Omron CJ1W- ECT21 User manual

Machine Automation Controller
CJ-series
EtherCAT®Slave Unit
EtherCAT Slave Unit
Operation Manual
for NJ-series CPU Unit
W542-E1-01
CJ1W-ECT21

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 permission 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. Neverthe-
less, OMRON 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.
• Sysmac and SYSMAC are trademarks or registered trademarks of OMRON Corporation in Japan and other
countries for OMRON factory automation products.
• Microsoft, Windows, Windows Vista, Excel, and Visual Basic are either registered trademarks or trademarks of
Microsoft Corporation in the USA and other countries.
• EtherCAT®is registered trademark and patented technology, licensed by Beckhoff Automation GmbH, Germany.
• Safety over EtherCAT®is registered trademark and patented technology, licensed by Beckhoff Automation GmbH,
Germany.
• ODVA, CIP, CompoNet, DeviceNet, and EtherNet/IP are trademarks of ODVA.
•The SD and SDHC logos are trademarks of SD-3C, LLC.
Other company names and product names in this document are the trademarks or registered trademarks of their
respective companies.
Trademarks
Copyrights
NOTE
Microsoft product screen shots reprinted with permission from Microsoft Corporation.

1
Introduction
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Introduction
Thank you for purchasing a CJ-series CJ1W-ECT21 EtherCAT Slave Unit.
This manual contains information that is necessary to use the CJ-series CJ1W-ECT21 EtherCAT Slave
Unit for an NJ-series CPU Unit. Please read this manual and make sure you understand the functional-
ity and performance of the NJ-series CPU Unit before you attempt to use it in a control system.
Keep this manual in a safe place where it will be available for reference during operation.
This manual is intended for the following personnel, who must also have knowledge of electrical sys-
tems (an electrical engineer or the equivalent).
• Personnel in charge of introducing FA systems.
• Personnel in charge of designing FA systems.
• Personnel in charge of installing and maintaining FA systems.
• Personnel in charge of managing FA systems and facilities.
For programming, this manual is intended for personnel who understand the programming language
specifications in international standard IEC 61131-3 or Japanese standard JIS B 3503.
This manual covers the following product.
• CJ-series EtherCAT Slave Unit
CJ1W-ECT21
Intended Audience
Applicable Products

CONTENTS
2CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
CONTENTS
Introduction ..............................................................................................................1
Intended Audience....................................................................................................................................... 1
Applicable Products ..................................................................................................................................... 1
CONTENTS................................................................................................................2
Manual Structure ......................................................................................................7
Page Structure and Icons ............................................................................................................................ 7
Special Information ...................................................................................................................................... 8
Precaution on Terminology .......................................................................................................................... 8
Terms and Conditions Agreement ..........................................................................9
Warranty, Limitations of Liability .................................................................................................................. 9
Application Considerations ........................................................................................................................ 10
Disclaimers ................................................................................................................................................ 10
Safety Precautions ................................................................................................. 11
Definition of Precautionary Information...................................................................................................... 11
Symbols..................................................................................................................................................... 11
Warnings.................................................................................................................................................... 12
Cautions..................................................................................................................................................... 14
Precautions for Safe Use.......................................................................................15
Precautions for Correct Use..................................................................................20
Regulations and Standards ...................................................................................22
Conformance to EC Directives .................................................................................................................. 22
Conformance to UL and CSA Standards................................................................................................... 22
Conformance to Shipbuilding Standards ................................................................................................... 23
Conformance to KC Standards .................................................................................................................. 23
Software Licenses and Copyrights ............................................................................................................ 23
Unit Versions ..........................................................................................................24
Unit Versions.............................................................................................................................................. 24
Unit Versions and Sysmac Studio Versions............................................................................................... 25
Related Manuals .....................................................................................................26
Terminology ............................................................................................................27
Revision History .....................................................................................................29
Sections in this Manual .........................................................................................31
Section 1 Features and System Configuration
1-1 Introduction to EtherCAT ...................................................................................................... 1-2
1-1-1 How EtherCAT Works ................................................................................................................. 1-2
1-1-2 Types of EtherCAT Communications .......................................................................................... 1-3
1-2 EtherCAT Slave Unit Features .............................................................................................. 1-5
1-3 System Configuration of CJ-series EtherCAT Slave Unit .................................................. 1-7
1-4 Specifications ........................................................................................................................ 1-9
1-4-1 General Specifications ................................................................................................................ 1-9

3
CONTENTS
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
1-4-2 Functional and Performance Specifications ............................................................................... 1-9
1-4-3 Dimensions............................................................................................................................... 1-10
1-5 Setting Procedures.............................................................................................................. 1-11
Section 2 Nomenclature and Installation
2-1 Nomenclature......................................................................................................................... 2-2
2-1-1 Nomenclature and Functions...................................................................................................... 2-2
2-1-2 Indicators .................................................................................................................................... 2-2
2-1-3 Switch Settings ........................................................................................................................... 2-5
2-2 Installing the EtherCAT Slave Unit....................................................................................... 2-7
2-2-1 System Configuration Precautions ............................................................................................. 2-7
2-2-2 Mounting..................................................................................................................................... 2-7
2-2-3 Handling Precautions.................................................................................................................. 2-8
2-3 EtherCAT Network Wiring..................................................................................................... 2-9
2-3-1 Installation Standards ................................................................................................................. 2-9
2-3-2 Installation Precautions............................................................................................................... 2-9
2-3-3 Preparations for Installation ........................................................................................................ 2-9
2-3-4 Pin Arrangements of Communications Connectors...................................................................2-11
2-3-5 Connecting Communications Cables and Connectors ............................................................. 2-12
2-3-6 Connecting Communication Cables to Units ............................................................................ 2-12
Section 3 Data Exchange with the CPU Unit
3-1 Data Exchange Between the EtherCAT Slave Unit and the CPU Unit............................... 3-2
3-1-1 Data Flow.................................................................................................................................... 3-2
3-1-2 Accessing From the User Program............................................................................................. 3-4
3-2 Device Variables for CJ-series Unit (Status) ....................................................................... 3-9
3-2-1 List of Device Variables for CJ-series Unit.................................................................................. 3-9
3-2-2 Unit Status 1 ............................................................................................................................... 3-9
3-2-3 Unit Status 2 ..............................................................................................................................3-11
3-2-4 Slave Status 1........................................................................................................................... 3-12
3-2-5 Slave Status 2........................................................................................................................... 3-15
3-3 Device Variables for CJ-series Unit (I/O Communication Area Setting)......................... 3-18
3-3-1 List of Device Variables for CJ-series Unit................................................................................3-18
3-3-2 I/O Communication Area Setting Table..................................................................................... 3-19
3-3-3 I/O Communication Area Reference Table ............................................................................... 3-24
3-4 I/O Communication Area Settings ..................................................................................... 3-29
3-4-1 The Unit Edit Special Unit Settings Tab Page........................................................................... 3-29
3-4-2 Setting Procedure with the Sysmac Studio............................................................................... 3-32
Section 4 EtherCAT Communications
4-1 Structure of CAN Application Protocol over EtherCAT (CoE)........................................... 4-2
4-2 EtherCAT Slave Information Files (ESI Files) ..................................................................... 4-3
4-3 Transitions of Communications States ............................................................................... 4-4
4-4 Process Data Objects (PDOs)............................................................................................... 4-5
4-4-1 Introduction................................................................................................................................. 4-5
4-4-2 PDO Mappings ........................................................................................................................... 4-5
4-4-3 Assigning PDOs.......................................................................................................................... 4-7
4-5 Service Data Objects (SDOs)................................................................................................ 4-9
4-5-1 Introduction................................................................................................................................. 4-9
4-5-2 Abort Codes................................................................................................................................ 4-9
4-6 Communications Performance .......................................................................................... 4-10

CONTENTS
4CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
4-6-1 I/O Response Time ................................................................................................................... 4-10
4-6-2 SDO Message Response Time.................................................................................................4-12
Section 5 Troubleshooting
5-1 Error Notification and Check Methods ................................................................................ 5-2
5-1-1 Error Notification Methods........................................................................................................... 5-2
5-1-2 How to Check for Errors.............................................................................................................. 5-3
5-1-3 Procedures to Check Errors........................................................................................................ 5-6
5-2 Troubleshooting with Indicators .......................................................................................... 5-7
5-2-1 Checking for Errors and Troubleshooting with the Indicators ..................................................... 5-7
5-2-2 Corrective Actions When the CPU Unit’s Indicators are Lit or Flashing.................................... 5-14
5-3 Error Log Function of the EtherCAT Slave Unit................................................................ 5-15
5-3-1 Error Log Data........................................................................................................................... 5-15
5-3-2 Error Log Error Codes............................................................................................................... 5-16
5-4 Troubleshooting with Event Logs of the NJ-series Controller........................................ 5-18
5-4-1 Overview of Event Logs ............................................................................................................ 5-18
5-4-2 Event Codes for Errors and Troubleshooting Procedures ........................................................ 5-18
5-5 Troubleshooting with Emergency Messages.................................................................... 5-25
5-5-1 Emergency Message Notification.............................................................................................. 5-25
5-5-2 Emergency Error Codes............................................................................................................ 5-25
5-6 Troubleshooting with AL Status......................................................................................... 5-27
Section 6 Maintenance and Replacement
6-1 Cleaning and Inspection ....................................................................................................... 6-2
6-1-1 Cleaning...................................................................................................................................... 6-2
6-1-2 Inspection.................................................................................................................................... 6-2
6-2 Replacing Faulty Units.......................................................................................................... 6-4
6-2-1 Precautions ................................................................................................................................. 6-4
6-2-2 Settings When Replacing EtherCAT Slave Units ........................................................................ 6-4
Appendices
A-1 Example of Operations for EtherCAT Slave Unit Communications..................................A-2
A-1-1 System Configuration..................................................................................................................A-2
A-1-2 Setting Condition.........................................................................................................................A-3
A-1-3 Flow of the Setting Procedure.....................................................................................................A-4
A-1-4 CJ1W-ECT21 Setting Procedure ................................................................................................A-4
A-1-5 EtherCAT Master Setting Procedure...........................................................................................A-8
A-1-6 Start EtherCAT Communication ................................................................................................A-10
A-2 Programming Example to Detect Valid I/O Process Data ................................................A-11
A-3 Process Data Exchange in PROGRAM Mode....................................................................A-12
A-3-1 Detection Method and Timing Considerations ..........................................................................A-12
A-3-2 Program Example for the EtherCAT Master..............................................................................A-13
A-3-3 Program Example for the EtherCAT Slave Unit ........................................................................A-14
A-4 Differences in Available Functions Depending on the CPU Unit (NJ or CJ Series) ......A-15
A-4-1 Functional Differences ..............................................................................................................A-15
A-4-2 Differences in Accessing from User Program ...........................................................................A-15
A-5 CoE Objects .........................................................................................................................A-22
A-5-1 Object Dictionary Area ..............................................................................................................A-22
A-5-2 Data Type..................................................................................................................................A-22
A-5-3 Format of Objects......................................................................................................................A-22
A-5-4 Communication Objects ............................................................................................................A-23

5
CONTENTS
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
A-5-5 PDO Mapping Objects.............................................................................................................. A-25
A-5-6 Sync Manager Communication Objects ................................................................................... A-28
A-5-7 Device Profile Area................................................................................................................... A-31
A-6 Version Information.............................................................................................................A-33
Index

CONTENTS
6CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)

7
Manual Structure
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Manual Structure
The following page structure is used in this manual.
Page Structure and Icons
4-9
4 Installation and Wiring
NJ-series CPU Unit Hardware User’s Manual (W500)
stinUgnitnuoM3-4
4
stnenopmoCrellortnoCgnitcennoC1-3-4
4-3 Mounting Units
The Units that make up an NJ-series Controller can be connected simply by pressing the Units together
and locking the sliders by moving them toward the back of the Units. The End Cover is connected in the
same way to the Unit on the far right side of the Controller.
1Join the Units so that the connectors fit exactly.
2The yellow sliders at the top and bottom of each Unit lock the Units together. Move the sliders
toward the back of the Units as shown below until they click into place.
Precautions for Correct UsePrecautions for Correct Use
4-3-1 Connecting Controller Components
Connector
Hook Hook holes
Slider
Lock
Release
Move the sliders toward the back
until they lock into place.
Level 1 heading
Level 2 heading
Level 3 heading
Level 2 heading
A step in a procedure
Manual name
Special information
Level 3 heading
Page tab
Gives the current
headings.
Indicates a procedure.
Icons indicate
precautions, additional
information, or reference
information.
Gives the number
of the main section.
This illustration is provided only as a sample. It may not literally appear in this manual.
The sliders on the tops and bottoms of the Power Supply Unit, CPU Unit, I/O Units, Special I/O
Units, and CPU Bus Units must be completely locked (until they click into place) after connecting
the adjacent Unit connectors.

Manual Structure
8CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Special information in this manual is classified as follows:
Precautions for Safe Use
Precautions on what to do and what not to do to ensure safe usage of the product.
Precautions for Correct Use
Precautions on what to do and what not to do to ensure proper operation and performance.
Additional Information
Additional information to read as required.
This information is provided to increase understanding or make operation easier.
Version Information
Information on differences in specifications and functionality for CPU Units and EtherCAT Slave
Units with different unit versions and for different versions of the Sysmac Studio is given.
Note References are provided to more detailed or related information.
• In this manual, “download” refers to transferring data from the Sysmac Studio to the physical Control-
ler and “upload” refers to transferring data from the physical Controller to the Sysmac Studio. For the
Sysmac Studio, synchronization is used to both upload and download data. Here, “synchronize”
means to automatically compare the data for the Sysmac Studio on the computer with the data in the
physical Controller and transfer the data in the direction that is specified by the user.
• In this manual, “CPU Unit” refers to an NJ-series CPU Unit.
Special Information
Precaution on Terminology

9
Terms and Conditions Agreement
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Terms and Conditions Agreement
Exclusive Warranty
Omron’s exclusive warranty is that the Products will be free from defects in materials and workman-
ship for a period of twelve months from the date of sale by Omron (or such other period expressed in
writing by Omron). Omron disclaims all other warranties, express or implied.
Limitations
OMRON MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR IMPLIED, ABOUT
NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OF
THE PRODUCTS. BUYER ACKNOWLEDGES THAT IT ALONE HAS DETERMINED THAT THE
PRODUCTS WILL SUITABLY MEET THE REQUIREMENTS OF THEIR INTENDED USE.
Omron further disclaims all warranties and responsibility of any type for claims or expenses based
on infringement by the Products or otherwise of any intellectual property right.
Buyer Remedy
Omron’s sole obligation hereunder shall be, at Omron’s election, to (i) replace (in the form originally
shipped with Buyer responsible for labor charges for removal or replacement thereof) the non-com-
plying Product, (ii) repair the non-complying Product, or (iii) repay or credit Buyer an amount equal
to the purchase price of the non-complying Product; provided that in no event shall Omron be
responsible for warranty, repair, indemnity or any other claims or expenses regarding the Products
unless Omron’s analysis confirms that the Products were properly handled, stored, installed and
maintained and not subject to contamination, abuse, misuse or inappropriate modification. Return of
any Products by Buyer must be approved in writing by Omron before shipment. Omron Companies
shall not be liable for the suitability or unsuitability or the results from the use of Products in combi-
nation with any electrical or electronic components, circuits, system assemblies or any other materi-
als or substances or environments. Any advice, recommendations or information given orally or in
writing, are not to be construed as an amendment or addition to the above warranty.
See http://www.omron.com/global/ or contact your Omron representative for published information.
OMRON COMPANIES SHALL NOT BE LIABLE FOR SPECIAL, INDIRECT, INCIDENTAL, OR CON-
SEQUENTIAL DAMAGES, LOSS OF PROFITS OR PRODUCTION OR COMMERCIAL LOSS IN ANY
WAY CONNECTED WITH THE PRODUCTS, WHETHER SUCH CLAIM IS BASED IN CONTRACT,
WARRANTY, NEGLIGENCE OR STRICT LIABILITY.
Further, in no event shall liability of Omron Companies exceed the individual price of the Product on
which liability is asserted.
Warranty, Limitations of Liability
Warranties
Limitation on Liability; Etc

Terms and Conditions Agreement
10 CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Omron Companies shall not be responsible for conformity with any standards, codes or regulations
which apply to the combination of the Product in the Buyer’s application or use of the Product. At
Buyer’s request, Omron will provide applicable third party certification documents identifying ratings
and limitations of use which apply to the Product. This information by itself is not sufficient for a com-
plete determination of the suitability of the Product in combination with the end product, machine, sys-
tem, or other application or use. Buyer shall be solely responsible for determining appropriateness of
the particular Product with respect to Buyer’s application, product or system. Buyer shall take applica-
tion responsibility in all cases.
NEVER USE THE PRODUCT FOR AN APPLICATION INVOLVING SERIOUS RISK TO LIFE OR
PROPERTY WITHOUT ENSURING THAT THE SYSTEM AS A WHOLE HAS BEEN DESIGNED TO
ADDRESS THE RISKS, AND THAT THE OMRON PRODUCT(S) IS PROPERLY RATED AND
INSTALLED FOR THE INTENDED USE WITHIN THE OVERALL EQUIPMENT OR SYSTEM.
Omron Companies shall not be responsible for the user’s programming of a programmable Product, or
any consequence thereof.
Data presented in Omron Company websites, catalogs and other materials is provided as a guide for
the user in determining suitability and does not constitute a warranty. It may represent the result of
Omron’s test conditions, and the user must correlate it to actual application requirements. Actual perfor-
mance is subject to the Omron’s Warranty and Limitations of Liability.
Product specifications and accessories may be changed at any time based on improvements and other
reasons. It is our practice to change part numbers when published ratings or features are changed, or
when significant construction changes are made. However, some specifications of the Product may be
changed without any notice. When in doubt, special part numbers may be assigned to fix or establish
key specifications for your application. Please consult with your Omron’s representative at any time to
confirm actual specifications of purchased Product.
Information presented by Omron Companies has been checked and is believed to be accurate; how-
ever, no responsibility is assumed for clerical, typographical or proofreading errors or omissions.
Application Considerations
Suitability of Use
Programmable Products
Disclaimers
Performance Data
Change in Specifications
Errors and Omissions

11
Safety Precautions
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Safety Precautions
The following notation is used in this manual to provide precautions required to ensure safe usage of an
EtherCAT Slave Unit. The safety precautions that are provided are extremely important to safety.
Always read and heed the information provided in all safety precautions.
The following notation is used.
Definition of Precautionary Information
WARNING
Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury. Additionally, there may be
severe property damage.
Caution Indicates a potentially hazardous situation which, if not avoided,
may result in minor or moderate injury, or property damage.
Symbols
The circle and slash symbol indicates operations that you must not do.
The specific operation is shown in the circle and explained in text.
This example indicates prohibiting disassembly.
The triangle symbol indicates precautions (including warnings).
The specific operation is shown in the triangle and explained in text.
This example indicates a precaution for electric shock.
The triangle symbol indicates precautions (including warnings).
The specific operation is shown in the triangle and explained in text.
This example indicates a general precaution.
The filled circle symbol indicates operations that you must do.
The specific operation is shown in the circle and explained in text.
This example shows a general precaution for something that you must do.
The triangle symbol indicates precautions (including warnings).
The specific operation is shown in the triangle and explained in text.
This example indicates the precaution for high temperatures.

Safety Precautions
12 CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Warnings
WARNING
During Power Supply
Do not touch any of the terminals or terminal blocks while the power is being
supplied. Doing so may result in electric shock.
Do not attempt to take any Unit apart. In particular, high-voltage parts are
present in the Power Supply Unit while power is supplied or immediately
after power is turned OFF. Touching any of these parts may result in electric
shock. There are sharp parts inside the Unit that may cause injury.
Fail-safe Measures
Unintended outputs may occur when an error occurs in variable memory or
in memory used for CJ-series Units. As a countermeasure for such prob-
lems, external safety measures must be provided to ensure safe operation of
the system. Emergency stop circuits, interlock circuits, limit circuits, and sim-
ilar safety measures must be provided in external control circuits.
Provide measures in the communications system and user program to
ensure safety in the overall system even if errors or malfunctions occur in
data link communications or remote I/O communications.
Provide safety measures in external circuits to ensure safety in the system if
an abnormality occurs due to malfunction of the CPU Unit, other Units, or
slaves or due to other external factors affecting operation.
Not doing so may result in serious accidents due to incorrect operation.
The CJ-series Controller continues normal operation for a certain period of
time when a momentary power interruption occurs. This means that the
CJ-series Controller may receive incorrect signals from external devices that
are also affected by the power interruption. Accordingly, take suitable
actions, such as external fail-safe measures and interlock conditions, to
monitor the power supply voltage of the external device as required.
You must take fail-safe measures to ensure safety in the event of incorrect,
missing, or abnormal signals caused by broken signal lines, momentary
power interruptions, or other causes. Not doing so may result in serious acci-
dents due to incorrect operation.
The Controller outputs may remain ON or OFF due to deposition or burning
of the output relays or destruction of the output transistors.
As a countermeasure for such problems, external safety measures must be
provided to ensure safe operation of the system.

13
Safety Precautions
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
The CPU Unit refreshes I/O even when the program is stopped (i.e., even in
PROGRAM mode). Confirm safety thoroughly in advance before changing
the status of any part of memory allocated to I/O Units, Special I/O Units, or
CPU Bus Units. Any changes to the data allocated to any Unit may result in
unexpected operation of the loads connected to the Unit. Any of the following
operation may result in changes to memory status.
• Transferring I/O memory data to the CPU Unit from a programming device.
• Changing present values in memory from a programming device.
• Force-setting/-resetting bits from a programming device.
• Transferring I/O memory files from a Memory Card or EM file memory to
the CPU Unit.
• Transferring I/O memory from a host computer or from another Controller
on a network.
The CPU Unit will turn OFF all outputs from Basic Output Units in the follow-
ing cases. The slaves will operate according to the settings in the slaves.
• If an error occurs in the power supply
• If the power supply connection becomes faulty
• If a CPU watchdog timer error or CPU reset occurs
• If a major fault level Controller error occurs
• While the CPU Unit is on standby until RUN mode is entered after the
power is turned ON
External safety measures must be provided to ensure safe operation of the
system in such cases.
Downloading
Always confirm safety at the destination before you transfer a user program,
configuration data, setup data, device variables, or values in memory used
for CJ-series Units from the Sysmac Studio. The devices or machines may
perform unexpected operation regardless of the operating mode of the CPU
Unit.
Actual Operation
Check the user program, data, and parameter settings for proper execution
before you use them for actual operation.
Voltage and Current Inputs
Make sure that the voltages and currents that are input to the Units and
slaves are within the specified ranges.
Inputting voltages or currents that are outside of the specified ranges may
cause accidents or fire.

Safety Precautions
14 CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Cautions
Caution
Application
Do not touch any Unit when power is being supplied or immediately after the
power supply is turned OFF. Doing so may result in burn injury.
Wiring
Be sure that all terminal screws and cable connector screws are tightened to
the torque specified in the relevant manuals. The loose screws may result in
fire or malfunction.
Online Editing
Execute online editing only after confirming that no adverse effects will be
caused by deviations in the timing of I/O. If you perform online editing, the
task execution time may exceed the task period, I/O may not be refreshed
with external devices, input signals may not be read, and output timing may
change.

15
Precautions for Safe Use
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Precautions for Safe Use
When performing online editing with the combination of a CPU Unit with a unit version of 1.04 or later
and Sysmac Studio version 1.05 or higher, the CPU Unit saves a program updated by the online editing
to built-in non-volatile memory. Sysmac Studio shows a message that it is in a backup operation. Do not
turn OFF the power supply to the Controller while this message is displayed. If the power supply to the
Controller is turned OFF, a Controller error will occur when power is reapplied.
• Do not attempt to disassemble, repair, or modify any Units. Doing so may result in malfunction or fire.
• Do not drop any Unit or subject it to abnormal vibration or shock. Doing so may result in Unit malfunc-
tion or burning.
• When transporting the Unit, use special packing boxes and protect it from being exposed to exces-
sive vibration or impacts during transportation.
• After connecting Power Supply Units, CPU Units, I/O Units, Special I/O Units, or CPU Bus Units
together, secure the Units by sliding the sliders at the top and bottom of the Units until they click into
place. Correct operation may not be possible if the Units are not securely properly.
• Always connect to a ground of 100 Ωor less when installing the Units. A ground of 100 Ωor less
must be installed when shorting the GR and LG terminals on the Power Supply Unit.
• Install the Unit properly. Improper installation of the Unit may result in malfunction.
• Follow the instructions in this manual to correctly perform wiring.
Double-check all wiring and switch settings before turning ON the power supply.
• Do not pull on the cables or bend the cables beyond their natural limit.
Do not place heavy objects on top of the cables or other wiring lines. Doing so may break the cables.
• Mount terminal blocks and connectors only after checking the mounting location carefully.
Be sure that the terminal blocks, expansion cables, and other items with locking devices are properly
locked into place.
• Before you connect a computer to the CPU Unit, disconnect the power supply plug of the computer
from the AC outlet. Also, if the computer has an FG terminal, make the connections so that the FG
terminal has the same electrical potential as the FG (GR) terminal on the Power Supply Unit. A differ-
ence in electric potential between the computer and Controller may cause failure or malfunction.
• Use crimp terminals for wiring. Do not connect bare stranded wires directly to terminals. Incorrect wir-
ing may result in burning.
Online Editing
Disassembly and Dropping
Transporting
Mounting
Installation
Wiring

Precautions for Safe Use
16 CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
• Do not exceed the rated supply capacity of the Power Supply Units in the NJ-series Controller. The
rated supply capacities are given in the NJ-series CPU Unit Hardware User’s Manual (Cat. No.
W500).
If the capacity is exceeded, operation may stop, malfunctions may occur, or data may not be backed
up normally for power interruptions.
Use NJ-series Power Supply Units for both the NJ-series CPU Rack and Expansion Racks.
Operation is not possible if a CJ-series Power Supply Unit is used with an NJ-series CPU Unit or an
NJ-series Power Supply Unit is used with a CJ-series CPU Unit.
• Surge current occurs when the power supply is turned ON. When selecting fuses or breakers for
external circuits, consider the above precaution and allow sufficient margin in shut-off performance.
Refer to the relevant manuals for surge current specifications. Refer to the NJ-series CPU Unit Hard-
ware User’s Manual (Cat. No. W500) for surge current specifications.
• If the full dielectric strength voltage is applied or turned OFF using the switch on the tester, the gener-
ated impulse voltage may damage the Power Supply Unit. Use the adjustment on the tester to grad-
ually increase and decrease the voltage.
• Apply the voltage between the Power Supply Unit's L1 or L2 terminal and the GR terminal when test-
ing insulation and dielectric strength.
• Do not supply AC power from an inverter or other device with a square-wave output. Internal temper-
ature rise may result in smoking or burning. Always input a sinusoidal wave with the frequency that is
given in the NJ-series CPU Unit Hardware User’s Manual (Cat. No. W500). Refer to the NJ-series
CPU Unit Hardware User’s Manual (Cat. No. W500).
• Apply the voltage between the Power Supply Unit's L1 or L2 terminal and the GR terminal when test-
ing insulation and dielectric strength.
• Install external breakers and take other safety measures against short-circuiting in external wiring.
• It takes up to approximately 10 to 20 s to enter RUN mode after the power is turned ON. During that
time, outputs will be the values specified in the Unit or slave. Use the RUN output on the Power Sup-
ply Unit, for example, to implement fail-safe circuits so that external devices do not operate incor-
rectly.
• Configure the external circuits so that the power supply to the control system turns ON only after the
power supply to the Controller has turned ON. If the power supply to the Controller is turned ON after
the control power supply, temporary errors may result in incorrect control system signals because the
output terminals on Output Units may momentarily turn ON when power supply is turned ON to the
Controller.
• If you transfer data from a backup file on an SD Memory Card to the Controller when the power sup-
ply is turned ON, properly select the data groups to transfer. If the data for an unintended data group
is transferred to the Controller, it may cause the equipment to operate unpredictably.
• Double-check all wiring before turning ON the power supply. Incorrect wiring may result in burning.
• Check the user program, data, and parameter settings for proper execution before you use them for
actual operation.
• Confirm that the I/O Communication Area Setting Table and I/O Reference Area Setting Table set-
tings are correct. Incorrect system settings can cause unexpected behavior.
Power Supply Design
Turning ON the Power Supply
Actual Operation

17
Precautions for Safe Use
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
• Never turn OFF the power supply to the Controller when the BUSY indicator is flashing. While the
BUSY indicator is lit, the user program and settings in the CPU Unit are being backed up in the
built-in non-volatile memory. This data will not be backed up correctly if the power supply is turned
OFF. Also, a major fault level Controller error will occur the next time you start operation, and opera-
tion will stop.
• Do not turn OFF the power supply or remove the SD Memory Card while SD Memory Card access is
in progress (i.e., while the SD BUSY indicator flashes). Data may become corrupted, and the Control-
ler will not operate correctly if it uses corrupted data. To remove the SD Memory Card from the CPU
Unit while the power supply is ON, press the SD Memory Card power supply switch and wait for the
SD BUSY indicator to turn OFF before you remove the SD Memory Card.
• Do not disconnect the cable or turn OFF the power supply to the Controller when downloading data
or the user program from Support Software.
• Always turn OFF the power supply to the Controller before you attempt any of the following.
a) Mounting or removing I/O Units or the CPU Unit
b) Assembling the Units
c) Setting DIP switches or rotary switches
d) Connecting cables or wiring the system
e) Connecting or disconnecting the connectors
• Do not touch the terminals on the Power Supply Unit immediately after turning OFF the power supply.
Residual voltage may cause electrical shock.
• Never turn OFF the power supply to the Controller until RUN mode is entered after the power is
turned ON. If the power supply is turned OFF, a Battery-backup Memory Check Error may occur at
next time you start operation. If a Battery-backup Memory Check Error occurs, the variables retained
are set to their initial values and the Holding, DM and EM Areas in memory used for CJ-series Units
are cleared to all zeros. If you want to resume the operation, reload the correct data for the variables
retained and CJ-series Unit memory, as required.
• Confirm that no adverse effect will occur in the system before you attempt any of the following.
a) Changing the operating mode of the CPU Unit (including changing the setting of the Startup
Mode)
b) Changing the user program or settings
c) Changing set values or present values
d) Forced refreshing
• If two different function modules are used together, such as when you use CJ-series Basic Units and
EtherCAT slaves, take suitable measures in the user program and external controls to ensure that
safety is maintained in the controlled system if one of the function modules stops. The relevant out-
puts will behave according to the slave or Unit specifications if a partial fault level error occurs in one
of the function modules.
• Always confirm safety at the connected equipment before you reset Controller errors for a CJ-series
Special Unit. When a Controller error is reset, the Unit where the Controller error with an event level
of observation or higher will be restarted.
Before you reset all errors, confirm that no Controller errors with an event level of observation or
higher have occurred for the CJ-series Special Unit. Observation level events do not appear on the
Controller Error Tab Page, so it is possible that you may restart the CJ-series Special Unit without
intending to do so.
You can check the status of the _CJB_UnitErrSta[0,0] to _CJB_UnitErrSta[3,9] error status variables
on a Watch Tab Page to see if an observation level Controller error has occurred.
• After you change any slave or Unit settings, carefully check the safety of the controlled system before
you restart the Unit.
Turning OFF the Power Supply
Operation

Precautions for Safe Use
18 CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
• The user program and initial values for the variables are stored in non-volatile memory in the CPU
Unit. The present values of variables with the Retain attribute and the values of the Holding, DM, and
EM Areas in the memory used for CJ-series Units are backed up by a Battery. If the Battery is not
connected or the Battery is exhausted, the CPU Unit detects a Battery-backup Memory Check Error.
If that error is detected, variables with a Retain attribute are set to their initial values and the Holding,
DM, and EM Areas in memory used for CJ-series Units are cleared to all zeros. Perform thorough
verifications and provide sufficient measures to ensure that the devices perform safe operation for
the initial values of the variables with Retain attributes and the resulting operation.
• Forced refreshing ignores the results of user program execution and refreshes I/O with the specified
values. If forced refreshing is used for inputs for which I/O refreshing is not supported, the inputs will
first take the specified values, but they will then be overwritten by the user program. This operation
differs from the force-set/reset functionality of the CJ-series PLCs.
• You cannot upload or download information for forced refreshing with the Sysmac Studio. After down-
loading data that contains forced refreshing, change to RUN mode and then use the Sysmac Studio
to perform the operation for forced refreshing.
Depending on the difference in the forced status, the control system may operate unexpectedly.
• Do not specify the same address for the AT specification for more than one variable.
Doing so would allow the same entity to be accessed with different variable names, which would
make the user program more difficult to understand and possibly cause programming mistakes.
When you use data link communications, check the error information that is given in _ErrSta (Controller
Error Status) to make sure that no error has occurred in the source device. Create a user program that
uses reception data only when there is no error in the source device. If there is an error in the source
device, the data for the data link may contain incorrect values.
• Make sure that the communications distance, number of nodes connected, and method of connec-
tion for EtherCAT are within specifications.
• Do not connect EtherCAT communications to EtherNet/IP, a standard in-house LAN, or other net-
works. An overload may cause the network to fail or malfunction.
• The maximum length between nodes is 100 m. However, some cables are specified for less than 100
m. Generally speaking, if the conductors are twisted wire rather than solid wire, transmission perfor-
mance will be lower, and reliable communications may not be possible at 100 m. Confirm details with
the cable manufacturer.
• After you transfer the user program, the CPU Unit is restarted and communications with the Ether-
CAT slaves are cut off. During that period, the slave outputs behave according to the slave settings.
The time that communications are cut off depends on the EtherCAT network configuration. Before
you transfer the user program, confirm that the system will not be adversely affected.
• If noise occurs or an EtherCAT slave is disconnected from the network, any current communications
frames may be lost. If frames are lost, slave I/O data is not communicated, and unintended operation
may occur. The slave outputs will behave according to the slave specifications. Confirm that the sys-
tem will not be adversely affected before you disconnect a slave.
• When an EtherCAT slave is disconnected or disabled, communications will stop and control of the
outputs will be lost not only for the disconnected slave, but for all slaves connected after it. Confirm
that the system will not be adversely affected before you disconnect or disable a slave.
Battery Backup
Debugging
General Communications
EtherCAT Communications