Mitsubishi Electric Melsec QJ71LP21 User manual

(Remote I/O network)
Q Corresponding MELSECNET/H Network System Reference Manual(Remote I/O network)
R
Q Corresponding MELSECNET/H
Network System
Q Corresponding MELSECNET/H
Network System
Reference Manual (Remote I/O network) Reference Manual
Mitsubishi Programmable
Logic Controller
Specifications subject to change without notice.
HEAD OFFICE : MITSUBISHI DENKI BLDG MARUNOUCHI TOKYO 100-8310 TELEX : J24532 CABLE MELCO TOKYO
NAGOYA WORKS : 1-14 , YADA-MINAMI 5 , HIGASHI-KU, NAGOYA , JAPAN
MODEL
MODEL
CODE
Q-NET/H-R-I/O-E
13JF96
SH(NA)-080124-B(0105)MEE
QJ71LP21
QJ71LP21-25
QJ71LP21G
QJ71LP21GE
QJ71BR11
QJ72LP25-25
QJ72LP25G
QJ72LP25GE
QJ72BR15
When exported from Japan, this manual does not require application to the
Ministry of Economy, Trade and Industry for service transaction permission.

A - 1 A - 1
•SAFETY PRECAUTIONS •
(Always read these instructions before using this equipment.)
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
•When the network develops a communication error, the station with the communication error will
enter into the following status.
Use the communication status data to form an interlock circuit in the sequence program that will
operate the system on the safe side. Erroneous output or malfunctioning could cause accidents.
(1) The remote master station will hold the data from before the communication error.
(2) The remote I/O station turns off all outputs. The output module of the remote I/O station can
clear/hold the output status at the time of error by using the remote I/O module parameters.
As the parameters are set to "clear" by default, the output module turns off the outputs at the
time of error. If it is required to hold the output in order to operate the system safely, set the
parameters to "hold".
•If the coaxial cable is disconnected, the line may become unstable and the data link
communication error may occur in more than one stations. Make sure to create an interlock
circuit in the sequence program so that the system operates safely even when the data link
communication error occurs in more than one stations.
Failure to do so may cause the stations to mis-output or malfunction, resulting in accidents.

A - 2 A - 2
[Design Precautions]
!DANGER
•When performing control operations to a PLC (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 PLC 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 PLC, problems arising on the PLC 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 PLC CPU and external devices.
!CAUTION
•Always reset the CPU module after changing the parameters for the CPU module or the remote
I/O module. If this is not done, data from before the change could cause malfunctioning.
•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.
[Installation Precautions]
!CAUTION
•Use the PLC in the operating environment that meets the general specifications described in the
user's manual for the CPU module used. Using the PLC in any other operating environments
may cause electric shocks, fires or malfunctions, or may damage or degrade the product.
•With holding down the module installation lever on the lower part of the module, securely insert
the module fastening latch in the installation hole on the base unit to install the module using the
module installation hole as a supporting point. If the module is not installed properly, it may
cause the module to malfunction, fail or fall off.
Secure the module with screws especially when it is used in an environment where constant
vibrations may occur.
Be sure to tighten the screws using the specified torque. 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.
•Before mounting or dismounting the module, make sure to shut off all phases of the external
power supply. Failure to do so may damage the product.
For remote I/O stations of function version D or later, online module change can be performed.
However, the modules which can be replaced online are limited, and replacement procedures
are determined for each module. For details, refer to the section of online module replacement
in this manual.

A - 3 A - 3
[Installation Precautions]
!CAUTION
•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
•Before starting wiring or similar work, be sure to shut off all phases of the external power supply
to the entire system. Failure to completely shut off the power supply to the system may cause
electric shocks and damage the product.
!CAUTION
•Be sure to ground the FG terminals independently for PLC by class D (class 3) or higher.
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 rating 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 particles such as chaff 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 provide
adequate heat ventilation.
•Make sure to place the communication and power cables to be connected to the module in a
duct or fasten them using a clamp. If the cables are not placed in a duct or not fastened with a
clamp, their positions may become unstable and may move, or they may be pulled
inadvertently. This may damage the module and the cables or cause the module to malfunction
because of faulty cable connections.
•When disconnecting the communication and power cables from the module, do not pull the
cables by hand. When disconnecting a cable with a connector, hold the connector 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.

A - 4 A - 4
[Setup and Maintenance Precautions]
!CAUTION
•Please read this manual thoroughly and confirm the safety enough before starting online
operations (especially, program modifications, forced outputs, and operating status
modifications), which are performed by connecting GX Developer via the MELSECNET/H
network system to a CPU module running on another 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.
•When using a cellular phone, use it at least 25 cm (9.84 in.) away from the PLC. Failing to do so
may cause malfunctions.
•Before mounting or dismounting the module, make sure to shut off all phases of the external
power supply. Failure to do so may damage the module or result in malfunctions.
For the remote I/O network systems of function version D or later, online module change can be
performed. However, the modules which can be replaced online are limited, and replacement
procedures are determined for each module. For details, refer to the section of online module
replacement in this manual.
•Do not mount/remove the module onto/from base unit more than 50 times (IEC61131-2-
compliant), after the first use of the product.
Failure to do so may cause the module to malfunction due to poor contact of connector.
•Do not touch the terminals while the power is on. This maycausebreakdowns,malfunctions,
injuries or fire.
•Before cleaning the module or retightening the terminal screws and module installation screws,
make sure to shut off all phases of the external power supply. 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.
•Before handling the module, always touch grounded metal, etc. to discharge static electricity
from the human body.
Failure to do so can cause the module to fail or malfunction.
[Disposal Precautions]
!CAUTION
•When disposing of this product, treat it as industrial waste.

A - 5 A - 5
REVISIONS The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Oct., 2000 SH (NA) -080124-A First printing
May., 2001 SH (NA) -080124-B Model addition
QJ71LP21G, QJ72LP25G, QJ71LP21GE, QJ72LP25GE
Correction
Product Components, About The Generic Terms And Abbreviations,
Chapter 1, Section 1.2, 2.4, 3.1.1, 3.1.2, 3.2.1, 3.2.2, 3.3.2, 4.2.1, 4.2.2,
4.8.2, Chapter 5, Section 5.1.5, 5.2.1, 6.1.2, 6.2.1, 6.3, 6.4, 7.1.1, 7.8,
8.1, 8.1.1, 8.1.4, 8.3.1, 8.3.2, Appendix 2, 3, 4, 5, Index
Addition
Section 8.2.6
Apr., 2002 SH (NA) -080124-C Correction
Section 1.2, 1.3, 2.3.1, 2.3.2, 2.3.3, 2.5, 3.1.1, 3.1.2, 3.2, 3.3.2, 4.2.1,
6.1.1, 6.4, Chapter 7, Section 8.4, Appendix 2, 3
Changed item numbers
Section 2.3 Section 2.4, Section 2.4 Section 2.5
Addition
Section 7.10
Nov., 2002 SH (NA) -080124-D Model addition
QJ71LP21S-25
Correction
SAFETY PRECAUTIONS, CONTENTS,
Generic Terms And Abbreviations, Product Components,
Section 1.1, 1.2, 3.1.1, 3.1.2, 4.1.2, 4.8.1, 4.8.2, 7.1.1, 8.1.4,
Appendix 2, 3
Apr., 2003 SH (NA) -080124-E Correction
SAFETY PRECAUTIONS, About Manuals, Section 1.2, 2.1.2, 2.2.2,
2.3.2, 2.5, 3.1.1, 3.1.2, 3.2.2, 3.3.1, Chapter 5, Section 5.1.3, 5.1.5, 6.2,
6.3, 6.4, 6.5, 8.1, 8.2, 8.2.1, 8.2.5, 8.3.1

A - 6 A - 6
The manual number is given on the bottom left of the back cover.
Print Date Manual Number Revision
Jun., 2004 SH (NA) -080124-F Correction
SAFETY PRECAUTIONS, Manuals, Generic Terms And Abbreviations,
Section 1.2, 2.1.2, 2.2.2, 2.3.2, 2.4.2, 2.5, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.2,
3.2.2, 4.2.2, 4.9.1, 4.10, 4.10.1, 4.10.2, 4.10.3, Chapter 5, Section 5.1.1,
5.2, 5.2.1, 6.4, 6.5, Chapter 7, Section 8.1, 8.1.1, 8.1.2, 8.1.3, 8.1.4,
8.2.1, 8.2.3, 8.2.5, 8.2.7, 8.3.1, 8.3.2, Appendix 2, 3
Addition
Section 1.4, 2.4, 2.7, 3.3.3, 3.3.4, 7.11, 7.12, 8.2.7, Appendix 7
Changed section No.
Section 2.4 Section 2.5, Section 2.5 Section 2.6
Japanese Manual Version SH-080123-H
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.
2000 MITSUBISHI ELECTRIC CORPORATION

A - 7 A - 7
INTRODUCTION
Thank you for purchasing the MELSEC-Q series PLC.
Before using the equipment, please read this manual carefully to develop full familiarity with the functions
and performance of the Q series PLC 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- 5
CONTENTS....................................................................................................................................................A- 7
Manuals ....................................................................................................................................................A-11
Conformation to the EMC Directive and Low Voltage Instruction ................................................................A-11
Generic Terms And Abbreviations.................................................................................................................A-12
Product Components .....................................................................................................................................A-12
1 OVERVIEW 1- 1 to 1- 9
1.1 Overview..................................................................................................................................................1- 1
1.2 Features ..................................................................................................................................................1- 2
1.3 Abbreviations Used in the Text, Tables and Diagrams of This Manual................................................1- 9
1.4 Functions Added/Changed with Upgrade to Function Version D..........................................................1- 9
2 SYSTEM CONFIGURATION 2- 1 to 2-17
2.1 Single Remote I/O Networks..................................................................................................................2- 1
2.1.1 Configuration....................................................................................................................................2- 1
2.1.2 Setting items.....................................................................................................................................2- 2
2.1.3 Available device ranges...................................................................................................................2- 3
2.2 Multiple Remote I/O Network (QnPHCPU Only)....................................................................................2- 4
2.2.1 Configuration....................................................................................................................................2- 4
2.2.2 Setting items.....................................................................................................................................2- 5
2.2.3 Available device ranges...................................................................................................................2- 6
2.3 Multiplexed Remote I/O Network for Redundant System (QnPRHCPU Only).....................................2- 7
2.3.1 Configuration....................................................................................................................................2- 7
2.3.2 Setting items.....................................................................................................................................2- 8
2.3.3 Available device ranges...................................................................................................................2- 9
2.4 Multiple Remote I/O Network..................................................................................................................2-10
2.4.1 Configuration....................................................................................................................................2-10
2.4.2 Setting items.....................................................................................................................................2-10
2.4.3 Available device ranges...................................................................................................................2-11
2.5 Precautions when Configuring the System............................................................................................2-12
2.6 When Using a Multiple CPU System......................................................................................................2-15
2.7 Checking Function Version and Serial No. ............................................................................................2-17
3 SPECIFICATIONS 3- 1 to 3-50
3.1 Performance Specifications....................................................................................................................3- 1
3.1.1 Optical loop system performance specifications.............................................................................3- 1

A - 8 A - 8
3.1.2 Coaxial cable system performance specifications..........................................................................3- 2
3.1.3 Optical fiber cable specifications .....................................................................................................3- 3
3.1.4 Coaxial cable specifications.............................................................................................................3- 4
3.2 Function Specifications...........................................................................................................................3- 7
3.2.1 Cyclic transmission function (Periodic communication)..................................................................3- 8
(1) Communicating with input/output module.......................................................................................3- 8
(2) Communicating with intelligent function module.............................................................................3- 9
3.2.2 RAS functions...................................................................................................................................3-14
(1) Output reset function for communication errors..............................................................................3-14
(2) Automatic return function.................................................................................................................3-14
(3) Loopback function (Optical loop system)........................................................................................3-15
(4) Station detach function (Coaxial bus systems)...............................................................................3-17
(5) Transient transmission enabled even at CPU module error ..........................................................3-18
(6) Checking the transient transmission abnormal direction time........................................................3-19
(7) Diagnostic functions.........................................................................................................................3-20
(8) Configuration of a redundant power supply on a remote I/O station .............................................3-21
(9) Online module change in a remote I/O station ...............................................................................3-24
3.3 Link Data Send/Receive Processing Time Specifications.....................................................................3-30
3.3.1 Link data send/receive processing ..................................................................................................3-30
3.3.2 Transmission delay time..................................................................................................................3-33
3.3.3 Switching time from the multiplexed remote master station to the multiplexed remote
sub-master station in a multiplexed remote I/O network ..............................................................3-45
3.3.4 Output holding time during system switching in the multiplexed remote I/O network for
redundant system...........................................................................................................................3-46
4 SETUP AND PROCEDURES BEFORE STARTING THE OPERATION 4- 1 to 4-27
4.1 Procedures Before Starting the Operation.............................................................................................4- 1
4.2 Network Module Names and Settings....................................................................................................4- 2
4.2.1 QJ71LP21, QJ71LP21-25, QJ71LP21G, QJ71LP21GE, QJ71BR11 (Remote master station)...4- 2
4.2.2 QJ72LP25-25, QJ72LP25G, QJ72LP25GE, QJ72BR15 ...............................................................4- 5
4.3 Installing and Uninstalling the Module....................................................................................................4- 7
4.4 Stopping the CPU (Unintentional Output Prevention) ...........................................................................4- 8
4.5 Checking the Input Power Supply Voltage.............................................................................................4- 8
4.6 Powering On............................................................................................................................................4- 8
4.6.1 Checking the on status of the POWER LED of the power supply module.....................................4- 8
4.6.2 Checking the on status of the RUN LED of the network module ...................................................4- 8
4.7 Standalone Check of the Network Module (Offline Tests) ....................................................................4- 9
4.7.1 Self-loopback test.............................................................................................................................4-10
4.7.2 Internal self-loopback test................................................................................................................4-11
4.7.3 Hardware test...................................................................................................................................4-12
4.8 Cable Connections..................................................................................................................................4-13
4.8.1 Optical loop system..........................................................................................................................4-13
4.8.2 Coaxial bus system..........................................................................................................................4-15
4.9 Offline Tests from GX Developer............................................................................................................4-20
4.9.1 Forward loop/reverse loop test (Remote master station only)........................................................4-20
4.10 Network Diagnostics from GX Developer (Online Tests)....................................................................4-23
4.10.1 Loop test (optical loop system only)..............................................................................................4-24
4.10.2 Setup confirmation test ..................................................................................................................4-25

A - 9 A - 9
4.10.3 Station order check test (optical loop system only).......................................................................4-26
4.10.4 Communication test .......................................................................................................................4-27
5 PARAMETER SETTINGS 5- 1 to 5-30
5.1 Remote Master Station Parameter Setting............................................................................................5- 5
5.1.1 Setting the number of module cards (Network type) ......................................................................5- 5
5.1.2 Network settings...............................................................................................................................5- 6
(1) Starting I/O No. ................................................................................................................................5- 6
(2) Network No. .....................................................................................................................................5- 6
(3) Total (slave) stations........................................................................................................................5- 6
(4) Group No.
(Can be set for multiplexed remote master station/multiplexed remote sub-master station only)5- 7
(5) Mode.................................................................................................................................................5- 7
(6) Parameter setting example..............................................................................................................5- 8
5.1.3 Common parameter.........................................................................................................................5- 9
(1) LX/LY settings..................................................................................................................................5- 9
(2) LB/LW setting...................................................................................................................................5-11
(3) Reserved station designation..........................................................................................................5-12
(4) Remote sub-master station .............................................................................................................5-12
5.1.4 Supplemental settings......................................................................................................................5-14
5.1.5 Network refresh parameters ............................................................................................................5-16
5.1.6 Valid Module During Other Station Access.....................................................................................5-24
5.1.7 Redundant settings ..........................................................................................................................5-25
5.2 Remote I/O Station Parameter Settings.................................................................................................5-26
5.2.1 Remote I/O station possible parameter settings.............................................................................5-26
6 PROGRAMMING 6- 1 to 6-15
6.1 Programming Precautions......................................................................................................................6- 1
6.1.1 Interlock related signals ...................................................................................................................6- 1
6.1.2 Program example.............................................................................................................................6- 3
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- 6
6.3 Communication Between Input/Output Module and Intelligent Function Module.................................6- 7
6.4 Dedicated Link Instruction List................................................................................................................6-11
6.5 Using the Link Special Relays (SB)/ Link Special Registers (SW) .......................................................6-15
7 APPLICATION FUNCTIONS 7- 1 to 7-45
7.1 Transient Transmission Function (Non-Periodical Communication).....................................................7- 2
7.1.1 Dedicated link instruction.................................................................................................................7- 3
(1) Reading/writing remote I/O station intelligent function module buffer memory
(REMFR/REMTO)............................................................................................................................7- 3
7.2 Remote I/O Station System Monitor.......................................................................................................7-13
7.3 Device Test for Remote I/O Station........................................................................................................7-14
7.4 Multiplex Transmission Function (Optical Loop System) ......................................................................7-16
7.5 Return Sequence Station Number Setting Function..............................................................................7-17

A - 10 A - 10
7.6 Reserved Station Function .....................................................................................................................7-17
7.7 Interrupt Settings.....................................................................................................................................7-18
7.8 I/O Assignment Function ........................................................................................................................7-19
7.9 Stopping/Restarting the Cyclic Transmission and Stopping Link Refreshing (Network Test).............7-20
7.10 Multiplexed remote master function (QnPHCPU only)........................................................................7-21
7.11 Multiplexed remote master function for redundant system (QnPRHCPU only)..................................7-36
7.11.1 Backup function of master operation on system switching between control system and
standby system..............................................................................................................................7-37
7.11.2 Master operation by the station that has started up as the control system..................................7-38
7.11.3 System switching request function of control system...................................................................7-39
7.11.4 Access function by specifying either the control system or standby system ...............................7-41
7.12 Remote password.................................................................................................................................7-42
8 TROUBLESHOOTING 8- 1 to 8-97
8.1 Network Diagnostics (Network Monitor).................................................................................................8- 2
8.1.1 Host information ...............................................................................................................................8- 4
8.1.2 Other station information..................................................................................................................8- 6
8.1.3 Network monitor details....................................................................................................................8- 8
8.1.4 Error history monitor.........................................................................................................................8-11
8.2 Troubleshooting ......................................................................................................................................8-14
8.2.1 Items to be checked first..................................................................................................................8-19
8.2.2 When data link cannot be executed on the entire system..............................................................8-19
8.2.3 When data link is disabled because of reset or power off of each station.....................................8-20
8.2.4 When a specific-station's data link cannot be executed .................................................................8-20
8.2.5 When the transmission and reception data are abnormal..............................................................8-21
8.2.6 When the dedicated link instruction is not completed.....................................................................8-21
8.2.7 When a multiplexed remote I/O network for the redundant system does not operate normally...8-22
8.3 Error Codes.............................................................................................................................................8-23
8.3.1 MELSECNET/H error code list ........................................................................................................8-23
8.3.2 Error codes corresponding to CPU module detected on remote I/O station..................................8-34
8.4 H/W Information......................................................................................................................................8-96
APPENDIX App- 1 to App-46
Appendix 1 Precautions when Changing Over from a MELSECNET/10 Remote I/O Network to
a MELSECNET/H Remote I/O Network................................................................................App- 1
Appendix 2 Link Special Relay (SB) List..................................................................................................App- 3
Appendix 3 Link Special Register (SW) List.............................................................................................App-11
Appendix 4 Special Relay (SM) for Remote I/O Modules List.................................................................App-27
Appendix 5 Special Register (SD) for Remote I/O Module List...............................................................App-29
Appendix 6 Discontinued Models that can be Mounted on Remote I/O Stations...................................App-40
Appendix 7 External Dimensions..............................................................................................................App-41
INEDX Index- 1 to Index- 2

A - 11 A - 11
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 (PLC to PLC network)
This manual describes the specifications for a MELSECNET/H network system for PLC to PLC network.
It explains the procedures and settings up to operation, setting the parameters, programming and
troubleshooting. (Sold separately)
SH-080049
(13JF92)
QCPU User's Manual (Hardware Design, Maintenance and Inspection)
This manual provides the specifications of the CPU modules, power supply modules, base units,
extension cables, memory cards and others. (Sold separately)
SH-080483ENG
(13JR73)
QCPU User's Manual (Function Explanation, Program Fundamentals)
This manual explains the functions, programming methods, devices and so necessary to create
programs with the QCPU. (Sold separately)
SH-080484ENG
(13JR74)
QCPU User's Manual (Multiple CPU System)
This manual explains the multiple CPU system overview, system configuration, I/O numbers,
communication between CPU modules, and communication with the I/O modules or intelligent function
modules. (Sold separately)
SH-080485ENG
(13JR75)
QnPRHCPU User's Manual (Redundant System)
This manual explains the redundant system configuration, functions, communication with external
devices, and troubleshooting for redundant system construction using the Redundant CPU.
(Sold separately)
SH-080486ENG
(13JR76)
GX Developer Version 8 Operating Manual
This manual describes the programming, printing, monitoring and debugging procedures, and other
online functions using GX Developer. (Sold separately)
SH-080373E
(13JU41)
Conformation to the EMC Directive and Low Voltage Instruction
When incorporating a Mitsubishi PLC compliant with the EMC Directive and Low
Voltage Instruction into your product to conform to the directives, see Chapter 3
"EMC Directive and Low Voltage Instruction" of the CPU User's Manual used
(Hardware).
The CE logo is printed on the rating plate on the main body of the PLC that conforms
to the EMC directive and low voltage instruction.
For information on compliance with the EMC directive and low voltage directive,
please refer to Section 3.1.3. "Cable" in Chapter 3 "EMC Directive and Low Voltage
Directive" of the User’s Manual (Hardware) for the CPU module.

A - 12 A - 12
Generic Terms And Abbreviations
Generic term/abbreviation Description of generic term/abbreviation
QJ71LP21 This is an abbreviation for a QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G, QJ71LP21GE MELSECNET/H network module. However, especially in cases to show different models,
QJ71LP21, QJ71LP21-25, QJ71LP21S-25, QJ71LP21G and QJ71LP21GE are printed.
QJ71BR11 Abbreviation for QJ71BR11 type MELSECNET/H network module.
QJ72LP25 Abbreviation for QJ72LP25-25, QJ72LP25G, QJ72LP25GE MELSECNET/H network module. However, especially in cases to show different models, QJ72LP25-25, QJ72LP25G and
QJ72LP25GE are printed.
QJ72BR15 Abbreviation for QJ72BR15 MELSECNET/H network module.
Master module General term for QJ71LP21 and QJ71BR11.
Remote I/O module General term for QJ72LP25 and QJ72BR15.
Network module General term for master module and remote I/O module.
Ethernet module Abbreviation for QJ71E71-100, QJ71E71-B5, and QJ71E71-B2 Ethernet interface modules.
Serial communication module Abbreviation for QJ71C24N, QJ71C24N-R2, QJ71C24N-R4, QJ71C24, and QJ71C24-R2 serial
communication modules.
Modem interface module Abbreviation for QJ71CM0 modem interface module.
MELSECNET/H Abbreviation for Q series MELSECNET/H network system.
MELSECNET/10 Abbreviation for AnU series MELSECNET/10 network system and QnA/Q4AR series
MELSECNET/10 network system
QCPU Abbreviation for Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, Q25HCPU, Q12PHCPU,
Q25PHCPU, Q12PRHCPU, Q25PRHCPU.
QnCPU Abbreviation for Q02CPU.
QnHCPU Abbreviation for Q02HCPU, Q06HCPU, Q12HCPU, Q25HCPU.
QnPHCPU Abbreviation for Q12PHCPU, Q25PHCPU.
QnPRHCPU Abbreviation for Q12PRHCPU and Q25PRHCPU modules.
QnACPU Generic term for MELSEC-QnA series CPU modules.
ACPU Generic term for MELSEC-A series CPU modules.
AnUCPU Generic term for MELSEC-A series A2UCPU, A2UCPU-S1, A3UCPU, A4UCPU, A2USCPU,
A2USCPU-S1, and A2USHCPU-S1 CPU modules.
GX Developer Abbreviation for GX Developer software package.
GX Configurator Abbreviation for GX Configurator software package.
Tracking cable Abbreviation for QC10TR and QC30TR tracking cables.
Product Components
Model name Part name Quantity
QJ71LP21 QJ71LP21 MELSECNET/H Network Module (optical loop type) 1
QJ71LP21-25 QJ71LP21-25 MELSECNET/H Network Module (optical loop type) 1
QJ71LP21S-25 QJ71LP21S-25 MELSECNET/H Network Module (optical loop type, with
external power supply function) 1
QJ71LP21G QJ71LP21G MELSECNET/H Network Module (optical loop type) 1
QJ71LP21GE QJ71LP21GE MELSECNET/H Network Module (optical loop type) 1
QJ71BR11 MELSECNET/H Network Module (coaxial bus type) 1
QJ71BR11 F-type connector 1
QJ72LP25-25 QJ72LP25-25 MELSECNET/H Network Module (optical loop type) 1
QJ72LP25G QJ72LP25G MELSECNET/H Network Module (optical loop type) 1
QJ72LP25GE QJ72LP25GE MELSECNET/H Network Module (optical loop type) 1
QJ72BR15 MELSECNET/H Network Module (coaxial cable bus type) 1
QJ72BR15 F-type connector 1
REMARK
For the coaxial bus system, terminal resistors (75 Ω) are required in the network
terminal stations.
Terminal resistors are not included with the QJ71BR11, QJ72BR15; they must be
purchased separately.
For a list of the model and how to use the terminal resistors, refer to Section 4.8.2.

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MELSEC-Q
1 OVERVIEW
1 OVERVIEW
The MELSECNET/H system includes the following 2 types of networks:
1) PLC to PLC network for communications between a control station and normal
stations
2) Remote I/O network for communications between a remote master station and
remote I/O stations
This is the manual to read when building a remote I/O network for MELSECNET/H
systems (hereafter called MELSECNET/H). If you are building a MELSECNET/H
network for PLC to PLC network, please refer to the Q-corresponding MELSECNET/H
network system reference manual. (PLC to PLC network) (SH-080049)
POINT
The Q00JCPU, Q00CPU and Q01CPU cannot configure a remote I/O network in a
MELSECNET/H network system.
REMARK
The previous network, called MELSECNET/10H is now called MELSECNET/H.
1.1 Overview
The MELSECNET/H remote I/O network system has more functionality and capacity
than the former network system, MELSECNET/10 network system (hereafter referred
to as MELSECNET/10).
As the MELSECNET/H remote I/O network adopts the same module mounting method
as the usual one (mounting I/O modules and intelligent function modules onto the main
base unit/expansion base unit), each module mounted on the remote I/O stations can
be handled in the similar way as the basic one.
In addition, the applicability to the MELSECNET/10 remote I/O network has been
further enhanced so that the FA system can be easily configured.
In the MELSECNET/H remote I/O network optical loop system, the communication
speed can be set to 25 Mbps or 10 Mbps.
Network system Communication speed
Optical loop 1 25 Mbps
MELSECNET/H Optical loop, coaxial cable 10 Mbps
1: QJ71LP21-25, QJ71LP21S-25, QJ72LP25-25 only
Remote I/O station
QCPU
GX Developer
Control station (MELSECNET/10 mode) Control station (MELSECNET/H mode)
GX Developer
QCPU normal station
QCPU normal station
QCPU normal station
Remote I/O station Remote I/O station Remote I/O station
MELSECNET/H (25Mbps)
PC network
Remote master station
MELSECNET/H (10Mbps)
remote I/O network
MELSECNET/H (25Mbps) remote I/O network
MELSECNET/H (10Mbps)
PLC to PLC network
QnACPU
normal station AnUCPU normal station QCPU normal station
1

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MELSEC-Q
1 OVERVIEW
POINT
(1) Use QCPU for MELSECNET/H remote I/O network PLC selection time.
(2) Remote I/O networks and PLC to PLC networks cannot be mixed on the same
MELSECNET/H network. Always build separate networks.
(3) Only MELSECNET/H network modules can be connected to a MELSECNET/H
remote I/O network. They cannot be mixed with MELSECNET/10 network
modules.
The following table shows the types of networks the CPU modules can be connected to.
Network to be connected
MELSECNET/10 MELSECNET/HCPU 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) (MELSECNET/10
mode)
QCPU MELSECNET/H
(25 Mbps)
(MELSECNET/H
mode)
AnUCPU MELSECNET/10
QnACPU MELSECNET/10 : Can be used : Cannot be used
1.2 Features
The MELSECNET/H remote I/O network has the following features.
(1) Achievement of a high-speed communication system
(a) High-speed data sending at a communication rate of 10 Mbps/25 Mbps is
possible.
(25Mbps is available for only the optical loop type QJ71LP21-25,
QJ71LP21S-25 and QJ72LP25-25.)
(2) Large-scale and flexible system configuration
(a) The link device has a larger capacity: 16384 points for the link relay (LB)
and 16384 points for the link register (LW). (See Section 2.1.3, "Available
device range settings.")
(b) A maximum of 4096 I/O points can be set for each remote I/O station.
The link points between a remote master station and a remote I/O station
can be set up to 1600 bytes. The link points of up to 2000 bytes can be set
between a master station and a sub-master station on a multiplexed remote
I/O network.
(c) Either of the following systems can be chosen: the optical loop system
(maximum total extension of 30 km (98430 ft.)) which has a long station-to-
station distance and total distance, and is resistant to noise, or the coaxial
bus system (maximum total extension of 500 m (1640.5 ft.) which can easy
be wired.
(See Section 3.1, "Performance Specifications.")
1

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MELSEC-Q
1 OVERVIEW
(d) It is not necessary to designate reserved stations which are treated as
stations to be connected in future or to connect stations in the order of station
numbers. The optical loop system executes a loopback when a station is
down. Because of these functions, connecting networks has become easier
than ever. (See Section 5.1.3, "Designation of the reserved station.")
(e) The parameters can be written to remote I/O modules using GX Developer
in the same way as to CPU modules.
The parameters of the remote I/O module can be used to change the
detailed settings (response time, error output mode) for I/O modules on a
remote I/O station, intelligent function module switch settings and I/O
allocations, and remote password settings.
(Refer to Section 5.2 "Remote I/O Station Parameter Settings".)
(f) Setting up a master station (DMR) and a sub-master station (DSMR) on the
multiplexed remote I/O network allows the sub-master station to take over
the control of remote I/O stations (R) in case of the master station's failure.
(The QnPHCPU should be used for the multiplexed remote master station
and sub-master station.)
By making a parameter setting, the multiplexed remote sub-master station
can continue the control of the remote I/O stations even if the master
station has recovered to normal and rejoined to the system. (Setting for the
recovered master station to control the remote I/O stations is also
available.)
(Refer to Section 7.10 "Multiplex Remote Master Function (QnPHCPU
Only)".)
Multiplexed remote
master station (DMR)Multiplexed remote
sub-master station (DSMR)
Remote I/O station (R) Remote I/O station (R) Remote I/O station (R)

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MELSEC-Q
1 OVERVIEW
(g) The redundant system uses the multiplex remote master function to control
I/O modules and intelligent function modules. (The QnPRHCPU should be
used in the redundant system.)
If the multiplexed master station (control system) fails, the multiplex remote
master function will switch the master station from "control system" to
"standby system". At this time, the multiplexed remote sub-master station
is switched from "standby" to "control", continuing the remote I/O control.
The sub-master station (control system) that is controlling the remote I/O
stations will keep its control even if the master station (standby system) has
returned to normal status.
(Refer to Section 7.11 "Multiplex Remote Master Function for Redundant
System (QnPRHCPU Only).)
Remote I/O station (R) Remote I/O station (R) Remote I/O station (R)
Tracking cable
Multiplexed remote master station (DMR)
Control system Standby system Multiplexed remote sub-master station (DSMR)
Standby system Control system
(h) A maximum of 7 extension base units can be connected to the remote I/O
module (eight base units including the main base unit), allowing the
installation of up to 64 modules.
The maximum overall length of extension cables is 13.2m, ensuring a
flexible layout of extension base units.

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MELSEC-Q
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(3) Providing versatile communication service
(a) Reading and writing of data for an intelligent function module that has been
mounted to a remote I/O station can be easily performed.
There are four methods available for reading and writing.
1) Use GX Configurator to make the initial settings and automatic refresh
settings in the intelligent function module parameters, and write them
into the remote I/O module in the remote I/O station.
By refreshing the intelligent function module data to the link register W
of the remote I/O module in the auto refresh settings, the remote
master station can read/write refreshed data by cyclic transmission.
QCPU
Remote master station Remote I/O station
Intelligent function module
LW
GX
Configurator
Intelligent function
module parameters
• Initial settings
• Automatic refresh
settings
Remote I/O module Intelligent function module
Buffer memory
QCPU Master module
Link register W Link register LW
Refresh Link register W
Refresh
2) Special link instructions can be used to directly read from or write to the
buffer memory of the intelligent module.
• REMFR instruction: Reads data from the buffer memory of the
remote I/O station intelligent function module.
• REMTO instruction: Writes data to the buffer memory of the remote
I/O station intelligent function module.
QCPU
Remote master station Remote I/O station
Intelligent function module
REMTO
Network module Intelligent function module
Buffer memory
REMTO
QCPU Network module
Z.REMTO

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MELSEC-Q
1 OVERVIEW
3) By refreshing the intelligent function module data into the remote I/O
module's data register D by the automatic refresh setting of the
intelligent function module parameters, the remote master station can
read/write data from/to the data register D with READ or WRITE
instruction.
QCPU
Remote master station Remote I/O station
Intelligent function module
GX
Configurator
Intelligent function
module parameters
• Initial settings
• Automatic refresh
settings
Remote I/O module Intelligent function module
Data
register D Buffer memory
QCPU Master station
WRITE
JP.WRITE
WRITE
Refresh
4) The automatic refresh setting of the intelligent function parameters
enables the intelligent function module data to be refreshed into the
remote I/O module's data register D. By refreshing the data register D
to the link register W with the parameter of the remote I/O module, the
remote master station can read/write the intelligent function module
data by cyclic transmission.
This method has the advantage that the intelligent function module
parameters created for QCPU can be applied to the remote I/O
module without making any modifications.
QCPU
Remote master station Remote I/O station
Intelligent function module
LW
Remote I/O module Intelligent function module
QCPU Master station
Link register W Link register LW
Intelligent function
module parameters
• Initial settings
• Automatic refresh
settings
Refresh
Refresh
Link
register W Data register D Buffer memory
Refresh
GX
Configurator
(b) The interrupt sequence program of the host's CPU module can be started
up using the event issue function. This function reduces the response time
of the system and enables real-time data reception.
(See Section 7.7, "Starting Up the Interrupt Sequence Program.")
END
MAIN
I50
CPU module Network module
Cyclic transmission
MELSECNET/H
Normal
sequence
program
Condition check
Interrupt condition
parameters
• Relay information
• Register data
• Network status
Conditions
matched
Interrupt
sequence
program
IRET