Mitsubishi Electric Q Series User manual

Programmable Controller
Reference Manual
QJ71LP21, QJ71LP21-25,
QJ71LP21S-25, QJ71LP21G,
QJ71LP21GE, QJ71BR11
INDUSTRIAL AUTOMATION
MITSUBISHI ELECTRIC
MITSUBISHI ELECTRIC
SH(NA)-080049
01072008
Version K

A - 1 A - 1
•SAFETY PRECAUTIONS •
(Always read before starting use.)
Before using this product, please read this manual and the relevant manuals introduced in this manual
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 instructions are ranked as "DANGER" and "CAUTION".
!DANGER
CAUTION
!
Indicates that incorrect handling may cause hazardous conditions,
resulting in death or severe injury.
Indicates that incorrect handling may cause hazardous conditions,
resulting in medium or slight personal injury or physical damage.
Note that the !CAUTION level may lead to a serious consequence according to the circumstances.
Always follow the instructions of both levels because they are important to personal safety.
Please store this manual in a safe place and make it accessible when required. Always forward it to the
end user.
[Design Precautions]
!DANGER
•Make sure to see this manual for information about each station's operating status when a
communication error occurs in the network. Erroneous outputs and malfunctions may result in
serious accidents.
•If a coaxial cable is disconnected, this may destabilize the line, and a data link communication
error may occur in multiple stations. Make sure to create 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 a serous accident due to faulty output or malfunctions.
•When performing control operations to a programmable controller (modifying data) in operation
by connecting GX Developer to the CPU module or connecting personal computers to the
intelligent functional modules, configure an interlocking circuit in a sequence program so that the
safety of the overall system is maintained. Also, before performing other control operations
(program modifications and operating status modifications (status control)) on the
programmable controller in operation, be sure to read the manual thoroughly and confirm the
safety. Especially if the above mentioned control operations are performed from an external
device to a remote programmable controller, problems arising on the programmable controller
side may not be dealt with immediately due to abnormal data communication. Thus, in addition
to configuring an interlocking circuit in a sequence program, determine how the system should
handle data communication errors between the programmable controller CPU and external
devices.
!CAUTION
•Do not bundle the control wires and communication cables with the main circuit or power wires,
or install them close to each other. They should be installed at least 100 mm (3.94 in.) away
from each other. Failure to do so may generate noise that may cause malfunctions.

A - 2 A - 2
[Installation Precautions]
!CAUTION
•Use the programmable controller in the operating environment that meets the general
specifications given in the user's manual of the CPU module.
Using the programmable controller in any other operating environment may cause an electric
shock, fire or malfunction, or may damage or degrade the product.
•While pressing the installation lever located at the bottom of module, insert the module fixing tab
into the fixing hole in the base unit until it stops.
Then, securely mount the module with the fixing hole as a supporting point.
If the module is not installed properly, it may cause the module to malfunction, fail or fall off.
In an environment of frequent vibrations, secure the module with the screw.
Be sure to tighten the screws using the specified torque. If the screws are loose, it may cause
the module to malfunction or fall off. If the screws are tightened excessively, it may damage the
screws and/or the module, and cause the module to malfunction or fall off.
•Completely turn off the externally supplied power used in the system before mounting or
removing the module. Failure to do so may damage the product.
•Do not directly touch the conducting parts and electronic parts of the module. This may cause
the module to malfunction or fail.
[Wiring Precautions]
!DANGER
•Completely turn off the externally supplied power used in the system when installing or placing
wiring. Failure to do so may cause electric shocks or damage the product.
!CAUTION
•Always connect the FG terminals to the ground using class D (class 3) or higher grounding
exclusively designed for programmable controller.
Failure to do so may cause malfunctions.
•When connecting cables to the terminal block for external power supply, check the rated voltage
and terminal layout of the product for correct wiring.
Connecting a cable to power supply of different voltage or incorrect wiring may cause a fire or
fault.
•Tighten the terminal screws with the specified torque.
Loose tightening may lead to a short circuit, fire or malfunction.
•Solder coaxial cable connectors properly. Incomplete soldering may result in malfunctioning.
•Be careful not to let foreign objects such as dust and wire chips get inside the module. They may
cause a fire, mechanical breakdown or malfunction.
•The top surface of the module is covered with a protective film to prevent foreign objects such as
wire chips from entering the module during wiring work. Do not remove this film until all the
wiring work is complete. Before operating the system, be sure to remove the film to release the
heat.

A - 3 A - 3
[Wiring Precautions]
!CAUTION
•Make sure to place the communication and power cables into a duct or fasten them using a
clamp. Failure to do so may damage the module or cables by pulling a dangling cable
inadvertently or cause the module to malfunction due to bad connection.
•When disconnecting the communication and power cables from the module, do not pull a cable
part by hand. When disconnecting a cable with a connector, hold the connector connected to
the module by hand and pull it out to remove the cable. When disconnecting a cable connected
to a terminal block, loosen the screws on the terminal block first before removing the cable. If a
cable is pulled while being connected to the module, it may cause the module to malfunction or
damage the module and cables.
[Setup and Maintenance Precautions]
!CAUTION
•Please read this manual thoroughly and confirm the safety before starting online operations
(especially, program modifications, forced outputs, and operating status modifications), which
are performed by connecting the GX Developer via the MELSECNET/H network system to a
running CPU module of other station. Performing incorrect online operations may damage the
machinery or result in accidents.
•Never disassemble or modify the module. This may cause breakdowns, malfunctions, injuries or
fire.
•Use any radio communication device such as a cellular phone or a PHS phone more than 25cm
(9.85 inch) away in all directions of the programmable controller.
Not doing so can cause a malfunction.
•Completely turn off the externally supplied power used in the system before mounting or
removing the module. Failure to do so may damage the module or result in malfunctions.
•Do not touch the terminals while the power is on. Doing so may cause malfunctions.
•Switch off all phases of the externally supplied power used in the system when cleaning the
module or retightening the terminal or module mounting screws. Failure to completely shut off all
phases of the external power supply may cause module breakdowns and malfunctions. If the
screws are loose, it may cause the module to short-circuit, malfunction or fall off. If the screws
are tightened excessively, it may damage the screws and cause the module to short circuit,
malfunction or fall off.
•Do not install/remove the module to/from the base unit more than 50 times after the first use of
the product. (IEC 61131-2 compliant)
Failure to do so may cause malfunction.
•Before handling the module, always touch grounded metal, etc. to discharge static electricity
from the human body.
Not doing so may cause a failure or malfunction of the module.
[Disposal Precautions]
!CAUTION
•When disposing of this product, treat it as industrial waste.

A - 4 A - 4
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
Delection
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 - 5 A - 5
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
Japanese Manual Version SH-080026-O
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 - 6 A - 6
INTRODUCTION
Thank you for purchasing the MELSEC-Q series programmable controller.
Before using the equipment, please read this manual carefully to develop full familiarity with the functions
and performance of the Q series programmable controller you have purchased, so as to ensure correct use.
Please forward a copy of this manual to the end user.
CONTENTS
SAFETY PRECAUTIONS..............................................................................................................................A- 1
REVISIONS....................................................................................................................................................A- 4
CONTENTS....................................................................................................................................................A- 6
About Manuals ...............................................................................................................................................A-11
Compliance with the EMC and Low Voltage Directives ...............................................................................A-11
About the Generic Terms and Abbreviations ................................................................................................A-12
DEFINITIONS OF TERMINOLOGY..............................................................................................................A-13
Product Configuration ....................................................................................................................................A-14
1 OVERVIEW 1- 1 to 1-14
1.1 Overview .................................................................................................................................................. 1- 1
1.2 Features ................................................................................................................................................... 1- 4
1.3 Abbreviations Used in the Text, Tables and Diagrams of This Manual................................................. 1-14
2 SYSTEM CONFIGURATION 2- 1 to 2-20
2.1 MELSECNET/H network configurations ................................................................................................. 2- 1
2.1.1 Single network system ...................................................................................................................... 2- 1
2.1.2 Redundant system (Redundant CPU).............................................................................................. 2- 2
2.1.3 Simple dual-structured system (High Performance model QCPU and Process CPU)................... 2- 3
2.1.4 Multiple network system (High Performance model QCPU, Process CPU, Redundant CPU,
and Universal model QCPU) ............................................................................................................ 2- 4
2.2 Applicable Systems.................................................................................................................................. 2- 6
2.2.1 Precautions when using link dedicated instructions......................................................................... 2-10
2.2.2 Precautions when using network modules in the multiple CPU system ......................................... 2-12
2.2.3 List of functions for each CPU module ............................................................................................. 2-18
2.3 Checking the function version and serial number................................................................................... 2-19
3 SPECIFICATIONS 3- 1 to 3-43
3.1 Performance Specifications..................................................................................................................... 3- 1
3.1.1 Performance specifications of the QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G,
QJ71LP21GE and QJ71BR11 network modules ............................................................................ 3- 1
3.1.2 Optical fiber cable specifications ...................................................................................................... 3- 4
3.1.3 Coaxial cable specifications.............................................................................................................. 3- 5
3.2 Function Specifications ............................................................................................................................ 3- 8
3.2.1 Cyclic transmission function (periodical communication) ................................................................ 3- 9
3.2.2 RAS function...................................................................................................................................... 3-12
3.3 Specifications of the Link Data Sending/Receiving Processing Time.................................................... 3-23
3.3.1 Link data sending/receiving processing ........................................................................................... 3-23

A - 7 A - 7
3.3.2 How to calculate the transmission delay time .................................................................................. 3-26
3.3.3 Reducing the link refresh time .......................................................................................................... 3-38
3.3.4 Reduction of the link scan time ......................................................................................................... 3-43
3.3.5 Control station shift time.................................................................................................................... 3-43
4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION 4- 1 to 4-36
4.1 Procedures Before Starting the Operation.............................................................................................. 4- 1
4.2 Component Names and Settings of the Network Module
(QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G, QJ71LP21GE, QJ71BR11) ...................... 4- 2
4.3 Module Switch Settings ........................................................................................................................... 4- 4
4.3.1 Setting the station number (STATION NO.)..................................................................................... 4- 4
4.3.2 Setting the mode (MODE)................................................................................................................. 4- 5
4.3.3 Installing and uninstalling the module............................................................................................... 4- 6
4.3.4 Stopping the CPU (unintentional output prevention)........................................................................4- 7
4.3.5 Checking the input power supply voltage......................................................................................... 4- 8
4.4 Powering On ............................................................................................................................................ 4- 8
4.4.1 Checking the on status of the POWER LED of the power supply module...................................... 4- 8
4.4.2 Checking the on status of the RUN LED of the network module..................................................... 4- 8
4.5 Standalone Check of the Network Module (Offline Tests) ..................................................................... 4- 9
4.5.1 Self-loopback test.............................................................................................................................. 4-10
4.5.2 Internal self-loopback test ................................................................................................................. 4-12
4.5.3 Hardware test .................................................................................................................................... 4-13
4.6 Cable Connection .................................................................................................................................... 4-14
4.6.1 Optical loop system ........................................................................................................................... 4-14
4.6.2 Coaxial bus system ........................................................................................................................... 4-17
4.7 Offline Tests from GX Developer ............................................................................................................ 4-22
4.7.1 Station-to-station test ........................................................................................................................ 4-22
4.7.2 Forward loop/reverse loop test ......................................................................................................... 4-27
4.8 Network Diagnostics from GX Developer (Online Tests) ....................................................................... 4-32
4.8.1 Loop test (optical loop system only) ................................................................................................. 4-33
4.8.2 Setup confirmation test ..................................................................................................................... 4-34
4.8.3 Station order check test (optical loop system only).......................................................................... 4-35
4.8.4 Communication test........................................................................................................................... 4-36
5 PARAMETER SETTINGS 5- 1 to 5-41
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 Example of parameter settings ......................................................................................................... 5-12
5.3 Common Parameters (Network Range Assignment Screen) ................................................................ 5-13
5.3.1 Send range for each station (LB/LW settings) ................................................................................. 5-13
5.3.2 Send range for each station (LX/LY settings) .................................................................................. 5-14
5.3.3 Designation of the I/O master station ............................................................................................... 5-15

A - 8 A - 8
5.3.4 Designation of the reserved station .................................................................................................. 5-15
5.3.5 Pairing setting.................................................................................................................................... 5-15
5.4 Supplementary Settings........................................................................................................................... 5-16
5.5 Control Station Return Setting................................................................................................................. 5-19
5.6 Station Inherent Parameters (High Performance model QCPU, Process CPU, Redundant CPU,
and Universal model QCPU)................................................................................................................... 5-20
5.7 Refresh Parameters................................................................................................................................. 5-24
5.7.1 Concept of the link refreshing ........................................................................................................... 5-27
5.7.2 How to set the refresh parameters ................................................................................................... 5-29
5.8 Valid Module During Other Station Access............................................................................................. 5-38
5.9 Standby Station Compatible Module (High Performance model QCPU and Process CPU)................ 5-39
5.10 Writing the Parameters to the CPU....................................................................................................... 5-41
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 guarantee ........................................................................................................................ 6- 5
6.2.2 Block guarantee of cyclic data per station........................................................................................ 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 7-151
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) .............................................................. 7-34
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)..................................................................................................... 7-50
7.4.5 (3) Requesting transient transmission to other stations (J(P)/G(P).REQ) ...................................... 7-67
7.4.5 (4) Reading/writing word devices of other stations (J(P).ZNRD, J(P).ZNWR)................................ 7-76
7.4.5 (5) Remote RUN/Remote STOP (Z(P).RRUN, Z(P).RSTOP)......................................................... 7-84
7.4.5 (6) Reading and writing clock data of other station CPU modules (Z(P).RTMRD, Z(P).RTMWR)
.......................................................................................................................................................... 7-92

A - 9 A - 9
7.4.6 Setting the clock on the stations on a network with GX Developer............................................... 7-100
7.5 Starting the Interrupt Sequence Program ............................................................................................. 7-101
7.5.1 Interrupt setting parameters............................................................................................................ 7-102
7.5.2 Interrupts using the RECVS instruction.......................................................................................... 7-104
7.5.3 Interrupts by the link devices (LB/LW/LX) for cyclic transmission ................................................. 7-105
7.5.4 Interrupts by the link special device (SB/SW) ................................................................................ 7-107
7.5.5 Message reception "one scan completion" instruction (Z.RECVS)............................................... 7-108
7.5.6 Application example ........................................................................................................................ 7-112
7.6 Multiplex Transmission Function (Optical Loop System) ..................................................................... 7-114
7.7 Simple Dual-Structured Network (High Performance model QCPU and Process CPU) .................... 7-115
7.8 Stopping/Restarting the Cyclic Transmission and Stopping Link Refreshing (Network Test) ............ 7-120
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) .... 7-123
7.10 Constructing a network with a redundant system............................................................................... 7-125
7.10.1 Outline of the redundant system operation .................................................................................. 7-125
7.10.2 Precautions for network construction containing a redundant system........................................ 7-128
7.10.3 Pairing setting at a redundant system .......................................................................................... 7-136
7.10.4 Redundant settings in the redundant system...............................................................................7-140
7.10.5 System switching request to the control system CPU ................................................................. 7-141
7.10.6 Function for returning to control station in a redundant system .................................................. 7-143
7.10.7 Data retention time for system switching...................................................................................... 7-144
7.10.8 Routing via a redundant system ................................................................................................... 7-150
8 TROUBLESHOOTING 8- 1 to 8-48
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 Data link failure of a specific station ................................................................................................. 8-25
8.2.5 Data link failure in MELSECNET/H Extended mode ....................................................................... 8-25
8.2.6 Data link in redundant system........................................................................................................... 8-26
8.2.7 Abnormal transmission/reception data ............................................................................................. 8-27
8.2.8 Link dedicated instruction execution not complete .......................................................................... 8-28
8.2.9 Checking online for reverse optical fiber cable connection ............................................................. 8-29
8.2.10 When different network types exist in the same network .............................................................. 8-31
8.3 Error Codes .............................................................................................................................................. 8-32
8.4 H/W Information ....................................................................................................................................... 8-42

A - 10 A - 10
APPENDIX App- 1 to App-36
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- 2
Appendix 2 Differences Between the AJ71QLP21/AJ71QLP21G/AJ71QBR11, the A1SJ71QLP21/
A1SJ71QBR11 and the QJ71LP21/QJ71LP21-25/QJ71LP21G/ QJ71BR11.....................App- 3
Appendix 2.1 Differences in LED displays and switch settings ............................................................App- 3
Appendix 2.2 Precautions when replacing the AJ71QLP21/AJ71QLP21G/AJ71QBR11 and the
A1SJ71QLP21/A1SJ71QBR11 with the QJ71LP21/QJ71LP21-25/ QJ71LP21G/
QJ71BR11........................................................................................................................App- 4
Appendix 3 Link Special Relay (SB) List...................................................................................................App- 5
Appendix 4 Link Special Register (SW) List .............................................................................................App-15
Appendix 5 External Dimensions...............................................................................................................App-34
INDEX Index- 1 to Index- 2

A - 11 A - 11
About Manuals
The following manuals are also related to this product.
In necessary, order them by quoting the details in the tables below.
Related Manuals
Manual Name Manual Number
(Model Code)
Q corresponding MELSECNET/H Network System Reference Manual (Remote I/O network)
This manual describes the 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
This manual describes the 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
This manual describes the system configuration, performance, specifications and programming of
MELSECNET/10 network system (PLC to PLC network). (Sold separately)
IB-66690
(13JF78)
Compliance with the EMC and Low Voltage Directives
(1) For programmable controller system
To configure a system meeting the requirements of the EMC and Low Voltage
Directives when incorporating the Mitsubishi programmable controller (EMC
and Low Voltage Directives compliant) into other machinery or equipment, refer
to Chapter 9 "EMC AND LOW VOLTAGE DIRECTIVES" of the QCPU User's
Manual (Hardware Design, Maintenance and Inspection).
The CE mark, indicating compliance with the EMC and Low Voltage Directives,
is printed on the rating plate of the programmable controller.
(2) For the product
For the compliance of this product with the EMC and Low Voltage Directives,
refer to Section 9.1.3 "Cables" in Chapter 9 "EMC AND LOW VOLTAGE
DIRECTIVES" of the QCPU User's Manual (Hardware Design, Maintenance
and Inspection).

A - 12 A - 12
About the Generic Terms and Abbreviations
Generic term/abbreviation Description of generic term/abbreviation
QJ71LP21
Abbreviation for 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 QJ71BR11 MELSECNET/H network modules.
Network modules Generic term for QJ71LP21 and QJ71BR11.
CC-Link IE controller network
module Abbreviation for QJ71GP21-SX or QJ71GP21S-SX CC-Link IE controller network module.
MELSECNET/H Abbreviation for Q corresponding MELSECNET/H network system.
MELSECNET/10 Abbreviation for AnU and QnA/Q4AR corresponding MELSECNET/10 network system.
QCPU
Generic term for Q00JCPU, Q00CPU, Q01CPU, Q02CPU, Q06PHCPU, Q06HCPU, Q12HCPU,
Q25HCPU, Q02PHCPU, Q06PHCPU, Q12PHCPU, Q25PHCPU, Q12PRHCPU, Q25PRHCPU,
Q02UCPU, Q03UDCPU, Q04UDHCPU, Q06UDHCPU, Q13UDHCPU, Q26UDHCPU,
Q03UDECPU, Q04UDEHCPU, Q06UDEHCPU, Q13UDEHCPU, and Q26UDEHCPU.
Basic model QCPU Generic term for Q00JCPU, Q00CPU, and Q01CPU.
High Performance model QCPU Generic term for Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, and Q25HCPU.
Process CPU Generic term for Q12PHCPU, and Q25PHCPU.
Redundant CPU Generic term for Q12PRHCPU and Q25PRHCPU.
Universal model QCPU
Generic term for Q02UCPU, Q03UDCPU, Q04UDHCPU, Q06UDHCPU, Q13UDHCPU,
Q26UDHCPU, Q03UDECPU, Q04UDEHCPU, Q06UDEHCPU, Q13UDEHCPU, and
Q26UDEHCPU.
Built-in Ethernet port QCPU Generic term for Q03UDECPU, Q04UDEHCPU, Q06UDEHCPU, Q13UDEHCPU, and
Q26UDEHCPU.
Safety CPU Generic term for QS001CPU.
C Controller module Generic term for Q06CCPU-V, Q06CCPU-V-B type C Controller module.
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.
SEND Abbreviation for JP.SEND, GP.SEND.
RECV Abbreviation for JP.RECV, GP.RECV.
READ Abbreviation for JP.READ or GP.READ.
SREAD Abbreviation for JP.SREAD, GP.SREAD.
WRITE Abbreviation for JP.WRITE, GP.WRITE.
SWRITE Abbreviation for JP.SWRITE, GP.SWRITE.
REQ Abbreviation for J.REQ, JP.REQ, G.REQ, GP.REQ.
ZNRD Abbreviation for J.ZNRD, JP.ZNRD.
ZNWR Abbreviation for J.ZNWR, JP.ZNWR.
RRUN Abbreviation for Z.RRUN, ZP.RRUN.
RSTOP Abbreviation for Z.RSTOP, ZP.RSTOP.
RTMRD Abbreviation for Z.RTMRD, ZP.RTMRD.
RTMWR Abbreviation for Z.RTMWR, ZP.RTMWR.
RECVS Abbreviation for Z.RECVS.

A - 13 A - 13
DEFINITIONS OF TERMINOLOGY
Term Description
Cyclic transmission
Using the link devices (LB/LW/LX/LY) of the network module, data can be transferred
periodically between stations on the same network.
·LB/LW is used to send data of one station to all stations. (1:N communication)
·LX/LY is used to send data of one station to another station. (1:1 communication)
Transient transmission
This function allows communication with another station's programmable controller when a
request is made with a link dedicated instruction or from GX Developer.
Communications can be made with programmable controllers on the same or other
networks.
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
Station that relays transient transmission data to another network.
Link device data of a network module are transferred to another network module via this
station.
Multiple network modules are connected to one programmable controller.
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.

A - 14 A - 14
Product Configuration
Model name Part name Quantity
QJ71LP21 Model QJ71LP21 MELSECNET/H Network Module
(optical loop type) 1
QJ71LP21-25 Model QJ71LP21-25 MELSECNET/H Network Module
(optical loop type) 1
QJ71LP21S-25 Model QJ71LP21S-25 MELSECNET/H Network Module
(optical loop type, with external power supply function) 1
QJ71LP21G Model QJ71LP21G MELSECNET/H Network Module
(optical loop type) 1
QJ71LP21GE Model QJ71LP21GE MELSECNET/H Network Module
(optical loop type) 1
Model QJ71BR11 MELSECNET/H Network Module
(coaxial bus type) 1
QJ71BR11
F-type connector (A6RCON-F) 1
REMARKS
For the coaxial bus system, terminal resistors (75 Ω) are required in the network
terminal stations.
Terminal resistors are not supplied with the QJ71BR11; they must be purchased
separately.
For a list of the model names and how to use the terminal resistors, refer to Section
4.6.2.

1 - 1 1 - 1
MELSEC-Q
1 OVERVIEW
1 OVERVIEW
The MELSECNET/H network system includes an PLC to PLC network for interactively
communicating between control stations and normal stations, and a remote I/O
network for interactively communicating between remote master stations and remote
I/O stations.
This manual is to be read when structuring PLC to PLC networks on MELSECNET/H
network systems (hereinafter known as MESECNET/H.)
The Q corresponding MELSECNET/H Network System Reference Manual (Remote
I/O networks) is to be read when structuring remote I/O networks with MELSECNET/H.
REMARKS
Networks previously known as MELSECNET/10H are abbreviated here as
MELSECNET/H.
1.1 Overview
The PLC to PLC network system of MELSECNET/H provides more functionality,
higher processing speed and more capacity than the conventional PLC to PLC network
system of MELSECNET/10 network system.
In addition, in pursuit of the maximum ease of use of the MELSECNET/10 network
system, the FA system can be networked easily by combining with GX Developer.
The MELSECNET/H system supports the MELSECNET/H and MELSECNET/H
Extended modes (high functionality and high-speed mode) and the MELSECNET/10
mode (functional and performance compatibility mode) to achieve the network
performance improvement and upward compatibility of MELSECNET/10.
MELSECNET/H PLC to PLC network optical loop systems can be set at
communications speeds of 25Mbps and 10Mbps.
Network system Communication speed
Optical loop, coaxial bus 10Mbps
MELSECNET/H Optical loop 1 25Mbps
1: QJ71LP21-25 and QJ71LP21S-25 only
1

1 - 2 1 - 2
MELSEC-Q
1 OVERVIEW
Unless otherwise categorized, this is abbreviated as MELSECNET/H for explanatory
purposes in this manual.
Q25HCPU
GX Developer Remote master station
Control station (MELSECNET/H mode)
MELSECNET/10
PLC to PLC network
MELSECNET/H (25Mbps)
remote I/O network
Q25HCPU Normal station
Q25HCPU Q25HCPU
Normal station
Normal station
Remote I/O
station
MELSECNET/H (10Mbps)
PLC to PLC network
Q25HCPU Normal station
Control station (MELSECNET/10 mode)
AnUCPU
QnACPU
Normal
station
Normal
station
MELSECNET/H (25Mbps) PLC to PLC network
REMARKS
This manual is written assuming that MELSECNET/H is used in the MELSECNET/H
or MELSECNET/H Extended mode. Thus, if MELSECNET/H is to be used in the
MELSECNET/10 mode, please refer to the "For QnA/Q4AR MELSECNET/10
Network System Reference Manual".
POINT
(1) Select a QCPU as a programmable controller of the MELSECNET/H for PLC
to PLC network system.
(2) When any of the conventional series QnA, AnU and ACPUs exist in the same
network, select the MELSEC NET/10 mode, which is compatible with the
MELSECNET/10.
(3) Set the control station and normal stations within the same network to the
same network type.
Stations of different network types cannot be used together within the same
network.
1

1 - 3 1 - 3
MELSEC-Q
1 OVERVIEW
The table below shows the CPU modules that can be combined for use on each
network.
Network to be connected
MELSECNET/10 MELSECNET/H
CPU
module
Type of networks
that can be used
with CPU PLC to PLC network Remote I/O
network PLC to PLC network Remote I/O network
MELSECNET/H
(10 Mbps)
(MESLECNET/10 mode)
QCPU MELSECNET/H
(25 Mbps)
(MESLECNET/H mode,
MELSECNET/H Extended mode)
AnUCPU MELSECNET/10
QnACPU MELSECNET/10
: Use possible : Use not possible
REMARKS
What is network type?
The network type is a parameter set for specifying the network where the network
module is used.
Set the network type of the network module in the Network parameter of GX
Developer.
There are the following network types.
Network type Description
MELSECNET/H mode Set this mode when all CPUs within the network are QCPUs.
MELSECNET/H Extended
mode
The maximum number of link points per station has been increased
compared with the MELSECNET/H mode.
In excess of 2000 bytes, a maximum of 35840 bytes can be set.
Set this mode when the system uses many link points per station.
MELSECNET/10 mode This mode is used to operate the network module on a
MELSECNET/10 network where the QnA/AnU exists.