Mitsubishi Electric QJ71MB91 User manual

MODBUS Interface Module User's Manual
-QJ71MB91
-GX Configurator-MB (SW1D5C-QMBU-E)

A- 1
SAFETY PRECAUTIONS
(Always read these instructions before using this product.)
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 user's manual of the CPU module used.
In this manual, the safety precautions are classified into two levels: " WARNING" and " CAUTION".
Under some circumstances, failure to observe the precautions given under " CAUTION" may lead to
serious consequences.
Observe the precautions of both levels because they are important for personal and system safety.
Make sure that the end users read this manual and then keep the manual in a safe place for future
reference.
[DESIGN PRECAUTIONS]
WARNING
For the operating status of each station after a communication failure, refer to relevant manuals for
each network.
Failure to do so may result in an accident due to an incorrect output or malfunction.
When connecting a peripheral with the CPU module or connecting an external device, such as a
personal computer, with an intelligent function module to modify data of a running programmable
controller, configure an interlock circuit in the program to ensure that the entire system will always
operate safely.
For other forms of control (such as program modification or operating status change) of a running
programmable controller, read the relevant manuals carefully and ensure that the operation is safe
before proceeding.
Especially, when a remote programmable controller is controlled by an external device, immediate
action cannot be taken if a problem occurs in the programmable controller due to a communication
failure. To prevent this, configure an interlock circuit in the sequence program, and determine
corrective actions to be taken between the external device and CPU module in case of a
communication failure.
Do not write any data to the "system area" of the buffer memory in the intelligent function module.
Also, do not use any "use prohibited" signals as an output signal from the programmable controller
CPU to the intelligent function module.
Doing so may cause malfunction of the programmable controller system.
WARNING
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 minor or moderate injury or property damage.

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

A- 3
[WIRING PRECAUTIONS]
]
WARNING
Shut off the external power supply (all phases) used in the system before wiring.
Failure to do so may result in electric shock or damage to the product.
After wiring, attach the included terminal cover to the module before turning it on for operation.
Failure to do so may result in electric shock.
CAUTION
Connectors for external devices must be crimped or pressed with the tool specified by the
manufacturer, or must be correctly soldered.
Incomplete connections may cause short circuit, fire, or malfunction.
Securely connect the connector to the module.
Check the rated voltage and terminal layout before wiring to the module, and connect the cables
correctly.
Connecting a power supply with a different voltage rating or incorrect wiring may cause a fire or
failure.
Place the cables in a duct or clamp them.
If not, dangling cable may swing or inadvertently be pulled, resulting in damage to the module or
cables or malfunction due to poor contact.
Check the interface type and correctly connect the cable.
Incorrect wiring (connecting the cable to an incorrect interface) may cause failure of the module and
external device.
Tighten the terminal screws within the specified torque range.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or malfunction.
When disconnecting the cable from the module, do not pull the cable by the cable part.
For the cable with connector, hold the connector part of the cable.
For the cable connected to the terminal block, loosen the terminal screw.
Failure to do so may result in damage to the module or cable or malfunction due to poor contact.
Prevent foreign matter such as dust or wire chips from entering the module.
Such foreign matter can cause a fire, failure, or malfunction.
A protective film is attached to the top of the module to prevent foreign matter, such as wire chips,
from entering the module during wiring.
Do not remove the film during wiring.
Remove it for heat dissipation before system operation.

A- 4
[STARTUP AND MAINTENANCE PRECAUTIONS]
[DISPOSAL PRECAUTIONS]
WARNING
Do not touch any terminal while power is on.
Doing so will cause electric shock.
Shut off the external power supply (all phases) used in the system before cleaning the module or
retightening the terminal screws or module fixing screws.
Failure to do so may cause the module to fail or malfunction.
Undertightening can cause drop of the screw, short circuit or malfunction.
Overtightening can damage the screw and/or module, resulting in drop, short circuit, or malfunction.
CAUTION
Before performing online operations (especially, program modification, forced output or operating
status change) by connecting a peripheral device to a running CPU, read the manual carefully and
ensure the safety.
Improper operation may damage machines or cause accidents.
Do not disassemble or modify the modules.
Doing so may cause failure, malfunction, injury, or a fire.
Use any radio communication device such as a cellular phone or PHS (Personal Handy-phone
System) more than 25cm away in all directions from the programmable controller.
Failure to do so may cause malfunction.
Shut off the external power supply (all phases) used in the system before mounting or removing a
module.
Failure to do so may cause the module to fail or malfunction.
After the first use of the product, do not mount/remove the module to/from the base unit, and the
terminal block to/from the module more than 50 times (IEC 61131-2 compliant) respectively.
Exceeding the limit of 50 times may cause malfunction.
Before handling the module, touch a conducting object such as a grounded metal to discharge the
static electricity from the human body.
Failure to do so may cause the module to fail or malfunction.
CAUTION
When disposing of this product, treat is as an industrial waste.

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

A- 6
REVISIONS
* The manual number is given on the bottom left of the back cover.
Japanese Manual Version SH-080547-J
© 2005 MITSUBISHI ELECTRIC CORPORATION
Print Date * Manual Number Revision
Nov., 2005 SH(NA)-080578ENG-A First edition
Feb., 2006 SH(NA)-080578ENG-B Modifications
Section 2.1, 2.3, 10.1
Oct., 2006 SH(NA)-080578ENG-C Modifications
SAFETY PRECAUTIONS, Section 2.1, 6.6, 10.1
Jan., 2008 SH(NA)-080578ENG-D Modifications
SAFETY PRECAUTIONS, ABOUT THE GENERIC TERMS AND
ABBREVIATIONS, MEANINGS AND DEFINITIONS OF TERMS, Section 2.1,
2.4, 3.1, 3.2.1, 3.3.1, 3.3.2, 3.4.1, 4.1.6, 5.1, 5.2.1, 6.1, 6.3, 6.4.1, 6.4.2, 6.5.2,
6.6, 7.2.1, 7.3.1, 7.3.2, Chapter 8, 9.1.2, 9.3.1, 9.3.2, 10.2, 10.3, 11.1, 11.2,
11.4.1, 11.4.3, 11.5.1, Appendix 3
Added
Section 2.3
Section 2.3 changed to Section 2.4.
Mar., 2008 SH(NA)-080578ENG-E Modifications
COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES, Section 2.1, 2.4,
4.16, 6.3, 6.4.1, 8.5, 8.6, Appendix 3
May, 2008 SH(NA)-080578ENG-F Change of a term
"PLC" was changed to "programmable controller".
Modifications
ABOUT THE GENERIC TERMS AND ABBREVIATIONS, Section 2.1, 4.16, 6.1,
6.6, 7.3.1, 8.2.1, 8.3.1, 8.3.3, 8.4, 8.5, 8.6, 10.2, 10.3, 11.4.3
Apr., 2009 SH(NA)-080578ENG-G Modifications
Section 1.1, 2.1, 2.4, 3.1, 3.4.1, 3.5.1, 4.16, 5.2.1, 8.2.1, 9.1.1 to 9.3.2,
10.1 to 10.3, 11.1, 11.4.3
Added
Section 10.4, Appendix 1
Appendix numbers 1 and 2 changed to 2 and 3.
Jan., 2013 SH(NA)-080578ENG-H Modifications
SAFETY PRECAUTIONS, COMPLIANCE WITH EMC AND LOW VOLTAGE
DIRECTIVES, ABOUT THE GENERIC TERMS AND ABBREVIATIONS,
Section 2.1, 2.3, 2.4, 3.3.2, 4.16, 7.1, 8.2.2, 11.4.3
Added
CONDITIONS OF USE FOR THE PRODUCT, Section 9.4
Sep., 2016 SH(NA)-080578ENG-I Modifications
SAFETYABOUT THE GENERIC TERMS AND ABBREVIATIONS, Section 1.1,
2.1, 2.2, 2.3, 2.4, 3.3.1, 4.2.1, 4.16, 5.2.1, 6.3, 9.2.1, 9.2.2, 9.2.3, 9.3.1, 9.3.2,
10.3, Appendix 3
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.

A- 7
SAFETY PRECAUTIONS .................................................................................................................................A - 1
CONDITIONS OF USE FOR THE PRODUCT..................................................................................................A - 5
REVISIONS.......................................................................................................................................................A - 6
INTRODUCTION...............................................................................................................................................A - 7
CONTENTS ...................................................................................................................................................... A - 7
COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES................................................................... A - 12
THE MANUAL'S USAGE AND STRUCTURE ................................................................................................A - 13
ABOUT THE GENERIC TERMS AND ABBREVIATIONS ..............................................................................A - 15
MEANINGS AND DEFINITIONS OF TERM ...................................................................................................A - 16
PRODUCT CONFIGURATION ....................................................................................................................... A - 16
CHAPTER1 OVERVIEW 1 - 1 to 1 - 4
1.1 Features........................................................................................................................................... 1 - 1
CHAPTER2 SYSTEM CONFIGURATION 2 - 1 to 2 - 10
2.1 Applicable Systems ......................................................................................................................... 2 - 1
2.2 Network Configuration ..................................................................................................................... 2 - 3
2.3 Precautions for System Configuration ............................................................................................. 2 - 7
2.4 How to Check the Function Version/Software Version .................................................................... 2 - 8
CHAPTER3 SPECIFICATIONS 3 - 1 to 3 - 23
3.1 Performance Specifications ............................................................................................................. 3 - 1
3.2 RS-232 Interface Specification ........................................................................................................ 3 - 3
3.2.1 RS-232 connector specification................................................................................................ 3 - 3
3.2.2 RS-232 cable specification ....................................................................................................... 3 - 5
3.3 RS-422/485 Interface Specification ................................................................................................. 3 - 6
3.3.1 RS-422/485 terminal block specification .................................................................................. 3 - 6
3.3.2 RS-422/485 cable specification ................................................................................................ 3 - 7
3.3.3 Precautions when transferring data using RS-422/485 line ..................................................... 3 - 8
3.4 I/O Signals for Programmable Controller CPU .............................................................................. 3 - 10
3.4.1 I/O signal list ........................................................................................................................... 3 - 10
3.5 Applications and Assignment of Buffer Memory ............................................................................ 3 - 13
INTRODUCTION
Thank you for purchasing the Mitsubishi MELSEC-Q series programmable controllers.
Before using this product, please read this manual and the relevant manuals carefully and develop
familiarity with the functions and performance of the MELSEC-Q series programmable controller to handle
the product correctly.
When applying the program examples introduced in this manual to an actual system, ensure the
applicability and confirm that it will not cause system control problems.
CONTENTS

A- 8
3.5.1 Buffer memory list................................................................................................................... 3 - 13
CHAPTER4 MODBUS STANDARD FUNCTIONS 4 - 1 to 4 - 60
4.1 MODBUS Standard Function Support List ...................................................................................... 4 - 1
4.2 Frame Specifications ..................................................................................................................... 4 - 10
4.2.1 Frame mode ........................................................................................................................... 4 - 11
4.3 Protocol Data Unit Formats by Functions ......................................................................................4-15
4.4 Read Coils (FC: 01) ....................................................................................................................... 4 - 18
4.5 Read Discrete Inputs (FC: 02) ....................................................................................................... 4 - 19
4.6 Read Holding Registers (FC: 03)................................................................................................... 4 - 20
4.7 Read Input Registers (FC: 04)....................................................................................................... 4 - 21
4.8 Write Single Coil (FC: 05) .............................................................................................................. 4 - 22
4.9 Write Single Register (FC: 06)....................................................................................................... 4 - 23
4.10 Read Exception Status (FC: 07) .................................................................................................... 4 - 24
4.11 Diagnostics (FC: 08) ...................................................................................................................... 4 - 25
4.11.1 Return query data (sub-function code: 00) ............................................................................. 4 - 25
4.11.2 Restart communications option (sub-function code: 01)......................................................... 4 - 26
4.11.3 Return diagnostic register (sub-function code: 02) ................................................................. 4 - 28
4.11.4 Change ASCII input delimiter (sub-function code: 03)............................................................ 4 - 30
4.11.5 Force listen only mode (sub-function code: 04)...................................................................... 4 - 31
4.11.6 Clear counters and diagnostic register (sub-function code: 10) ............................................. 4 - 33
4.11.7 Return bus message count (sub-function code: 11) ............................................................... 4 - 35
4.11.8 Return bus communication error count (sub-function code: 12)............................................. 4 - 36
4.11.9 Return bus exception error count (sub-function code: 13)...................................................... 4 - 37
4.11.10 Return slave message count (sub-function code: 14) ............................................................ 4 - 38
4.11.11 Return slave no response count (sub-function code: 15) ....................................................... 4 - 39
4.11.12 Return slave NAK count (sub-function code: 16).................................................................... 4 - 40
4.11.13 Return slave busy count (sub-function code: 17) ................................................................... 4 - 41
4.11.14 Return bus character overrun count (sub-function code: 18) ................................................. 4 - 42
4.11.15 Return IOP overrun error count (sub-function code: 19) ........................................................ 4 - 43
4.11.16 Clear overrun counter and flag (sub-function code: 20) ......................................................... 4 - 44
4.12 Get Communications Event Counter (FC: 11) ............................................................................... 4 - 45
4.13 Get Communications Event Log (FC: 12) ...................................................................................... 4 - 47
4.14 Write Multiple Coils (FC: 15) .......................................................................................................... 4 - 50
4.15 Write Multiple Registers (FC: 16)................................................................................................... 4 - 52
4.16 Report Slave ID (FC: 17) ............................................................................................................... 4 - 53
4.17 Read File Record (FC: 20) (SC: 06) .............................................................................................. 4 - 55
4.18 Write File Record (FC: 21) (SC: 06) .............................................................................................. 4 - 57
4.19 Mask Write Register (FC: 22) ........................................................................................................ 4 - 59
4.20 Read/Write Multiple Registers (FC: 23) ......................................................................................... 4 - 60
CHAPTER5 FUNCTIONS 5 - 1 to 5 - 22
5.1 Function List .................................................................................................................................... 5 - 1