Do not apply voltages exceeding the maximum switching capacity to Output
Units. The Output Units may be destroyed.
•Always disconnect the LG terminal when performing withstand voltage tests.
•Install all Units according to instructions in the operation manuals. Improper
installation may cause faulty operation.
•Provide proper shielding when installing in the following locations:
•Locations subject to static electricity or other sources of noise.
•Locations subject to strong electromagnetic fields.
•Locations subject to possible exposure to radiation.
•Locations near to power supply lines.
•Be sure to tighten Backplane screws, terminal screws, and cable connector
screws securely.
•Do not attempt to take any Units apart, to repair any Units, or to modify any
Units in any way.
Caution The following precautions are necessary to ensure the general safety of the sys-
tem. Always heed these precautions.
•Provide double safety mechanisms to handle incorrect signals that can be
generated by broken signal lines or momentary power interruptions.
•Provide external interlock circuits, limit circuits, and other safety circuits in
addition to any provided within the PC to ensure safety.
Application Precautions 5

1
SECTION 1
Introduction
The C500-NC222-E Position Control Unit (PCU) in NC221 mode is a Special I/O Unit that receives positioning commands
from the Programmable Controller (PC) and outputs control voltages to two servomotor drivers. Since it outputs control volt-
ages rather than pulses, it can be directly connected to any of a variety of servomotor drivers. You can use it with the C500,
C1000H, or C2000H PC.
Each of the two servomotor drivers controls a servomotor which rotates one of the two positioning axes. The Position Control
Unit can control the axes independently or simultaneously. Both straight-line and circular arc interpolation are also possible.
This section describes the basic features, components, and operation of the Position Control Unit in NC221 mode, as well as
the basic configuration and principles of positioning control systems. Reading this section first will give you a familiarity with
the essential terminology used in this manual and an understanding of the fundamentals necessary for successful operation.
1-1 Features 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2 Basic Operating Principles 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 Operational Flow 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 System Configuration 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5 Control System Configuration 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6 Control System Principles 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-7 Precautions When Using C500-NC222-E in NC221 Mode 10. . . . . . . . . . . . . . . . . . . . . . . . .

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1-1 Features
A control output voltage range from –10 V to +10 V enables connection to
various servomotor drivers.
The Position Control Unit is designed to control two axes. Data configuration
consisting of parameters, speeds, dwell times, acceleration and deceleration
times, and positioning actions permits straight-line interpolation or circular arc
interpolation by simultaneous dual-axis operation. Each motor axis may also
be operated independently.
Troubleshooting is facilitated by error code transmission from the Position
Control Unit to the PC as well as by error code display on the External Dis-
play.
The data capacity in the Position Control Unit provides 300 positioning ac-
tions per axis, 19 parameters per axis, 100 speeds, 10 dwell times per axis,
and 10 acceleration and deceleration times per axis. All data is stored in the
built-in EEPROM for battery-free and maintenance-free backup. Data is read
into the RAM from the EEPROM when power is turned ON.
Connecting the Teaching Box permits position inputs, position input reading,
teaching inputs, and operation monitoring.
All data and command communications between the Programmable Control-
ler and Position Control Unit use PC Intelligent I/O Read and Write instruc-
tions permitting high-speed processing.
The C500-NC222-E Position Control Unit in NC221 mode can be used with a
C500, C1000H, or C2000H PC. The C500-CPU11-EV1 CPU can be used
with the C500, CVM1, CV500, CV1000, or CV2000 PC. Any C1000H and
C2000H CPU may be used.
1-2 Basic Operating Principles
The basic operation of the C500-NC222-E Position Control Unit is fairly sim-
ple. It controls a servomotor driver in accordance with data stored in its
memory. This data includes parameters, speeds, positions, and other infor-
mation necessary for effective control. Before the Position Control Unit can
be operated, you must first input the essential data. This is generally done
via the Teaching Box.
The way in which the Position Control Unit makes use of this data is deter-
mined by the program in the PC. The program does not control all of the Po-
sition Control Unit’s operations directly, but rather, transfers commands to the
Position Control Unit for execution. The commands control such functions as
the starting and stopping of positioning, returning to the origin, and so on.
Thus, while the Position Control Unit functions as an integral part of your
overall control system, it also exercises a good deal of autonomy. This capa-
bility is essential to the concept of distributed control, whereby control of
each portion of an automated system is located near the devices actually
being controlled.
Applicable Motor Drivers
Number of Control Axes
and Controlling Capacity
Error Diagnostics
Large Data Capacity with
Backup
Teaching Box
High-speed
Communications Between
PC and PCU
Applicable CPUs
Basic Operating Principles Section 1-2

3
The fundamental unit of positioning is the positioning action. A particular po-
sitioning action moves the workpiece along the axis in a direction, at a speed,
and to a position determined by the data which has been set specifically for
the positioning action. The positioning action begins when the start command
is transferred by the PC program (XSRT, YSRT, or ISRT, depending on
whether you want to position along the X axis, the Y axis, or both simulta-
neously). Before beginning execution of positioning actions, it is necessary to
define the origin as a reference point by, for example, executing origin search
(XORG, YORG, or IORG). The origin is simply the point which is designated
as 0 at any given time. Positioning actions are described in detail in 3-4 Set-
ting Positioning Actions, using commands to start positioning actions is de-
scribed in 6-5 SRT (Start) Commands and Positioning Actions, and using
commands with the origin is described in Section 7 Establishing the Origin.
Basic Operating Principles Section 1-2

4
1-3 Operational Flow
Positioning operations generally involve the following steps.
NO (no error)
Wiring between
servomotor drivers and
Position Control Unit
START
Wiring external
inputs
Wiring between motors
and servomotor drivers
Power ON
Operation via
PC program?
Write PC
program.
Run PC
program.
Confirm motor
operation.
Change to
actual data.
Change PC program
to actual program.
Run PC
program.
Confirm motor
operation.
Error LED
lights?
Read
error code.
Correct
error.
Error
cleared?
Connect
Teaching Box.
Operate
Teaching Box.
Confirm motor
operation.
Change to
actual data.
Operate
Teaching Box.
Yes
No
No (no error)
No
Yes
Trial
operation
Mount motors
to mechanical
system.
Final
wiring
Create PC
program application.
Yes (error)
Confirm actual
operation.
Refer to
appropriate
operation
manuals.
Error LED
lights?
Read error code.
Correct error.
Error cleared?
NO
YES
Operation
(positioning actions)
YES (error)
Original, CW limit CCW limit,
emergency stop, external interrupt, etc.
Refer to Section 2 Wiring.
Wire according to operation
manuals for motors and
servomotor drivers.
Refer to 2-4 Motor Driver Connection
Examples
Initial data is set. Servolock enabled.
Refer to 3-8 Initial Data.
Refer to the
operation
manual for
the Teaching
Box.
Refer to
Section 8
Programming
Examples.
Setup Debugging
Operational Flow Section 1-3

5
1-4 System Configuration
The following configuration illustrates example connections for a working sys-
tem.
Note The Position Control Unit cannot be used if mounted to a Slave Rack.
Control inputs
PC
C500-TU002-E
Teaching Box
Feedback inputs, control voltages
24-VDC
power supply External interrupt
switch
Control
panel
External input
switches
External input switches
AC Servomotor
AC Servomotor Driver
AC Servomotor Driver
24-VDC
power supply
C500-NC222-E
AC Servomotor
Emergency
stop switch
0
System Configuration Section 1-4

6
1-5 Control System Configuration
The following block diagram shows a control system for a servomotor driver.
The Position Control Unit is arranged in a semiclosed-loop system.
C500-NC222-E PCU Control voltage
output
+10 V
Servomotor driver
Servomotor
Position
Tachogenerator
Position feedback Rotary encoder
CW limit Origin CCW limit
Emergency stop External interrupt
Teaching Box
C500-TU002-E
Memory
D/A convertor
(16 bits)
Counter
Extrnal input
interface
Teaching Box–
External Display
interface
M/D (Motor Driver)
connector
Peripheral
connector
MPU
PC
PC bus interface
EXT–IN connector
–10 V
Speed feedback
Control Inputs
1-6 Control System Principles
Control systems can be quite simple or relatively complex. The most basic is
an open-loop system, in which a particular operation is carried out, according
to programmed instructions, but in which no feedback is provided for auto-
matic adjustments.
In a closed-loop system, PC controls an external process without human in-
tervention. The servomotor provides direct feedback so that actual values (of
positions, speeds, and so on) are continuously adjusted to bring them more
closely in line with target values. The digital feedback signals are commonly
transmitted to a digital-to-analog converter to complete the feedback loop,
thereby permitting automated control of the process.
The C500-NC222-E Position Control Unit is designed for use in a semi-
closed-loop system. A semiclosed-loop system is similar to a closed-loop
system, except that feedback is provided by a tachogenerator and a rotary
encoder rather than directly by the servomotor. This system, which also in-
Open-loop Systems
Closed-loop Systems
Semiclosed-Loop Systems
Control System Principles Section 1-6

7
cludes an error counter, a D/A converter, and a servomotor driver, detects
machine movements by rotation of the motor in relation to the target, com-
putes the error between the target value and actual movement, and zeroes
the error through feedback.
Servo-
motor
driver
Tachogenerator
Rotary encoder
Speed feedback
Position feedback (feedback pulses)
Speed
voltage
D/A
converter
Desired position Error
counter
Servomotor
(pulse string)
1. First, the error counter receives a target position in units of encoder
pulses. The error counter transfers its contents to the D/A convertor
which converts the contents to analog speed voltages for the servomo-
tor driver.
Servomotor Driver
Speed Characteristics
Rotational speed
+N (rpm)
–V +V Speed voltage
–N
Position Control Unit
Action
Control System Principles Section 1-6

8
2. The motor rotates at a speed corresponding to the speed voltage. The
rotary encoder connected to the motor axis rotates in sync with the mo-
tor, generates feedback pulses, and subtracts error counter contents.
Desired
position
(pulses)
Error
counter
count
(pulses)
Speed
voltage
Time set
Positioning end
Time
Time
Time
3. Consequently, the encoder rotation is equivalent to the target position,
and the motor stops rotating when the error counter count and the
speed voltage becomes zero (stopping motor rotation).
4. While the motor is stopped, the rotary encoder constantly maintains the
stopped position through correction. If the motor axis moves slightly, the
error counter receives a feedback pulse from the rotary encoder and a
rotation voltage is emitted in the reverse direction, causing the motor to
rotate toward its original position. This operation is called servolock or
servoclamp.
Control System Principles Section 1-6

9
5. In order to execute positioning by the semiclosed-loop method with ac-
celeration and deceleration, target positions are set consecutively in the
error counter for processing, thus enabling smooth acceleration and de-
celeration.
Desired
position
(pulses)
Error
counter
count
(pulses)
Speed
voltage
Time
Time
Time
6. The target position becomes the count for the error counter and controls
the motor by conversion to a speed voltage for the servomotor driver.
Thus, the position equals the total count of target positions (shaded area
in the figure), and the speed will depend on the desired position per unit
time.
Consider the following positioning system where millimeter is selected as the
unit:
N
V
P
L
M
Rotary encoder
Servomotor
Reduction gear
Moving object
Feed-screw pitch
Where:
N = rotary encoder resolution (pulse/rev)
M = reduction ratio
V =speed of moving object (mm/s)
P = feed-screw pitch (mm/rev)
L = distance moved (mm)
Simplified Positioning
System Design
Control System Principles Section 1-6