Mitsubishi Electric Melsec QJ71LP21 User manual

Q Corresponding MELSECNET/H
Network System
Reference Manual (PLC to PLC network)
-QJ71LP21
-QJ71LP21-25
-QJ71LP21S-25
-QJ71LP21G
-QJ71LP21GE
-QJ71BR11
-QJ71NT11B

A - 1 A - 1
• SAFETY PRECAUTIONS •
(Read these precautions before using this product.)
Before using this product, please read this manual and the relevant manuals carefully and pay full
attention to safety to handle the product correctly.
The instructions given in this manual are concerned with this product. For the safety instructions of the
programmable controller system, please read the CPU module user's manual.
In this manual, the safety precautions are classified into to levels: " WARNING" and " CAUTION".
Under some circumstances, failure to observe the precautions given under " CAUTION" may lead to
serious consequences.
Observe the precautions of both levels because they are important for personal and system safety.
Make sure that the end users read this manual and then keep the manual in a safe place for future
reference.
[Design Precautions]
WARNING
• For operating status of each communication failure, refer to this manual. Incorrect output or
malfunction due to a communication failure may result in an accident.
• If a coaxial cable is disconnected, this may destabilize the line, and a network communication
error may occur in multiple stations. Provide an interlock circuit in the sequence program so that
the system will operate safely even if the above error occurs. Failure to do so may result in an
accident due to incorrect output or malfunction.
• When changing data of the running programmable controller from a peripheral connected to the
CPU module or from a personal computer connected to an intelligent function module or special
function module, configure an interlock circuit in the sequence program to ensure that the entire
system will always operate safely.
For program modification and operating status change, read relevant manuals carefully and
ensure the safety before operation.
Especially, in the case of a control from an external device to a remote programmable controller,
immediate action cannot be taken for a problem on the programmable controller due to a
communication failure.
To prevent this, configure an interlock circuit in the sequence program, and determine corrective
actions to be taken between the external device and CPU module in case of a communication
failure.
! !
!
!

A - 2 A - 2
[Design Precautions]
CAUTION
• Do not install the control lines or communication cables together with the main circuit lines or
power cables.
Keep a distance of 100mm or more between them.
Failure to do so may result in malfunction due to noise.
[Installation Precautions]
CAUTION
• Use the programmable controller in the operating an environment that meets the general
specifications given in the user's manual for the CPU module used.
Failure to do so may result in electric shock, fire, malfunction, or damage to or deterioration of
the product.
• To mount the module, while pressing the module mounting lever located in the lower part of
module, fully insert the module fixing projection(s) into the hole(s) in the base unit press the
module until it snaps into place.
Incorrect mounting may cause malfunction, failure or drop of the module.
When using the programmable controller in an environment of frequent vibrations, fix the
module a screw.
Tighten the screw within the specified torque range.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or
malfunction.
• Shut off the external power supply for the system in all phases before mounting or removing the
module. Failure to do so may result in damage to the product.
• Do not directly touch any conductive part of the module.
Doing so can cause malfunction or failure of the module.
!
!

A - 3 A - 3
[Wiring Precautions]
WARNING
• Shut off the external power supply (all phases) used in the system before installation and wiring.
Failure to do so may result in electric shock or damage to the product.
CAUTION
• Individually ground the FG terminal of the programmable controller with a ground resistance of
100 or less.
Failure to do so may result in electric shock malfunction.
• Check the rated voltage and terminal layout before wiring to the terminal block for the external
power supply, and connect the cable correctly.
Connecting a cable to power supply with a different voltage rating or incorrect wiring may cause
a fire or failure.
• Tighten the terminal screw within the specified torque range.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or
malfunction.
• Properly solder the parts of a soldering-type coaxial cable connector. Incomplete soldering may
result in malfunction.
• Crimp the parts of a crimping-type coaxial cable connector with proper force at a proper position.
Failure to do so may cause drop of the cable or malfunction.
• Prevent foreign matter such as dust or wire chips from entering the module.
Such foreign matter can cause a fire, failure, or malfunction.
• A protective film is attached to the top of the module to prevent foreign matter, such as wire
chips, from entering the module during wiring.
Do not remove this film during wiring.
Remove it for heat dissipation before system operation.
• Place the cables in a duct or clamp them.
Failure to do so may cause damage of the module or the cables due to accidental pull or
unintentional shifting of the cables, or malfunctions due to poor contact of the cable.
• Do not install the control lines or communication cables together with the main circuit lines or
power cables.
Keep a distance of 100mm or more between them.
Failure to do so may result in malfunction due to noise.
• When disconnecting the communication and power cables from the module, do not pull the
cable by the cable part. Loosen the screws of connector before disconnecting the cable. When
disconnecting a cable connected to a terminal block, loosen the screws on the terminal block
first before removing the cable.
Failure to do so may result in damage to the module or cable or malfunction due to poor contact.
!
!

A - 4 A - 4
[Setup and Maintenance Precautions]
CAUTION
• Before performing online operations (especially, program modification, forced output, and
operation status change) for the running CPU module in other station from GX Developer via
MELSECNET/H, read relevant manuals carefully and ensure the safety.
• Do not disassemble or modify the module. Doing so may cause failure, malfunction, injury, or a
fire.
• Use any radio communication device such as a cellular phone or a PHS (Personal Handy-phone
System) more than 25cm (9.85 inches) away in all directions from the programmable controller.
Failure to do so may cause malfunction.
• Shut off the external power supply for the system in all phases before mounting or removing the
module. Failure to do so may cause the module to fail or malfunction.
• Do not touch any terminals while power is on. Doing so will cause electric shock.
• Shut external power supply for the system before cleaning the module or retightening the
terminal screws or module fixing screws.
Failure to do so may cause the module to fail or malfunction.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or
malfunction.
• After the firs use of the product, do not mount/remove the module to/from the base unit more
than 50 times (IEC 61131-2 compliant) respectively.
Exceeding the limit of 50 times may cause malfunction.
• Before handling the module, touch a grounded metal object to discharge the static electricity
from the human body.
Failure to do so may cause the module to fail or malfunction.
[Disposal Precautions]
CAUTION
• When disposing of this product, treat it as industrial waste.
!
!

A - 5 A - 5
• CONDITIONS OF USE FOR THE PRODUCT •
(1) Mitsubishi programmable controller ("the PRODUCT") shall be used in conditions;
i) where any problem, fault or failure occurring in the PRODUCT, if any, shall not lead to any major
or serious accident; and
ii) where the backup and fail-safe function are systematically or automatically provided outside of
the PRODUCT for the case of any problem, fault or failure occurring in the PRODUCT.
(2) The PRODUCT has been designed and manufactured for the purpose of being used in general
industries.
MITSUBISHI SHALL HAVE NO RESPONSIBILITY OR LIABILITY (INCLUDING, BUT NOT
LIMITED TO ANY AND ALL RESPONSIBILITY OR LIABILITY BASED ON CONTRACT,
WARRANTY, TORT, PRODUCT LIABILITY) FOR ANY INJURY OR DEATH TO PERSONS OR
LOSS OR DAMAGE TO PROPERTY CAUSED BY the PRODUCT THAT ARE OPERATED OR
USED IN APPLICATION NOT INTENDED OR EXCLUDED BY INSTRUCTIONS, PRECAUTIONS,
OR WARNING CONTAINED IN MITSUBISHI'S USER, INSTRUCTION AND/OR SAFETY
MANUALS, TECHNICAL BULLETINS AND GUIDELINES FOR the PRODUCT.
("Prohibited Application")
Prohibited Applications include, but not limited to, the use of the PRODUCT in;
 Nuclear Power Plants and any other power plants operated by Power companies, and/or any other
cases in which the public could be affected if any problem or fault occurs in the PRODUCT.
 Railway companies or Public service purposes, and/or any other cases in which establishment of
a special quality assurance system is required by the Purchaser or End User.
 Aircraft or Aerospace, Medical applications, Train equipment, transport equipment such as
Elevator and Escalator, Incineration and Fuel devices, Vehicles, Manned transportation,
Equipment for Recreation and Amusement, and Safety devices, handling of Nuclear or
Hazardous Materials or Chemicals, Mining and Drilling, and/or other applications where there is a
significant risk of injury to the public or property.
Notwithstanding the above, restrictions Mitsubishi may in its sole discretion, authorize use of the
PRODUCT in one or more of the Prohibited Applications, provided that the usage of the PRODUCT
is limited only for the specific applications agreed to by Mitsubishi and provided further that no
special quality assurance or fail-safe, redundant or other safety features which exceed the general
specifications of the PRODUCTs are required. For details, please contact the Mitsubishi
representative in your region.

A - 6 A - 6
REVISIONS
The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Dec., 1999 SH(NA)-080049-A First printing
Oct., 2000 SH(NA)-080049-B Correction
Safety Precautions, Contents, About Manuals, About the Generic
Terms and Abbreviations, Chapter 1, Section 1.1, 1.2, Chapter 2,
Section 2.1.3, 2.1.4, 2.2.2, 3.1.1, 3.1.2, 3.2, 3.2.1, 3.2.2, 3.3, 3.3.1,
3.3.2, 3.3.3, 4.1, 4.2, 4.3.1, 4.3.2, 4.5, 4.5.1, 4.5.2, 4.5.3, 4.6.1, 4.6.2,
4.7, 4.7.1, 4.7.2, 4.8, 4.8.1, 4.8.2, 4.8.3, 4.8.4, Chapter 5, Section 5.1,
5.2, 5.2.3, 5.2.4, 5.2.5, 5.2.6, 5.5, 5.7, 5.7.1, 5.10, 6.1.2, 6.2, 6.2.1,
6.2.2, 6.2.3, 6.3, Chapter 7, Section 7.2, 7.3.1, 7.4, 7.4.1, 7.4.3, 7.4.5,
7.5, 7.5.3, 7.5.4, 7.5.5, 7.6, 7.7, 7.8, Chapter 8, Section 8.1, 8.1.1, 8.2,
8.2.1, 8.2.2, 8.2.3, 8.2.4, 8.2.5, 8.3, 8.4, Appendix 2.2, 3, 4
Addition
Product Configuration, Section 2.4, 2.5, 2.6, Appendix 1.2, Index
Deletion
Section 2.4
May, 2001 SH(NA)-080049-C Module addition
QJ71LP21G, QJ71LP21GE
Correction
Safety Precautions, Contents, About the Generic Terms and
Abbreviations, Section 1.1, 1.2, 2.4, 2.13, 2.1.4, 2.2, 2.2.1, 2.3, 3.1.1,
3.1.3, 3.2, 3.2.2, 3.3.2, 3.3.3, 3.3.4, 4.3.2, 4.4.2, 4.5.1, 4.5.2, 4.5.3,
4.6.2, 4.7.1, 4.7.2, Chapter 5, Section 5.1, 5.2.5, 5.2.6, 5.4, 5.6, 5.7.1,
5.7.2, 5.8, 5.9, 6.1.2, 6.2.1, 6.3, Chapter 7, Section 7.2, 7.3, 7.3.1,
7.4.1, 7.4.2, 7.4.5, 7.5, 7.9, 8.1.1, 8.1.4, 8.3, Appendix 2.1
Addition
Section 2.5
Section number changed
Section 2.5 2.6, 2.6 2.7
June, 2002 SH(NA)-080049-D Module addition
QJ71LP21S-25
Correction
Safety Precautions, Contents, About Manuals, Product Configuration,
Section 1.1, 1.2, 2.2, 3.1.1, 3.2.2, 3.3.2, 4.2, 5.2.1, 5.6, 6.2.1, 6.2.2,
Chapter 7, Section 7.3, 7.3.2, 7.4.5, 8.3, Appendix 3, 4, Index
Apr., 2003 SH(NA)-080049-E Correction
Safety Precautions, Contents, About Manuals, Section 1.2, 2.1.3, 2.2.2,
2.5, 3.1.1, 3.2.1, 3.2.2, 3.3.1, 3.3.3, Chapter 5, Section 5.2.1, 5.7, 5.7.1,
5.7.2, 5.8, 5.9, 6.1.2, 6.2, 6.4, 7.1, 7.4.2, 7.4.3, 7.4.4, 7.4.5, 7.5, 7.5.4,
7.8, 7.9, 8.1, 8.2, 8.2.1, 8.2.5, 8.3

A - 7 A - 7
The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Jun., 2004 SH(NA)-080049-F · The contents of function version D were added.
· The entire manual was reviewed.
Oct., 2004 SH(NA)-080049-G Mode addition
MELSECNET/H Extended Mode
Correction
Safety Precautions, Product Configuration, Section 1.1, 1.2, 2.1.2, 2.2,
2.2.2, 2.2.3, 3.1.1, 3.2.1, 3.3.2, 4.2, 4.3.3, 4.6.1, 4.6.2, 4.8.1, Chapter 5,
Section 5.1, 5.4, 6.2.2, 6.2.3, 7.4.5, 7.6, 7.10.2, 8.1, 8.1.1, 8.1.2, 8.1.3,
8.2, 8.2.1, 8.2.7, 8.3, Appendix 1.1, 1.2, 3, 4, 5, INDEX
Addition
Section 8.2.5, 8.2.9, 8.2.10
Section number changed
Section 8.2.5 8.2.6, 8.2.6 8.2.7, 8.2.7 8.2.8
Oct., 2005 SH(NA)-080049-H Correction
Safety Precautions, Conformation to the EMC Directive and Low
Voltage Instruction, Section 1.1, 1.2, 2.1.2, 2.2, 2.2.1, 2.2.3, 3.1.3,
3.3.2, 4.2, 4.6.1, 4.7.1, 4.7.2, 4.8.1, Chapter 5, Section 5.1, 5.4,
Chapter 6, 7, Section 7.3.1, 7.7, 7.10.2, 8.1.2, 8.1.3, 8.2, 8.2.5, 8.3,
Appendix 1.1, 1.2, 3, 4, 5
Apr., 2006 SH(NA)-080049-I Correction
Section 2.3, 3.1.2, 4.2, 6.3, 7.4.5, Appendix 4
Oct., 2007 SH(NA)-080049-J Change of a term
"PLC" was changed to "programmable controller".
Correction
About the Generic Terms and Abbreviations, 1.2, 2.1.3, 2.1.4, 2.2, 2.3,
3.2.1, 3.3.2, 3.3.3, 4.2, 4.5.1, 4.5.2, 4.5.3, 4.6.1, 4.7.1, 4.7.2, Chapter 5,
5.1, 5.6, 5.7, 5.7.1, 5.7.2, 6.1.1, 6.2.2, 6.3, 6.4, 7.2, 7.4.5, 7.5.5, 7.10.2,
8.1, 8.2.1, 8.2.4, 8.3, Appendix 3, 4, 5
Addition
DEFINITIONS OF TERMINOLOGY
Jul., 2008 SH(NA)-080049-K Correction
SAFETY PRECAUTIONS, Compliance with the EMC and Low Voltage
Directives, About the Generic Terms and Abbreviations, DEFINITIONS
OF TERMINOLOGY, Chapter 1, Section 2.1, 2.2, 3.1.1, 3.1.3, 3.2,
3.3.2 to 3.3.4, 4.2, 4.3.4, 4.6.2, 4.7.1, 4.7.2, Chapter 5, Section 5.1, 5.4,
5.6 to 5.9, 6.1.1, 6.3, Chapter 7, Section 7.2, 7.3, 7.4.1, 7.4.2, 7.4.5,
7.5, 7.5.5, 7.7 to 7.9, 7.10.2, 7.10.5, 7.10.7, 8.1, 8.3, Appendix 1.1, 2.1,
3, 4

A - 8 A - 8
The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Jan., 2009 SH(NA)-080049-L Mode addition
QJ71NT11B
Correction
SAFETY PRECAUTIONS, COMPLIANCE WITH THE EMC AND LOW
VOLTAGE DIRECTIVES, GENERIC TERMS AND ABBREVIATIONS,
PACKING LIST, Section 1.1 to 1.3, 2.1.1, 2.1.2, 2.1.4, 2.2, 2.2.3,
3.1.1 to 3.1.3, 3.2.2, 3.3.2, 3.3.3, 4.1 to 4.3, 4.5, 4.5.1 to 4.5.3, 4.7.1,
4.7.2, 4.8, 4.8.2, Chapter 5, Section 5.1, 5.2.5, 5.4, 5.7.1, 6.1.1, 6.4,
7.1 to 7.3, 7.4.1, 7.4.2, 7.4.5, 7.5.5, 7.9, 7.10.2, 8.2, 8.2.1 to 8.2.4, 8.3,
8.4, Appendix 1.1, 1.2, 3, 4, INDEX
Addition
Section 3.1.4, 3.1.5, 4.2.1 to 4.2.3, 4.6.3, 4.6.4, 5.2.6, 8.2.6,
Appendix 5
Section number changed
Section 4.3.3 4.3.2, 4.3.4 4.3.3, 4.3.5 4.3.4, 5.2.6 5.2.7,
8.2.6 8.2.7, 8.2.7 8.2.8, 8.2.8 8.2.9, 8.2.9 8.2.10,
8.2.10 8.2.11, Appendix 5 6
Aug., 2009 SH(NA)-080049-M Correction
Section 1.3, 2.2, 2.3, Chapter 8, Appendix 1.2
Addition
Section 8.3.1
Section number changed
Section 8.3(4) 8.3.2
Sep., 2010 SH(NA)-080049-N Correction
GENERIC TERMS AND ABBREVIATIONS, Section 1.3, 2.2.1, 2.3,
4.2.1, 4.2.2, 4.2.3, 4.3.1, 5.8, 6.4, 7.4.5, 7.5.6, 8.2.4, 8.2.8, 8.2.10,
8.3.2, Appendix 4, 6
Addition
CONDITIONS OF USE FOR THE PRODUCT
May, 2012 SH(NA)-080049-O Correction
SAFETY PRECAUTIONS, COMPLIANCE WITH THE EMC AND LOW
VOLTAGE DIRECTIVES, GENERIC TERMS AND ABBREVIATIONS,
Section 2.2, 2.3, 3.1.3, 3.1.4, 3.2.2, 3.3.1, 4.2.1, 4.6.2, 5.7, 6.1.1, 6.3,
7.4.5, 7.10.2, 8.3.2, Appendix 3, 6

A - 9 A - 9
The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Sep., 2016 SH(NA)-080049-P Correction
GENERIC TERMS AND ABBREVIATIONS, DEFINITIONS OF
TERMINOLOGY, Section 1.3, 2.1.4, 2.2, 2.3, 3.1.1, 3.1.2, 3.1.4, 3.3.1,
3.3.2, 4.2.1, 4.2.3, 4.3.1, 4.6.3, Chapter 5, Section 5.1, 5.4, 6.1.1, 6.3,
6.4, 7.4.2, 7.4.5, 8.2, Appendix 1.1, 2.1, 3, 4, 5, 6
Nov., 2017 SH(NA)-080049-Q Correction
Section 7.7
Sep., 2019 SH(NA)-080049-R Correction
GENERIC TERMS AND ABBREVIATIONS, Section 2.2, 8.1.2,
Appendix 1.2
Addition
Section 8.2.4
Section number changed
Section 8.2.4 to Section 8.2.11 Section 8.2.5 to Section 8.2.12
Japanese Manual Version SH-080026-X
This manual confers no industrial property rights or any rights of any other kind, nor does it confer any patent
licenses. Mitsubishi Electric Corporation cannot be held responsible for any problems involving industrial property
rights which may occur as a result of using the contents noted in this manual.
© 1999 MITSUBISHI ELECTRIC CORPORATION

A - 10 A - 10
INTRODUCTION
Thank you for purchasing the Mitsubishi Electric MELSEC-Q series programmable controller.
Before using the product, please read this manual carefully to develop full familiarity with the functions and
performance of the Q series programmable controller to handle the product correctly.
Please forward a copy of this manual to the end user.
CONTENTS
SAFETY PRECAUTIONS ............................................................................................................................ A- 1
CONDITIONS OF USE FOR THE PRODUCT ........................................................................................... A- 5
REVISIONS .................................................................................................................................................. A- 6
CONTENTS .................................................................................................................................................. A- 10
MANUALS .................................................................................................................................................... A- 15
COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES ............................................................. A- 15
GENERIC TERMS AND ABBREVIATIONS ............................................................................................... A- 16
DEFINITIONS OF TERMINOLOGY ............................................................................................................ A- 18
PACKING LIST ............................................................................................................................................ A- 19
1 OVERVIEW 1- 1 to 1-14
1.1 Overview ................................................................................................................................................ 1- 1
1.2 Features ................................................................................................................................................. 1- 4
1.3 Symbols Used in This Manual ............................................................................................................... 1- 14
2 SYSTEM CONFIGURATION 2- 1 to 2-19
2.1 MELSECNET/H Network Configurations .............................................................................................. 2- 1
2.1.1 Single network system .................................................................................................................... 2- 1
2.1.2 Redundant system (Redundant CPU) ............................................................................................ 2- 3
2.1.3 Simple dual-structured system (High Performance model QCPU and Process CPU) ................. 2- 4
2.1.4 Multiple network system (High Performance model QCPU, Process CPU, Redundant CPU,
and Universal model QCPU) .......................................................................................................... 2- 5
2.2 Applicable Systems ................................................................................................................................ 2- 6
2.2.1 Precautions when using link dedicated instructions ....................................................................... 2- 9
2.2.2 Precautions when using network modules in the multiple CPU system ....................................... 2- 11
2.2.3 List of functions for each CPU module ........................................................................................... 2- 17
2.3 Checking Serial Number and Function Version .................................................................................... 2- 18
3 SPECIFICATIONS 3- 1 to 3-52
3.1 Performance Specifications ................................................................................................................... 3- 1
3.1.1 Performance specifications ............................................................................................................. 3- 1
3.1.2 Optical fiber cable specifications..................................................................................................... 3- 5
3.1.3 Coaxial cable specifications ............................................................................................................ 3- 6
3.1.4 Shielded twisted pair cable specifications ...................................................................................... 3- 11
3.1.5 CC-Link Ver. 1.10-compatible cable specifications ........................................................................ 3- 13
3.2 Function Specifications .......................................................................................................................... 3- 14
3.2.1 Cyclic transmission function (periodical communication) .............................................................. 3- 15
3.2.2 RAS function .................................................................................................................................... 3- 18
3.3 Specifications of the Link Data Sending/Receiving Processing Time .................................................. 3- 29
3.3.1 Link data sending/receiving processing ......................................................................................... 3- 29
3.3.2 How to calculate the transmission delay time ................................................................................ 3- 33

A - 11 A - 11
3.3.3 Reducing the link refresh time ........................................................................................................ 3- 47
3.3.4 Reduction of the link scan time ....................................................................................................... 3- 52
3.3.5 Control station shift time .................................................................................................................. 3- 52
4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION 4- 1 to 4-45
4.1 Procedures Before Starting the Operation ............................................................................................ 4- 1
4.2 Part Names and Settings ....................................................................................................................... 4- 2
4.2.1 QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G, QJ71LP21GE .................................... 4- 2
4.2.2 QJ71BR11 ....................................................................................................................................... 4- 5
4.2.3 QJ71NT11B ..................................................................................................................................... 4- 7
4.3 Loading and Installation ......................................................................................................................... 4- 8
4.3.1 Handling precautions ...................................................................................................................... 4- 8
4.3.2 Installing and uninstalling the module ............................................................................................. 4- 10
4.3.3 Stopping the CPU module (unintentional output prevention) ........................................................ 4- 11
4.3.4 Checking the input power supply voltage ....................................................................................... 4- 11
4.4 Powering On .......................................................................................................................................... 4- 11
4.4.1 Checking the on status of the POWER LED of the power supply module .................................... 4- 11
4.4.2 Checking the on status of the RUN LED of the network module .................................................. 4- 11
4.5 Standalone Check of the Network Module (Offline Tests) ................................................................... 4- 12
4.5.1 Self-loopback test ............................................................................................................................ 4- 13
4.5.2 Internal self-loopback test ............................................................................................................... 4- 15
4.5.3 Hardware test .................................................................................................................................. 4- 17
4.6 Cable Connection .................................................................................................................................. 4- 19
4.6.1 Optical loop system ......................................................................................................................... 4- 19
4.6.2 Coaxial bus system ......................................................................................................................... 4- 22
4.6.3 Twisted bus system (when using a shielded twisted pair cable) ................................................... 4- 27
4.6.4 Twisted bus system (when using CC-Link Ver. 1.10-compatible cable) ....................................... 4- 29
4.7 Offline Tests from GX Developer .......................................................................................................... 4- 30
4.7.1 Station-to-station test ...................................................................................................................... 4- 30
4.7.2 Forward loop/reverse loop test (optical loop system only) ............................................................ 4- 36
4.8 Network Diagnostics from GX Developer (Online Tests) ..................................................................... 4- 41
4.8.1 Loop test (optical loop system only) ............................................................................................... 4- 42
4.8.2 Setup confirmation test (optical loop, coaxial bus system only) .................................................... 4- 43
4.8.3 Station order check test (optical loop system only) ........................................................................ 4- 44
4.8.4 Communication test......................................................................................................................... 4- 45
5 PARAMETER SETTINGS 5- 1 to 5-42
5.1 Setting the Number of Modules (Network Type) .................................................................................. 5- 7
5.2 Network Settings .................................................................................................................................... 5- 9
5.2.1 Starting I/O No. ................................................................................................................................ 5- 9
5.2.2 Network No. ..................................................................................................................................... 5- 9
5.2.3 Total stations ................................................................................................................................... 5- 10
5.2.4 Group No. ........................................................................................................................................ 5- 10
5.2.5 Mode ................................................................................................................................................ 5- 11
5.2.6 Communication speed setting (twisted bus system only) .............................................................. 5- 12

A - 12 A - 12
5.2.7 Example of parameter settings ....................................................................................................... 5- 13
5.3 Common Parameters (Network Range Assignment Screen) .............................................................. 5- 14
5.3.1 Send range for each station (LB/LW settings) ............................................................................... 5- 14
5.3.2 Send range for each station (LX/LY settings) ................................................................................ 5- 15
5.3.3 Specification of the I/O master station ............................................................................................ 5- 16
5.3.4 Specification of the reserved station ............................................................................................... 5- 16
5.3.5 Pairing setting .................................................................................................................................. 5- 16
5.4 Supplementary Settings ......................................................................................................................... 5- 17
5.5 Control Station Return Setting ............................................................................................................... 5- 20
5.6 Station Inherent Parameters (High Performance model QCPU, Process CPU, Redundant CPU,
and Universal model QCPU) ................................................................................................................. 5- 21
5.7 Refresh Parameters ............................................................................................................................... 5- 25
5.7.1 Concept of the link refreshing ......................................................................................................... 5- 28
5.7.2 How to set the refresh parameters ................................................................................................. 5- 30
5.8 Valid Module During Other Station Access ........................................................................................... 5- 39
5.9 Standby Station Compatible Module (High Performance model QCPU and Process CPU) .............. 5- 40
5.10 Writing Parameters to the CPU ........................................................................................................... 5- 42
6 PROGRAMMING 6- 1 to 6-31
6.1 Programming Precautions ..................................................................................................................... 6- 1
6.1.1 Interlock related signals .................................................................................................................. 6- 1
6.1.2 Program example ............................................................................................................................ 6- 4
6.2 Cyclic Transmission ............................................................................................................................... 6- 5
6.2.1 32-bit data assurance ...................................................................................................................... 6- 5
6.2.2 Station-based block data assurance for cyclic data ....................................................................... 6- 7
6.2.3 Interlock program example ............................................................................................................. 6- 8
6.3 Link Dedicated Instruction List ............................................................................................................... 6- 9
6.4 Using the Link Special Relays (SB)/Link Special Registers (SW) ....................................................... 6- 13
7 APPLICATION FUNCTIONS 7- 1 to 7-160
7.1 Direct Access to the Link Devices ......................................................................................................... 7- 2
7.2 Inter-Link Data Transfer Function (High Performance model QCPU, Process CPU,
Redundant CPU, and Universal model QCPU) .................................................................................... 7- 6
7.3 Low-Speed Cyclic Transmission Function (High Performance model QCPU, Process CPU,
Redundant CPU, and Universal model QCPU) .................................................................................... 7- 9
7.3.1 Send range settings ........................................................................................................................ 7- 10
7.3.2 Send timing ...................................................................................................................................... 7- 11
7.3.3 Startup ............................................................................................................................................. 7- 14
7.4 Transient Transmission Function (Non-Periodical Communication) .................................................... 7- 16
7.4.1 Communication function.................................................................................................................. 7- 17
7.4.2 Routing function ............................................................................................................................... 7- 20
7.4.3 Group function ................................................................................................................................. 7- 27
7.4.4 Message sending function using the logical channel numbers ..................................................... 7- 28
7.4.5 Programming ................................................................................................................................... 7- 30
7.4.5 (1) Data sending/receiving (JP/GP.SEND, JP/GP.RECV) ............................................................ 7- 36
7.4.5 (2) Reading from/writing to word devices of other stations (JP/GP.READ, JP/GP.SREAD,
JP/GP.WRITE, JP/GP.SWRITE) .................................................................................................... 7- 53

A - 13 A - 13
7.4.5 (3) Requesting transient transmission to other stations (J(P)/G(P).REQ) .................................... 7- 72
7.4.5 (4) Reading/writing word devices of other stations (J(P).ZNRD, J(P).ZNWR) .............................. 7- 82
7.4.5 (5) Remote RUN/Remote STOP (Z(P).RRUN, Z(P).RSTOP) ....................................................... 7- 91
7.4.5 (6) Reading and writing clock data of other station CPU modules (Z(P).RTMRD, Z(P).RTMWR)
......................................................................................................................................................... 7- 100
7.4.6 Setting the clock to stations on a network with GX Developer ...................................................... 7- 109
7.5 Starting the Interrupt Sequence Program ............................................................................................. 7- 110
7.5.1 Interrupt setting parameters ............................................................................................................ 7- 111
7.5.2 Interrupts using the RECVS instruction .......................................................................................... 7- 113
7.5.3 Interrupts by the link devices (LB/LW/LX) for cyclic transmission ................................................. 7- 114
7.5.4 Interrupts by the link special device (SB/SW) ................................................................................ 7- 116
7.5.5 Message reception "one scan completion" instruction (Z.RECVS) ............................................... 7- 117
7.5.6 Application example ........................................................................................................................ 7- 121
7.6 Multiplex Transmission Function (Optical Loop System) ..................................................................... 7- 123
7.7 Simple Dual-Structured Network (High Performance model QCPU and Process CPU) .................... 7- 124
7.8 Stopping/Restarting the Cyclic Transmission and Stopping Link Refreshing (Network Test) ............ 7- 129
7.9 Increasing the Number of Send Points by Installing Multiple Modules with the Same Network
(High Performance model QCPU, Process CPU, Redundant CPU, and Universal model QCPU) ... 7- 132
7.10 Configuring a Network with a Redundant System .............................................................................. 7- 134
7.10.1 Outline of the redundant system operation .................................................................................. 7- 134
7.10.2 Precautions for network configuration including a redundant system ......................................... 7- 137
7.10.3 Pairing setting in a redundant system .......................................................................................... 7- 145
7.10.4 Redundant settings in a redundant system ..................................................................................
7- 149
7.10.5 System switching request to the control system CPU ................................................................. 7- 150
7.10.6 Function for returning to control station in a redundant system .................................................. 7- 152
7.10.7 Data retention time for system switching ...................................................................................... 7- 153
7.10.8 Routing via a redundant system ................................................................................................... 7- 159
8 TROUBLESHOOTING 8- 1 to 8-53
8.1 Network Diagnostics (Network Monitor) ................................................................................................ 8- 2
8.1.1 Host information .............................................................................................................................. 8- 5
8.1.2 Other station information ................................................................................................................. 8- 7
8.1.3 Network monitor details ................................................................................................................... 8- 11
8.1.4 Error history monitor ........................................................................................................................ 8- 15
8.2 Troubleshooting ..................................................................................................................................... 8- 18
8.2.1 Items to be checked first ................................................................................................................. 8- 23
8.2.2 Data link failure on the entire system ............................................................................................. 8- 24
8.2.3 Data link failure caused by reset or power-off of each station ....................................................... 8- 24
8.2.4 Cyclic data is 0 caused by reset or power-on of each station ....................................................... 8- 26
8.2.5 Data link failure of a specific station ............................................................................................... 8- 27
8.2.6 Data link failure in MELSECNET/H Extended mode ..................................................................... 8- 27
8.2.7 Data link failure in MELSECNET/H twisted bus system ................................................................ 8- 28
8.2.8 Data link in a redundant system ..................................................................................................... 8- 28
8.2.9 Send/received data failure .............................................................................................................. 8- 29
8.2.10 Link dedicated instruction not complete ....................................................................................... 8- 30
8.2.11 Checking online for reverse optical fiber cable connection ......................................................... 8- 31
8.2.12 When different network types exist in the same network ............................................................ 8- 33
8.3 Error Codes ............................................................................................................................................ 8- 34
8.3.1 How to check error codes ............................................................................................................... 8- 34

A - 14 A - 14
8.3.2 Error code list................................................................................................................................... 8- 39
8.4 H/W Information ..................................................................................................................................... 8- 49
APPENDICES App- 1 to App-42
Appendix 1 Comparison of Network Module Specifications, and Compatibility ................................... App- 1
Appendix 1.1 List of comparison between MELSECNET/H and MELSECNET/H
Extended mode and MELSECNET/10 mode specifications ....................................... App- 1
Appendix 1.2 Upgraded functions of the network module ................................................................. App- 3
Appendix 2 Differences between the AJ71QLP21/AJ71QLP21G/AJ71QBR11, the A1SJ71QLP21/
A1SJ71QBR11, and the QJ71LP21/QJ71LP21-25/QJ71LP21G/ QJ71BR11 ................. App- 4
Appendix 2.1 Differences in LED displays and switch settings ......................................................... App- 4
Appendix 2.2 Precautions when replacing the AJ71QLP21/AJ71QLP21G/AJ71QBR11 and the
A1SJ71QLP21/A1SJ71QBR11 with the QJ71LP21/QJ71LP21-25/ QJ71LP21G/
QJ71BR11 ..................................................................................................................... App- 5
Appendix 3 Link Special Relay (SB) List ................................................................................................ App- 6
Appendix 4 Link Special Register (SW) List ........................................................................................... App- 18
Appendix 5 Screwdriver .......................................................................................................................... App- 37
Appendix 6 External Dimensions ............................................................................................................ App- 38
INDEX Index- 1 to Index- 3

A - 15 A - 15
MANUALS
The following manuals are also relevant to this product.
Order each manual as needed, referring to the following list.
Relevant manuals
Manual name Manual number
(Model code)
Q corresponding MELSECNET/H Network System Reference Manual (Remote I/O network)
Specifications, setup and procedures before starting the operation, parameter setting, programming and
troubleshooting of the remote I/O network of the MELSECNET/H network system. (Sold separately)
SH-080124
(13JF96)
Type MELSECNET/10 Network system (PLC to PLC network) Reference Manual
System configuration, performance, specifications and programming of MELSECNET/10 network system
(PLC to PLC network). (Sold separately)
IB-66440
(13JE33)
For QnA/Q4AR MELSECNET/10 Network System Reference Manual
System configuration, performance, specifications and programming of MELSECNET/10 network system
(PLC to PLC network). (Sold separately)
IB-66690
(13JF78)
COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES
(1) Method of ensuring compliance
To ensure that Mitsubishi Electric programmable controllers maintain EMC and
Low Voltage Directives when incorporated into other machinery or equipment,
certain measures may be necessary. Please refer to one of the following
manuals.
• QCPU User's Manual (Hardware Design, Maintenance and Inspection)
• Safety Guidelines
(This manual is included with the CPU module or base unit.)
The CE mark on the side of the programmable controller indicates compliance
with EMC and Low Voltage Directives.
(2) Additional measures
(a) When using QJ71LP21 and QJ71NT11B
No additional measures are necessary for the compliance of this product
with EMC and Low Voltage Directives.
(b) When using QJ71BR11
To ensure that this product maintains EMC and Low Voltage Directives,
please refer to one of the manuals listed under (1).

A - 16 A - 16
GENERIC TERMS AND ABBREVIATIONS
Generic term/abbreviation Description of generic term/abbreviation
QJ71LP21
Abbreviation for the QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G, and QJ71LP21GE
MELSECNET/H network modules. However, QJ71LP21, QJ71LP21-25, QJ71LP21S-25,
QJ71LP21G, and QJ71LP21GE are used in this manual to indicate special machine types
QJ71BR11 Abbreviation for the QJ71BR11 MELSECNET/H network module
QJ71NT11B Abbreviation for the QJ71NT11B MELSECNET/H network module
Network modules Generic term for the QJ71LP21, QJ71BR11, and QJ71NT11B
CC-Link IE Controller Network
module Abbreviation for the QJ71GP21-SX and QJ71GP21S-SX CC-Link IE Controller Network modules
CC-Link IE Field Network module Abbreviation for the QJ71GF11-T2 CC-Link IE Field Network master/local modules
MELSECNET/H Abbreviation for the Q corresponding MELSECNET/H network system
MELSECNET/10 Abbreviation for the AnU and QnA/Q4AR corresponding MELSECNET/10 network system
QCPU Generic term for the Basic model QCPU, High Performance model QCPU, Process CPU,
Redundant CPU, and Universal model QCPU
Basic model QCPU Generic term for the Q00JCPU, Q00CPU, and Q01CPU
High Performance model QCPU Generic term for the Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, and Q25HCPU
Process CPU Generic term for the Q02PHCPU, Q06PHCPU, Q12PHCPU, and Q25PHCPU
Redundant CPU Generic term for the Q12PRHCPU and Q25PRHCPU
Universal model QCPU
Generic term for the Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU, Q03UDVCPU,
Q03UDECPU, Q04UDHCPU, Q04UDVCPU, Q04UDEHCPU, Q06UDHCPU, Q06UDVCPU,
Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU, Q13UDHCPU, Q13UDVCPU, Q13UDEHCPU,
Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU, Q26UDVCPU, Q26UDEHCPU, Q50UDEHCPU, and
Q100UDEHCPU
Built-in Ethernet port QCPU
Generic term for the Q03UDVCPU, Q03UDECPU, Q04UDVCPU, Q04UDEHCPU, Q06UDVCPU,
Q06UDEHCPU, Q10UDEHCPU, Q13UDVCPU, Q13UDEHCPU, Q20UDEHCPU, Q26UDVCPU,
Q26UDEHCPU, Q50UDEHCPU, and Q100UDEHCPU
Safety CPU Generic term for the QS001CPU
C Controller module Generic term for the C Controller modules: Q06CCPU-V, Q06CCPU-V-B, Q12DCCPU-V,
Q24DHCCPU-V, Q24DHCCPU-VG, Q24DHCCPU-LS, and Q26DHCCPU-LS
Control CPU
A CPU module that controls connected I/O modules and intelligent function modules. In a multiple
CPU system, there are multiple CPU modules and each connected module can be controlled by a
different CPU module.
System A CPU A CPU module where the system A connector of a tracking cable is connected in a redundant
system
System B CPU A CPU module where the system B connector of a tracking cable is connected in a redundant
system
Control system CPU A CPU module that controls operations in a redundant system
Standby system CPU A CPU module that stands by in case the control system fails in a redundant system
GX Developer
Generic product name for SWnD5C-GPPW-E, SWnD5C-GPPW-EA, SWnD5C-GPPW-EV, and
SWnD5C-GPPW-EVA ("n" means version 4 or later.)
"-A" and "-V" mean "volume license product" and "version-upgrade product" respectively.
GX Works2 Generic product name for SWnDND-GXW2 and SWnDNC-GXW2 (n: version)
CC-Link Ver. 1.10-compatible cable Abbreviation for the CC-Link Version. 1.10-compatible dedicated cable

A - 17 A - 17
Generic term/abbreviation Description of generic term/abbreviation
SEND Abbreviation for JP.SEND and GP.SEND
RECV Abbreviation for JP.RECV and GP.RECV
READ Abbreviation for JP.READ and GP.READ
SREAD Abbreviation for JP.SREAD and GP.SREAD
WRITE Abbreviation for JP.WRITE and GP.WRITE
SWRITE Abbreviation for JP.SWRITE and GP.SWRITE
REQ Abbreviation for J.REQ, JP.REQ, G.REQ and GP.REQ
ZNRD Abbreviation for J.ZNRD and JP.ZNRD
ZNWR Abbreviation for J.ZNWR and JP.ZNWR
RRUN Abbreviation for Z.RRUN and ZP.RRUN
RSTOP Abbreviation for Z.RSTOP and ZP.RSTOP
RTMRD Abbreviation for Z.RTMRD and ZP.RTMRD
RTMWR Abbreviation for Z.RTMWR and ZP.RTMWR
RECVS Abbreviation for Z.RECVS

A - 18 A - 18
DEFINITIONS OF TERMINOLOGY
Term Description
Cyclic transmission A function by which data are periodically exchanged among stations on the network using
link devices
Transient transmission A function of communication with another station, which is used when requested by a
dedicated instruction or GX Developer
Link dedicated instruction Dedicated instruction used for transient transmission.
RAS Abbreviation for Reliability, Availability, and Serviceability.
This term is used to express the overall usability of automation systems.
Control station Only one station that controls the network to which it is connected.
Each station's send range for cyclic transmission is assigned to the control station.
Normal station Station that performs cyclic transmission according to the range assignment of the control
station.
Reserved station
Station that is not actually connected to the network.
It must be included in the total number of stations in the network, since it is to be connected
in the future.
Relay station A station that includes two or more network modules. Data are passed through this station
to stations on other networks.
Reconnection Processing of restarting data link when a faulty station becomes normal.
Disconnection Processing of stopping data link when a data link error occurs.
Device Devices (X, Y, M, D, etc.) that are contained in a CPU module.
Link Device Devices (LB/LW/LX/LY) that are contained in a network module.
Link scan time
Time required for data of each station to be sent in order and to make one rotation in the
network.
The link scan time changes depending on the data volume or transient transmission
request.
Link scans are performed "asynchronously" with sequence scans of the CPU module.
Link refresh
Processing of data transfer between link devices of the network module and CPU module
devices.
Link refresh is performed in "END processing" of the sequence scan of the CPU module.
Buffer memory Memory area in an intelligent function module, in which data are temporarily stored.
The network module does not have any buffer memory area that is offered to the user.
Baton pass A control mechanism in which transmission right (token) is passed around the network for
data transmission.
Control station shift time Time taken from when the control station went down due to a reason such as power-off
until data link is started by the sub-control station.
Group No.
Number that is assigned for transient transmission to any given stations.
By specifying a group of stations as transient transmission target, data can be sent to the
stations of the same group No.