Mitsubishi Electric QJ71MB91, SW1D5C-QMBU-E User Manual

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MODBUS Interface Module User's Manual

-QJ71MB91

-GX Configurator-MB (SW1D5C-QMBU-E)

SAFETY PRECAUTIONS

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.

(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.

A - 1

[DESIGN PRECAUTIONS]

CAUTION

Do not install the control lines or communication cables together with the main circuit lines or power cables. Keep a distance of 100mm or more between them. Failure to do so may result in malfunction due to noise.

[INSTALLATION PRECAUTIONS]

CAUTION

Use the programmable controller in 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 - 2

[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.

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 - 3

[STARTUP AND MAINTENANCE 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.

[DISPOSAL PRECAUTIONS]

CAUTION

When disposing of this product, treat is as an industrial waste.

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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 - 5

REVISIONS

* The manual number is given on the bottom left of the back cover.

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

Japanese Manual Version SH-080547-J

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 - 6

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.

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

A - 7

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

A - 8

5.2 Master Function ............................................................................................................................... 5 - 3

5.2.1 Automatic communication function ...........................................................................................5 - 3

5.2.2 Communication by dedicated instructions .............................................................................. 5 - 16

5.3 Slave Function ............................................................................................................................... 5 - 17

5.3.1 Automatic response function .................................................................................................. 5 - 17

5.3.2 MODBUS device assignment function ................................................................................... 5 - 18

5.3.3 Link operation function ........................................................................................................... 5 - 21

CHAPTER6 PRE-OPERATIONAL PROCEDURES AND SETTINGS 6 - 1 to 6 - 24

6.1 Handling Precautions....................................................................................................................... 6 - 1

6.2 Pre-Operational Procedures and Settings ....................................................................................... 6 - 2

6.3 Part Names...................................................................................................................................... 6 - 4

6.4 Unit Tests......................................................................................................................................... 6 - 6

6.4.1 Hardware test ........................................................................................................................... 6 - 6

6.4.2 Self-loopback test ..................................................................................................................... 6 - 8

6.5 Connection to a Target Device ...................................................................................................... 6 - 11

6.5.1 How to connect the RS-232 interface..................................................................................... 6 - 12

6.5.2 How to connect the RS-422/485 interface.............................................................................. 6 - 14

6.6 Intelligent Function Module Switch Setting .................................................................................... 6 - 19

6.7 Maintenance, Inspection ................................................................................................................ 6 - 24

6.7.1 Maintenance, inspection......................................................................................................... 6 - 24

6.7.2 When removing or installing the module ................................................................................ 6 - 24

CHAPTER7 PARAMETER SETTING 7 - 1 to 7 - 31

7.1 Parameter Settings and Setting Procedure .....................................................................................7 - 1

7.2 Automatic Communication Parameter ............................................................................................. 7 - 4

7.2.1 Automatic communication parameter details........................................................................... 7 - 4

7.3 MODBUS Device Assignment Parameter ..................................................................................... 7 - 11

7.3.1 MODBUS device assignment to the programmable controller CPU device memory ............. 7 - 13

7.3.2 MODBUS extended file register assignment to the programmable controller

CPU file register ..................................................................................................................... 7 - 23

7.3.3 QJ71MB91 buffer memory assignment .................................................................................. 7 - 24

7.3.4 Specifying the error status read device .................................................................................. 7 - 26

7.3.5 Specifying access target when mounted to MELSECNET/H remote I/O station .................... 7 - 29

7.3.6 Specifying the CPU response monitoring timer ...................................................................... 7 - 30

CHAPTER8 UTILITY PACKAGE (GX Configurator-MB) 8 - 1 to 8 - 37

8.1 Functions of the Utility Package ...................................................................................................... 8 - 1

8.2 Installing and Uninstalling the Utility Package ................................................................................. 8 - 2

8.2.1 Handling precautions ................................................................................................................ 8 - 2

8.2.2 Operating environment ............................................................................................................. 8 - 5

8.3 Utility Package Operation ................................................................................................................ 8 - 7

8.3.1 Common utility package operations ......................................................................................... 8 - 7

8.3.2 Operation overview................................................................................................................. 8 - 10

A - 9

8.3.3 Starting the Intelligent function module utility ......................................................................... 8 - 12

8.4 Initial Setting .................................................................................................................................. 8 - 15

8.4.1 Automatic communication parameter ..................................................................................... 8 - 17

8.4.2 MODBUS device assignment parameter ................................................................................ 8 - 19

8.5 Auto Refresh Setting...................................................................................................................... 8 - 22

8.6 Monitor/Test ................................................................................................................................... 8 - 24

8.6.1 X/Y Monitor/test ...................................................................................................................... 8 - 29

8.6.2 MODBUS device assignment parameter status ..................................................................... 8 - 31

8.6.3 Automatic communication status ............................................................................................ 8 - 32

8.6.4 Error log .................................................................................................................................. 8 - 34

8.6.5 Communication status ............................................................................................................ 8 - 35

CHAPTER9 PROGRAMMING 9 - 1 to 9 - 45

9.1 Parameter Setting ............................................................................................................................ 9 - 1

9.1.1 Automatic communication parameters ..................................................................................... 9 - 1

9.1.2 MODBUS device assignment parameters ................................................................................ 9 - 4

9.2 Program Example for Normal System Configuration....................................................................... 9 - 8

9.2.1 Automatic communication parameters ..................................................................................... 9 - 8

9.2.2 MODBUS device assignment parameters .............................................................................. 9 - 14

9.2.3 When using the automatic communication function and the communication by dedicated

instructions on the same channel .......................................................................................... 9 - 18

9.3 Program Examples for Use in MELSECNET/H Remote I/O Network............................................ 9 - 25

9.3.1 Automatic communication parameters ................................................................................... 9 - 25

9.3.2 MODBUS device assignment parameters .............................................................................. 9 - 37

9.4 Program Examples for the Redundant System ............................................................................. 9 - 45

CHAPTER10 DEDICATED INSTRUCTIONS 10 - 1 to 10 - 32

10.1 Dedicated Instruction List and Available Devices .......................................................................... 10 - 1

10.2 Z(P).MBRW ................................................................................................................................... 10 - 2

10.3 Z(P).MBREQ................................................................................................................................ 10 - 14

10.4 ZP.UINI ........................................................................................................................................ 10 - 25

CHAPTER11 TROUBLESHOOTING 11 - 1 to 11 - 47

11.1 Troubleshooting ............................................................................................................................. 11 - 1

11.2 Checking QJ71MB91 Status........................................................................................................ 11 - 11

11.3 Checking the Communication Status of QJ71MB91.................................................................... 11 - 17

11.4 Error Codes ................................................................................................................................. 11 - 21

11.4.1 Error code storage area........................................................................................................ 11 - 21

11.4.2 Exception code list................................................................................................................ 11 - 28

11.4.3 Error code list........................................................................................................................ 11 - 30

11.5 Turning Off the ERR. LED ........................................................................................................... 11 - 41

11.5.1 Turning off the ERR. LED by GX Configurator-MB............................................................... 11 - 41

11.5.2 Turning off the ERR. LED by sequence program ................................................................. 11 - 45

11.5.3 Turning off the ERR. LED by request message from the master ......................................... 11 - 47

A - 10

APPENDICES App - 1 to App - 13

Appendix 1 Function Upgrade of the QJ71MB91 ................................................................................ App - 1

Appendix 2 A Series Modules .............................................................................................................App - 2

Appendix 2.1 Comparisons in performance specifications.............................................................App - 2

Appendix 2.2 Functional comparisons ........................................................................................... App - 3

Appendix 2.3 Utilization of existing programs ................................................................................ App - 4

Appendix 3 Processing Time...............................................................................................................App - 7

Appendix 4 External Dimensions....................................................................................................... App - 13

INDEX Index - 1 to Index - 2

A - 11

COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES

(1) Method of ensuring compliance

To ensure that Mitsubishi programmable controllers maintain EMC and Low Voltage Directives when incorporated into other machinery or equipment, certain measures may be necessary. Please refer to one of the following manuals.

• QCPU User's Manual (Hardware Design, Maintenance and Inspection)

• Safety Guidelines (This manual is included with the CPU module or base unit.)

The CE mark on the side of the programmable controller indicates compliance with EMC and Low Voltage Directives.

(2) Additional measures

No additional measures are necessary for the compliance of this product with EMC and Low Voltage Directives.

A - 12

THE MANUAL'S USAGE AND STRUCTURE

This manual lists the process and functions up to systems operation using the MODBUS interface module (QJ71MB91), divided into subjects. Refer to the corresponding section when you need to know the following:

(1) Features ( CHAPTER 1)

CHAPTER 1 describes the features of the QJ71MB91.

(2) System Configuration ( CHAPTER 2)

Section 2.1 lists the applicable programmable controller CPU and corresponding software package. Section 2.2 lists network configuration example.

(3) Performance and Specifications ( CHAPTER 3)

Section 3.1 lists the performance specifications of the QJ71MB91. Section 3.2 and 3.3 list the specifications of each interface. Section 3.4 and 3.5 list the I/O signals and buffer memory of the QJ71MB91.

(4) MODBUS Standard Functions Supporting QJ71MB91 ( CHAPTER 4)

Section 4.1 lists the MODBUS standard functions supporting QJ71MB91. Section 4.2 to 4.20 list the frame specifications of the MODBUS standard functions supporting QJ71MB91.

(5) Usable Functions ( CHAPTER 5)

CHAPTER 5 describes the functions of the QJ71MB91.

(6) Settings and Procedures Necessary for System Operation

CHAPTER 6)

(

CHAPTER 6 describes the pre-operation settings and procedures.

(7) Parameter Settings of the QJ71MB91 ( CHAPTER 7)

CHAPTER 7 describes the parameter setting procedures and parameter details.

(8) Setting Parameters from the Utility Package ( CHAPTER 8)

CHAPTER 8 describes how to use the utility package.

(9) Setting Parameters from the Sequence Program ( CHAPTER 9)

CHAPTER 9 describes the I/O signals used for parameter settings, the I/O signal timing charts, and program examples.

(10)Reading from/Writing to the MODBUS Device using the Sequence

Program ( CHAPTER 10)

CHAPTER 10 describes the dedicated instructions designed to read or write MODBUS device data with sequence programs.

A - 13

(11)Error Code and Corresponding Process Details (

Section 11.1 lists troubleshooting. Section 11.2 lists the confirmation methods of the module conditions. Section 11.3 lists the confirmation of the communication conditions. Section 11.4 lists the storage location and details of the error codes. Section 11.5 lists the methods to turn off the ERR. LED.

About the notation of the numerical values used in this manual

In this manual, the numerical values with the suffix "H" are displayed in hexadecimal values.

(Example) 10......Decimal

H....Hexadecimal

CHAPTER 11)

A - 14

ABOUT THE GENERIC TERMS AND ABBREVIATIONS

Unless otherwise specified, this manual uses the following generic terms and abbreviations to explain the QJ71MB91 MODBUS interface module.

General term/Abbreviation Description

QJ71MB91 Abbreviation for the QJ71MB91 MODBUS interface module. GX Developer GX Works2 MODBUS Protocol Generic term for the protocol designed to use MODBUS protocol messages. FC Abbreviation for the function code. SC Abbreviation for the sub code.

Programmable controller

CPU

Basic model QCPU Generic term for the Q00JCPU, Q00CPU, and Q01CPU Redundant CPU Generic term for the Q12PRHCPU and Q25PRHCPU

Universal model QCPU

C Controller module

Master The side from which a request is sent to execute a function.

Slave

Master function

Slave function

Request message

Response message The message with which the slave returns a function execution result to the master.

Target device

Personal computer Abbreviation for DOS/V personal computers of IBM PC/AT and compatible. MELSECNET/H Abbreviation of the MELSECNET/H network system. MBRW Abbreviation for Z.MBRW or ZP.MBRW. MBREQ Abbreviation for Z.MBREQ or ZP.MBREQ. UINI Abbreviation for ZP.UINI.

Windows 7

The product name of the software package for the MELSEC programmable controllers

Generic term for the Q00JCPU, Q00CPU, Q01CPU, Q02CPU, Q02HCPU, Q06HCPU,

Q12HCPU, Q25HCPU, Q02PHCPU, Q06PHCPU, Q12PHCPU, Q25PHCPU, Q12PRHCPU,

Q25PRHCPU, Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU, Q03UDVCPU,

Q03UDECPU, Q04UDHCPU, Q04UDVCPU, Q04UDEHCPU, Q06UDHCPU, Q06UDVCPU,

Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU, Q13UDHCPU, Q13UDVCPU,

Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU, Q26UDVCPU,

Q26UDEHCPU, Q50UDEHCPU, and Q100UDEHCPU

Generic term for the Q00UJCPU, Q00UCPU, Q01UCPU, Q02UCPU, Q03UDCPU,

Q03UDVCPU, Q03UDECPU, Q04UDHCPU, Q04UDVCPU, Q04UDEHCPU, Q06UDHCPU,

Q06UDVCPU, Q06UDEHCPU, Q10UDHCPU, Q10UDEHCPU, Q13UDHCPU,

Q13UDVCPU, Q13UDEHCPU, Q20UDHCPU, Q20UDEHCPU, Q26UDHCPU,

Q26UDVCPU, Q26UDEHCPU, Q50UDEHCPU, and Q100UDEHCPU Generic term for the Q06CCPU-V-H01, Q06CCPU-V, Q06CCPU-V-B, Q12DCCPU-V,

Q24DHCCPU-V, Q24DHCCPU-VG, Q24DHCCPU-LS, and Q26DHCCPU-LS

The side where the execution request from the master is processed and its execution

result is sent. The function that allows communication with the MODBUS compatible slave device as the

master of MODBUS. The function that allows communication with the MODBUS compatible master device as the

slave of MODBUS. The message used to give a function execution request to the slave In the MODBUS

protocol, a function execution request is given from the master to the slave.

A function execution request cannot be given from the slave to the master.

Abbreviation of the connected communication targets (devices corresponding to personal

computers, other QJ71MB91 MODBUS interface modules, MODBUS protocols) for data

communication.

Generic term for the following:

Microsoft Windows 7 Starter Operating System,

Microsoft Windows 7 Home Premium Operating System,

Microsoft Windows 7 Professional Operating System,

Microsoft Windows 7 Ultimate Operating System,

Microsoft Windows 7 Enterprise Operating System

A - 15

General term/Abbreviation Description

Generic term for the following:

Windows Vista

Windows XP

Microsoft Windows

Microsoft Windows Generic term for the following:

Microsoft Windows XP Professional Operating System,

Microsoft Windows XP Home Edition Operating System

Vista Home Basic Operating System,

Vista Home Premium Operating System,

Vista Business Operating System,

Vista Ultimate Operating System,

Vista Enterprise Operating System

MEANINGS AND DEFINITIONS OF TERM

The following explains the meanings and definitions of the terms used in this manual.

Ter m Description

MODBUS protocol

MODBUS device Device used for communication using the MODBUS protocol

Sequence program

Device memory

Listen only mode Mode detaching the slave station from the circuit.

Protocol used on an open MODBUS network which performs master-slave communications

over a serial bus or TCP/IP

Programming system devised to make a contact type sequence compatible with the

programmable controller language as-is. Draw two vertical control buses and describe

contacts, etc.

between the buses to perform programming. Memory provided for the programmable controller CPU to record the data handled in

sequence program operation.

PRODUCT CONFIGURATION

The following indicates the product configuration of the QJ71MB91 MODBUS interface module.

Model Product name Quantity

QJ71MB91 MODBUS interface module 1

QJ71MB91

SW1D5C-QMBU-E GX Configurator-MB Version 1 (1-license product) (CD-ROM) 1 SW1D5C-QMBU-EA GX Configurator-MB Version 1 (Multiple-license product) (CD-ROM) 1

Terminal resistor 330 1/4 W (for RS-422 communication) 2 Terminal resistor 110 1/2 W (for RS-485 communication) 2

A - 16

MODBUS slave device (Third party sensor, etc)

MODBUS slave device (Third party programmable controller)

Device memory

MODBUS slave device (Third party remote I/O, etc)

Holding register

RS-485

Programmable controller CPU

Device memory

Auto Refresh

QJ71MB91 (Master function)

Read Read

Read

Write

Buffer memory

Automatically issues the MODBUS device read/write request message to Slave.

OVERVIEW

CHAPTER1 OVERVIEW

This manual explains the specifications, functions, programming, and troubleshooting of the MELSEC-Q series QJ71MB91 MODBUS interface module (hereinafter referred to as QJ71MB91). The QJ71MB91 is used when a MELSEC-Q series programmable controller is connected to the MODBUS protocol system.

1.1 Features

OVERVIEW

SYSTEM

CONFIGURATION

(1) Supporting the master function of MODBUS communication

The QJ71MB91 supports the master function of the MODBUS communication, which is an open network system for factory automation, and thereby is compatible with various MODBUS slave devices (hereinafter referred to as slave) of other manufacturers. The master function includes the following two functions.

(a) Automatic communication function

By setting the automatic communication parameters, MODBUS device data can be automatically read from or written to the slaves at the specified intervals using

the QJ71MB91 buffer memory. Data can be transferred between the QJ71MB91 buffer memory and programmable controller CPU device memory by making the auto refresh setting with the utility package (GX Configurator-MB) or by accessing any intelligent function module device with a sequence program.

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Figure 1.1 Communication using the automatic communication function

* 1 The MODBUS device is defined as a device area of the slave where data can be read/written in

response to a request from the master.

1.1 Features

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

1 - 1

[Z.MBRW ]

Command

QJ71MB91

(Master function)

400500

Programmable controller CPU

Device memory

1234H

Request message (Read request for holding register 400500)

Response message (Holding register 400500 = 1234H)

1234H

Holding register

MODBUS Slave device

RS-232, RS-422 or RS-485

OVERVIEW

(b) Communication using dedicated instruction

Dedicated instructions can be used to make communication from sequence programs at any timing.

The following dedicated instructions are available for the QJ71MB91. ( CHAPTER 10)

1) MBRW instruction Reads or writes MODBUS device data from or to a slave. This enables reading slave data to the programmable controller CPU device memory or writing programmable controller CPU data to slaves.

2) MBREQ instruction The user-determined request message format (function code + data unit) can be issued to the slaves.

Figure 1.2 Communication using dedicated instruction

1 - 2

1.1 Features

D300

D299

400499

D300

400500

D301

400501

1234H

Device memory

Device

Programmable controller CPU

No sequence program required

MODBUS device assignment parameter

QJ71MB91 (Slave function)

MODBUS device

RS-232, RS-422 or RS-485

Request message (Write 1234H to holding register 400500)

MODBUS Master device

OVERVIEW

(2) Supporting the slave function of MODBUS communication

The QJ71MB91 supports the slave function of the MODBUS communication, which is an open network system for factory automation, and thereby is compatible with various MODBUS master devices (hereinafter referred to as master) of other manufacturers. The slave function includes the following two functions.

(a) Automatic response function

The QJ71MB91 can automatically respond to a request message received from the master. Any sequence program for the slave function is not needed.

(b) MODBUS device assignment function

Using MODBUS device assignment parameters, the MODBUS devices are correlated with the programmable controller CPU device memory. This enables direct access from the master to the programmable controller CPU device memory. Supporting the MODBUS devices of large capacity, the QJ71MB91 allows all device memories of the programmable controller CPU to be assigned.

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

Figure 1.3 MODBUS device assignment function

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

PARAMETER SETTING

1.1 Features

UTILITY PACKAGE

(GX Configurator-MB)

1 - 3

OVERVIEW

(3) Link operation function

The master connected to the CH1 side (RS-232) can communicate with multiple slaves connected to the CH2 side (RS-422/485) via the QJ71MB91. This function allows the MODBUS master device with RS-232 interface (for one-onone communication) to communicate with multiple MODBUS slave devices.

The request message/response message can be relayed between channel 1 and 2.

Request message

RS-232

Response Message

MODBUS master device (Third party programmable controller)

RS-485

Response Message

Request message

MODBUS slave device (Third party remote I/O, etc)

Figure 1.4 Communication using the link operation function

MODBUS slave device (Third party sensor, etc)

(4) Supporting high-speed communication of 115200 bps.

The total transmission speed of up to 115200bps is available for Channel 1 and 2.

(5) Easy setting by GX Configurator-MB

GX Configurator-MB, which is separately available, allows easy configuration of the QJ71MB91. It can reduce programing steps for sequence programs, and the setting and operating states of each module can be checked easily. Therefore, GX Configurator-MB is recommended to be used for the QJ71MB91. By setting various parameters in GX Configurator-MB, the QJ71MB91 can communicate without creating sequence programs.

1 - 4

1.1 Features

Remark

SYSTEM CONFIGURATION

CHAPTER2 SYSTEM CONFIGURATION

This chapter explains the system configuration of the QJ71MB91.

OVERVIEW

2.1 Applicable Systems

This section describes the applicable systems.

(1) Applicable modules and base units, and number of mountable modules

(a) When mounted with a CPU module

Refer to the user’s manual of the CPU module used. Observe the following:

• A shortage of the power capacity may result depending on the combination of mounted modules or the number of mounted modules. When mounting modules, consider the power capacity. If the power is insufficient, change the combination of modules.

• Mount modules so that the total number of I/O points does not exceed the point range of the CPU module. Modules can be mounted in any slot within the applicable range.

When mounted with a C Controller module, refer to the user’s manual of the C Controller module used.

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

(b) When mounted on a MELSECNET/H remote I/O station

Refer to the following.

Q Corresponding MELSECNET/H Network System Reference Manual

(Remote I/O network)

Refer to the following.

MELSEC iQ-R Module Configuration Manual

(2) Support of the multiple CPU system

Please refer to the following manual before using the QJ71MB91 in the multiple CPU system.

QCPU User's Manual (Multiple CPU System)

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

2.1 Applicable Systems

UTILITY PACKAGE

(GX Configurator-MB)

2 - 1

SYSTEM CONFIGURATION

(3) Supported software package

Relation between the system containing the QJ71MB91 and software package is shown in the following table. GX Developer or GX Works2 is required to start up the system in which the QJ71MB91 is used.

Table2.1 Supported software package

Software version

Item

GX Developer GX Configurator-MB GX Works2

Q00J/Q00/Q01CPU

Q02/Q02H/Q06H/

Q12H/Q25HCPU

Q02PH/Q06PHCPU

Q12PH/Q25PHCPU

Q12PRH/Q25PRHCPU Redundant system

Q00UJ/Q00U/Q01UCPU

Q02U/Q03UD/

Q04UDH/Q06UDHCPU

Q10UDH/Q20UDHCPU

Q13UDH/Q26UDHCPU

Single CPU system Version 7 or later

Multiple CPU system Version 8 or later

Single CPU system Version 4 or later

Multiple CPU system Version 6 or later

Single CPU system

Multiple CPU system

Single CPU system

Multiple CPU system

Single CPU system

Multiple CPU system

Single CPU system

Multiple CPU system

Single CPU system

Multiple CPU system

Single CPU system

Multiple CPU system

Version 8.68W or later

Version 7.10L or later

Version 8.18U or later

Version 8.76E or later

Version 8.48A or later

Version 8.76E or later

Version 8.62Q or later

Version 1.05F or later

Refer to the GX Works2

Version 1 Operating

Manual (Common).

Version 1.08J or later

Q03UDE/Q04UDEH/Q06UDEH/

Q13UDEH/Q26UDEHCPU

Q10UDEH/Q20UDEHCPU

CPU module other than those

listed above

When mounted to MELSECNET/H remote I/O station Version 6.01B or later Version 1.05F or later

2 - 2

2.1 Applicable Systems

Single CPU system

Version 8.68W or later

Multiple CPU system

Single CPU system

Version 8.76E or later

Multiple CPU system

Single CPU system

N/A N/A

Multiple CPU system

* 1 To use an extension base unit, use 8.45X or later.

SYSTEM CONFIGURATION

2.2 Network Configuration

The following shows MODBUS network configuration examples using the QJ71MB91.

Master/Slave Line Used

Table2.2 Network configuration using QJ71MB91

QJ71MB91

System Configuration Reference

OVERVIEW

Master

Slave

Master/Slave

RS-232

RS-422/485 This section (1) (b)

RS-232, RS-422/485 This section (1) (c)

RS-485 1:n This section (1) (d)

RS-232

RS-422/485 This section (2) (b)

RS-232, RS-422/485 This section (2) (c)

RS-485 1:n This section (2) (d)

RS-232, RS-485

(with link operation

function)

RS-232 (Master),

RS-485 (Slave)

RS-232 (Slave)

RS-485 (Master)

1:1

1:n This section (2) (e)

1:n

This section (1) (a)

This section (2) (a)

This section (3) (a)

This section (3) (b)

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

2.2 Network Configuration

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

2 - 3

RS-232

QJ71MB91 (Master function)

MODBUS slave device

RS-485

QJ71MB91 (Master function)

MODBUS slave device

SYSTEM CONFIGURATION

(1) Using the QJ71MB91 as a master station

(a) Connecting to a slave station (1:1) with a RS-232 line

Figure 2.1 Connecting to a slave station (1:1) with a RS-232 line

(b) Connecting to a slave station (1:1) with a RS-422/485 line

QJ71MB91 (Master function)

MODBUS slave device

RS-422/485

Figure 2.2 Connecting to a slave station with a RS-422/485 line

QJ71MB91 (Master function)

MODBUS slave device

RS-232

MODBUS slave device

RS-422/485

Figure 2.3 Connecting to slave stations (1:1) with RS-232 and RS-422/485 lines

(d) Connecting to slave stations (1:n)

2 - 4

2.2 Network Configuration

Figure 2.4 Connecting to slave stations (1:n)

RS-232

MODBUS master device

RS-422/485

QJ71MB91 (Slave function)

SYSTEM CONFIGURATION

(2) Using the QJ71MB91 as a slave station

(a) Connecting to a master station (1:1) with a RS-232 line

MODBUS master device

RS-232

Figure 2.5 Connecting to a master station (1:1) with a RS-232 line

QJ71MB91 (Slave function)

(b) Connecting to a master station (1:1) with a RS-422/485 line

QJ71MB91 (Slave function)

MODBUS master device

RS-422/485

Figure 2.6 Connecting to a master station (1:1) with a RS-422/485 line

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 2.7 Connecting to master stations with RS-232 and RS-422/485 lines

* 1 The same station number is used for both RS-232 and RS-422/485 interfaces.

(d) Connecting to a master station (1:n)

MODBUS master device

RS-485

MODBUS slave device

QJ71MB91 (Slave function)

Figure 2.8 Connecting to a master station (1:n)

MODBUS slave device

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

2.2 Network Configuration

2 - 5

RS-485

RS-232

MODBUS master device QJ71MB91 (Slave function)

MODBUS slave device

QJ71MB91

RS-485

RS-232

MODBUS

MODBUS master device

(Master function)

(Slave function)

slave device

MODBUS slave device

MODBUS master device

MODBUS slave device

RS-232

QJ71MB91

(Slave function)

(Master function)

RS-485

SYSTEM CONFIGURATION

(e) Connecting to a master station (1:n) with the link operation function

Figure 2.9 Connecting to a master station (1:n) with the link operation function

(3) Connecting master and slave stations separately through each interface

(a) Using the RS-232 interface as the master station and the RS-422/485 interface as

the slave station

Figure 2.10 Using the RS-232 interface as the master station and the RS-422/485

(b) Using the RS-232 interface as the slave station and the RS-422/485 interface as

the master station

Figure 2.11 Using the RS-232 interface as the slave station and the RS-422/485 interface

interface as the slave station

as the master station

2 - 6

2.2 Network Configuration

SYSTEM CONFIGURATION

2.3 Precautions for System Configuration

(1) When used with a Redundant CPU

For precautions, refer to the following.

QnPRHCPU User's Manual (Redundant System)

(2) When used with a C Controller module

For precautions, refer to the following.

User’s manual of the C Controller module used

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

2.3 Precautions for System Configuration

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

2 - 7

10021

Relevant regulation standards

Function version

Serial number (first five digits)

Serial No.

Function version

SYSTEM CONFIGURATION

2.4 How to Check the Function Version/Software Version

Check the function version and serial No. of the QJ71MB91and the GX Configurator-MB software version by the following methods.

(1) Checking the version and serial No. of the QJ71MB91 functions

The serial No. and function version of the QJ71MB91 can be confirmed on the rating plate and GX Developer's system monitor.

(a) Confirming the serial number on the rating plate

The rating plate is situated on the side face of the QJ71MB91.

Figure 2.12 Rating plate

(b) Checking on the front of the module

The serial No. and function version on the rating plate are also indicated on the front of the module (lower part).

2 - 8

2.4 How to Check the Function Version/Software Version

Figure 2.13 Front face of QJ71MB91

POINT

SYSTEM CONFIGURATION

To display the system monitor, select [Diagnostics] [System monitor]

Product Inf. List

1) Production number display Since the QJ71MB91 does not support the production number display, "-" is displayed.

button of GX Developer.

Function version

Serial No. Production number

Figure 2.14 Product information list

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

The serial No. displayed in the Product Information List of GX Developer may be different from the one on the rating plate and the front of the module.

• The serial No. on the rating plate and the front of the module indicates the management information of the product.

• The serial No. in the Product Information List of GX Developer indicates the functional information on the product, which is updated when a new function is added.

2.4 How to Check the Function Version/Software Version

2 - 9

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

Software version

SYSTEM CONFIGURATION

(2) Checking the software version of GX Configurator-MB

The software version of GX Configurator-MB can be checked GX Developer’s "Product information" screen.

[Operating Procedure] GX Developer [Help] [Product information]

Figure 2.15 Product information

2 - 10

2.4 How to Check the Function Version/Software Version

SPECIFICATIONS

CHAPTER3 SPECIFICATIONS

This chapter explains the performance specifications of the QJ71MB91, interface specifications, I/O signals for communications with programmable controller CPU, and buffer memory. Please refer to the following manual for general specifications.

QCPU User's Manual (Hardware Design, Maintenance and Inspection)

3.1 Performance Specifications

OVERVIEW

SYSTEM

CONFIGURATION

Transmission

specifications

This section provides the performance specifications of QJ71MB91.

Table3.1 Performance specifications

Item Specifications Reference

Number of interfaces

Transmission speed Section 6.6

Transmission

distance

(Overall distance)

Automatic

communication

function

RS-232 Max. 15m (49.2 ft.) -

RS-422/485 Max. 1200m (4592.4 ft.) (Overall distance) -

Number of slaves

Function (for send) 7 functions Section 7.2.1

Input area size 4k words

Output area size 4k words

RS-232 1 channel, RS-422/485 1 channel

300 600 1200 2400

4800 9600 14400 19200

28800 38400 57600 115200 (bps)

Communication is available with total transmission

speed of two interfaces within 115200bps.

32 per channel -

Section 3.5.1

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Master

function

Communication

by dedicated

instructions

(MBRW, MBREQ)

Number of instructions that

can be executed

concurrently

Function (for send)

Input area size Max. 253 bytes per instruction

Output area size Max. 253 bytes per instruction

MBREQ instruction: 19 functions

1 per channel

MBRW instruction: 9 functions

(Continued on next page)

3.1 Performance Specifications

CHAPTER 10

3 - 1

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

Table3.1 Performance specifications (Continued)

Item Specifications Reference

Automatic

response function

MODBUS Device

Slave function

Number of occupied I/O points 32 points -

5VDC internal current consumption 0.31A -

External dimensions

Weight 0.20kg -

size

No. of simultaneously acceptable request

messages

Station No. 1 to 247 Section 6.6

Function (for receive) 17 functions CHAPTER 4

Coil 64k points

Input 64k points

Input register 64k points

Holding register 64k points

Extended file register Max. 4086k points

1 request per channel -

98 (3.86 in.) (H) 27.4 (1.08 in.) (W) 90 (3.54 in.)

(D) [mm]

* 1 Indicates the maximum number of slaves that can be communication targets. * 2 Indicates the maximum number of dedicated instructions that can be executed simultaneously from

a sequence program.

Section 7.3.1

Appendix 4

3 - 2

3.1 Performance Specifications

SPECIFICATIONS

3.2 RS-232 Interface Specification

This section explains RS-232 interface specifications.

3.2.1 RS-232 connector specification

This section provides the specifications of RS-232 connector that is connected to a target device.

OVERVIEW

number

2 RD (RXD) Reception data

Signal code Signal name

(Use

prohibited)

(Use

prohibited)

QJ71MB91 Target device

Signal direction

SYSTEM

CONFIGURATION

3SD (TXD)

5 SG (GND) Signal ground

(Use

prohibited)

(Use

prohibited)

(Use

prohibited)

Transmission

data

(Use

prohibited)

(Use

prohibited)

Output for

cable

disconnection

detection

Input for cable

disconnection

detection

(Use

prohibited)

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Figure 3.1 RS-232 connector specification

* 1 Connect Pin 8 to Pin 7.

Without connecting Pin 7 and 8, Pin 8 turns off and the CS signal may turn off (error code: 7403

(1) Descriptions of control signals

The following explains control signals. (The pin number of the connector is indicated within the brackets.)

(a) RD signal (2)

Signal for receiving data.

(b) SD signal (3)

Signal for sending data.

3.2 RS-232 Interface Specification

3.2.1 RS-232 connector specification

H).

3 - 3

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

(2) ON/OFF status of each signal

The ON and OFF statuses of a signal are indicated below.

(Output side) (Input side)

ON ......................... 5V to 15VDC, 3V to 15VDC

OFF ......................... -5V to -15VDC, -3V to -15VDC

(3) Interface connector

For QJ71MB91 RS-232 interface connector, use a 9-pin D sub (female) screw type connector. Use metric screws.

3 - 4

3.2 RS-232 Interface Specification

3.2.1 RS-232 connector specification

SPECIFICATIONS

3.2.2 RS-232 cable specification

The RS-232 cable should be based on RS-232 standards and used within 15m(49.2ft).

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

3.2 RS-232 Interface Specification

3.2.2 RS-232 cable specification

3 - 5

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SDA

SDB

RDA

RDB

(FG)

SPECIFICATIONS

3.3 RS-422/485 Interface Specification

This section explains RS-422/485 interface specifications.

3.3.1 RS-422/485 terminal block specification

This section provides the specifications of RS-422/485 terminal block that is connected to a target device.

Signal

code

SDA Transmission data (+)

SDB Transmission data (-)

RDA Reception data (+)

RDB Reception data (-)

SG Signal ground

FG Frame ground

Figure 3.2 RS-422/485 terminal block specifications

Signal name

(1) The following explains control signals.

(a) SDA, SDB signal

Signal for QJ71MB91 to send data to a target device

(b) RDA, RDB signal

Signal for QJ71MB91 to receive data from a target device

Signal direction

QJ71MB91 Target device

3 - 6

(2) Terminating resistor

Connect the terminating resistor according to Section 6.5.2.

3.3 RS-422/485 Interface Specification

3.3.1 RS-422/485 terminal block specification

SPECIFICATIONS

3.3.2 RS-422/485 cable specification

This section explains the specifications of RS-422/485 cable.

(1) RS-422/485 cable to be used

The RS-422/485 cable should meet the following specifications and used within 1200m(4592.4ft).

(2) When making a 1:n connection

When connecting to multiple devices (1:n), ensure that the overall distance is within 1200 m(4592.4ft).

(3) RS-422/485 cable specifications

Table3.2 RS-422/485 cable specifications

Item Description

Cable type Shielded cable

Number of pairs 3P

Conductor resistance (20°C) 88.0/km or less

Insulation resistance 10000M•km or more

Dielectric withstand voltage 500VDC, 1 minute

Electrostatic capacitance (1 kHz) 60nF/km or less by an average

Characteristic impedance (100 kHz) 110±10

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Recommended conductor size

0.2 mm

to 0.75 mm

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

3.3 RS-422/485 Interface Specification

3.3.2 RS-422/485 cable specification

3 - 7

UTILITY PACKAGE

(GX Configurator-MB)

POINT

Remark

Receive data

Target device

Terminating resistor

RDA

RDB

SPECIFICATIONS

3.3.3 Precautions when transferring data using RS-422/485 line

Note the following points when performing data communication with a target device through the RS-422/485 interface of QJ71MB91. For the target device side, pay attention to the following when sending/receiving data.

(1) Preventive measures against faulty data reception on the target device

side

If the target device receives error data, install a pull-up or pull-down resistor to the target device as shown below.

Installing a pull-up or pull-down resistor (resistance value: approx. 4.7 k , 1/4 W) can prevent the reception of error data.

Figure 3.3 Preventive measures against faulty data reception

Error data will not be received if a pull-up or pull-down resistor is connected on the target device side.

The case where any pull-up or pull-down resistor is not connected on the target device is described below. When any station is not performing transmission, the transmission line is in a high impedance status and the line status is not stable due to noises, and the target device may receive error data. In such a case, parity or framing error may have occurred. Skip data reading for error data.

3 - 8

3.3 RS-422/485 Interface Specification

3.3.3 Precautions when transferring data using RS-422/485 line

Data

(Output control input)

Target device side

QJ71MB91 side

Outputs a mark with 2 characters or more

Data transmission time range

H/W gate OFF time (Refer to explanation above) OFF time range of output control input (High impedance status)

QJ71MB91 can receive data.

ON time range of output control input (Low impedance status)

QJ71MB91 can send data.

SPECIFICATIONS

(2) RS-422/485 interface operation

(a) RS-422/485 interface configuration

For RS-422/485 interface, the configuration of driver (send)/receiver (receive) component of the QJ71MB91 is as shown in the following diagram.

SDR

SDB

Output Control Input (*

RDA

RDB

Figure 3.4 RS-422/485 interface configuration

* 1 The "output control input" (also referred to as send gate) of the driver (send) component

determines whether to output data externally from SDA, SDB.

Driver

Receiver

Send data

Receive data

OVERVIEW

)

SYSTEM

CONFIGURATION

(b) RS-422/485 interface operation

When the "output control input" in the above figure is ON, the impedance status is low (data transmittable). In addition, when the "output control input" is OFF, the impedance status is high (data not transmitted).

• Transmission start timing After releasing the high impedance status indicated in above (a) and (b), and outputting two or more character data during data transmission, output the actual data.

• Transmission process complete timing Data transmission time for data of 1 bit or less is required as the H/W gate OFF time to complete the transmission process (high impedance status) after finishing data transmission. (Transmission speed set in the QJ71MB91 is targeted.)

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

SPECIFICATIONS

FUNCTIONS

FUNCTION

SETTINGS

3.3.3 Precautions when transferring data using RS-422/485 line

Figure 3.5 Transmission process complete timing

3.3 RS-422/485 Interface Specification

3 - 9

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

3.4 I/O Signals for Programmable Controller CPU

This section explains the I/O signals for the programmable controller CPU of QJ71MB91.

3.4.1 I/O signal list

This section explains the I/O signals for the QJ71MB91. The following I/O signal assignment is based on the case where the start I/O No. of the QJ71MB91 is "0000" (installed to slot 0 of the main base unit). Device X represents an input signal from the QJ71MB91 to the programmable controller CPU. Device Y means an output signal from the programmable controller CPU to the QJ71MB91. The I/O signals for programmable controller CPU are listed below. Refer to the reference sections for the details of each signal.

Table3.3 I/O signal list

Signal direction QJ71MB91 Programmable controller CPU Signal direction Programmable controller CPU QJ71MB91

Device No. Signal name Reference Device No. Signal name Reference

Module READY

X2 Y2

X3 Y3

ON : Accessible

OFF : Inaccessible

Use prohibited -

CH1 Automatic communication

parameter setting, normally completed

ON : Normally completed

OFF : -

CH1 Automatic communication

parameter setting, error completed

ON : Error completed

OFF : -

CH1 Automatic communication

operation status

ON : Operating

OFF : Stopped

Section

11. 1

Section

5.2.1,

9.1.1

Y5 Use prohibited -

Use prohibited -

CH1 Automatic communication parameter

setting request/automatic communication

start request

ON : Being requested

OFF : Not requested

CH1 Automatic communication stop

request

ON : Being requested

OFF : Not requested

Section

5.2.1,

9.1.1

Section

5.2.1

3 - 10

CH1 Automatic communication error

status

ON : Error occurred

OFF : No error

* 1 Turns ON when the QJ71MB91 is ready after the programmable controller is turned from OFF to

ON or after the programmable controller CPU is reset.

Section

5.2.1

3.4 I/O Signals for Programmable Controller CPU

3.4.1 I/O signal list

Y7 Use prohibited -

(Continued on next page)

Signal direction QJ71MB91 Programmable controller CPU Signal direction Programmable controller CPU QJ71MB91

SPECIFICATIONS

Table3.3 I/O signal list (Continued)

Device No. Signal name Reference Device No. Signal name Reference

MODBUS device assignment

XB Use prohibited - YB

parameter setting, normally completed

ON : Normally completed

OFF : -

MODBUS device assignment

parameter setting, error completed

ON : Error completed

OFF : -

MODBUS device assignment

parameter setting existence

ON : Parameters set

OFF: No parameters set

CH2 Automatic communication

parameter setting, normally completed

ON : Normally completed

OFF : -

CH2 Automatic communication

parameter setting, error completed

ON : Error completed

OFF : -

Section

9.1.2

Section

5.2.1,

9.1.1

YD Use prohibited -

MODBUS device assignment parameter

setting request

ON : Being requested

OFF : Not requested

Use prohibited -

CH2 Automatic communication parameter

setting request/automatic communication

start request

ON : Being requested

OFF : Not requested

Section

9.1.2

Section

5.2.1,

9.1.1

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

CH2 Automatic communication

operation status

ON : Operating

OFF : Stopped

CH2 Automatic communication error

status

ON : Error occurred

OFF : No error

Section

5.2.1

CH2 Automatic communication stop request

YF Use prohibited -

ON : Being requested

OFF : Not requested

Section

5.2.1

(Continued on next page)

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

3.4 I/O Signals for Programmable Controller CPU

3.4.1 I/O signal list

3 - 11

UTILITY PACKAGE

(GX Configurator-MB)

POINT

Signal direction QJ71MB91 Programmable controller CPU Signal direction Programmable controller CPU QJ71MB91

Device No. Signal name Reference Device No. Signal name Reference

SPECIFICATIONS

Intelligent function module switch

X10

setting change status

ON : Setting being changed

OFF : Setting not changed

Table3.3 I/O signal list (Continued)

Section

10.4

Y10

X11

X12 - Y12

X13 - Y13

X14 - Y14

X15 - Y15

X16 - Y16

X17 - Y17

X18 - Y18

X19 - Y19

X1A - Y1A

X1B

X1C

Use prohibited

CH Common/CH1 Error

ON : Error occurred

OFF : No error

CH2 Error

ON : Error occurred

OFF : No error

- Y11

Y1B

Section

11. 2

Y1C

Use prohibited -

CH Common/CH1 Error clear request

ON : Being requested

OFF : Not requested

CH2 Error clear request

ON : Being requested

OFF : Not requested

Section

11. 5

X1D

Use prohibited -

X1E Y1E

X1F

Watch dog timer error

ON : Module error occurred

OFF : Module operating normally

Section

11. 1

Y1D

Y1F

Do not output (turn ON) any "Use prohibited" signal among I/O signals for programmable controller CPU. Doing so may cause the programmable controller system to malfunction.

Use prohibited -

3 - 12

3.4 I/O Signals for Programmable Controller CPU

3.4.1 I/O signal list

SPECIFICATIONS

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

The buffer memory list is shown below.

Table3.4 Buffer memory list

OVERVIEW

Address Application Name

0000H to 0001

(0 to 1)

0002H

(2)

0003H

(3)

0004

(4)

0005H

(5)

0006H

(6)

0007

(7)

0008

(8)

0009H

(9)

000A

(10)

000B

(11)

System area (use prohibited) - - - -

CH1 side error response code storage area 0

System area (use prohibited) - - - -

Error code

Status

storage

area

Setting

area

Detailed

LED status

Detailed

LED clear

request

Setting

error status

read device

CH2 side error response code storage area 0

System area (use prohibited) - - - -

CH1 side detailed LED status storage area 0

CH2 side detailed LED status storage area 0

CH1 side detailed LED clear request storage

area

CH2 side detailed LED clear request storage

area

Device code F000

Head device number 0

Initial value

Read/

Write

(*1)

H R

R/W

H R/W

R/W

Initial

setting

(*2)

Reference

Section

11. 4.2

Section

11. 4.2

Section

11. 2

Section

11. 5

Section

7.3.4

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

000CH

(12)

System area (use prohibited) - - - -

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Continued on next page)

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

3 - 13

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

000DH

(13)

000E

(14)

000F

(15)

0010H to 01FFH

(16 to 511)

0200H to 0201

(512 to 513)

0202

(514)

0203H

(515)

0204

(516)

Setting area

System area (use prohibited) - - - -

CPU response monitoring timer value

Set time = set value 500ms

Access target (when mounted to

MELSECNET/H remote I/O station)

Allocated error status area 0

Setting parameter existence 0

Target station No. 1

Request interval timer value

Set time = set value 10ms

Response monitoring timer value/Broadcast

delay value

Set time = set value 10ms

Initial value

Read/

Write

H R/W

(*1)

R/W

Initial

setting

(*2)

Reference

Section

7.3.6

Section

7.3.5

Section

7.3.4

0205

(517)

0206

(518)

0207H

(519)

0208

(520)

0209

(521)

020AH

(522)

020B

(523)

Automatic

communication

parameter

CH1 Automatic

communication

parameter 1

Type specification of the target MODBUS

device

Head buffer memory address 0000

Read

setting

Target MODBUS device head

number

Access points 0

Head buffer memory address 0000

Write

setting

Target MODBUS device head

number

Access points 0

0000

H R/W

R/W

Section 7.2

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Continued on next page)

3 - 14

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

CH1 Automatic

020CH to 037F

(524 to 895)

0380H to 04FFH

(896 to 1279)

0500H to 08FF

(1280 to 2303)

0900

(2304)

0901H

(2305)

0902

(2306)

0903

(2307)

Automatic

communication

parameter

System area (use prohibited) - - - -

MODBUS

device

assignment

parameter

communication

parameter 2 to

CH2 Automatic

communication

parameter 1 to

Coil

assignment 1

(Same as CH1 Automatic communication parameter 1)

Device code 0

Head device number 0

Head coil number 0

Assignment points 0

Initial value

Read/

Write

(*1)

R/W

H R/W

R/W

Initial

setting

(*2)

Reference

Section

7.2

Section

7.3.1

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

0904H to 093FH

(2308 to 2367)

Coil

assignment 2

to 16

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Same as in Coil assignment 1)

(Continued on next page)

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

3 - 15

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0940

(2368)

0941

(2369)

0942H

(2370)

0943H

(2371)

0944H to 097F

(2372 to 2431)

0980H

(2432)

0981H

(2433)

0982

(2434)

MODBUS

device

assignment

parameter

Input

assignment

Input

assignment

2 to 16

Input

assignment

Device code 0

Head device number 0

Head input number 0

Assignment points 0

(Same as input assignment 1)

Device code 0

Head device number 0

Head input register number 0

Initial value

Read/

Write

(*1)

R/W

H R/W

R/W

Initial

setting

(*2)

Reference

Section

7.3.1

0983

(2435)

0984H to 09BFH

(2436 to 2495)

Assignment points 0

Input

assignment

2 to 16

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

(Same as in input register assignment 1)

disabled. R: Readable W: Writable

: Setting enabled : Setting disabled

R/W

(Continued on next page)

3 - 16

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

09C0

(2496)

09C1

(2497)

09C2

(2498)

09C3

(2499)

09C4H to 09FF

(2500 to 2559)

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

MODBUS

device

assignment

parameter

Holding

assignment

Holding

assignment

2 to 16

Device code 0

Head device number 0

Head holding register number 0

Assignment points 0

(Same as in holding register assignment 1)

Initial value

Read/

Write

(*1)

R/W

Initial

setting

(*2)

Reference

Section

7.3.1

OVERVIEW

SYSTEM

CONFIGURATION

0A00H to 0BFF

(2560 to 3071)

0C00

(3072)

0C01

(3073)

0C02

(3074)

0C03

(3075)

0C04

(3076)

0C05

(3077)

0C06

(3078)

0C07

(3079)

0C08

(3080)

0C09

(3081)

System area (use prohibited) - - - -

Setting

status

Operating

status

Intelligent

function

module

switch

setting

status

Module

status

Intelligent

function

module

switch

operating

status

Switch 1: CH1 operation mode setting status

Switch 2: CH1 transmission setting status R

Switch 3: CH2 operation mode setting status R

Switch 4: CH2 transmission setting status R

Switch 5: CH1/CH2 Station No. setting status R

LED ON status 0

Switch 1: CH1 operation mode status

Switch 2: CH1 transmission status R

Switch 3: CH2 operation mode status R

Switch 4: CH2 transmission status R

Intelligent

function

module

switch

status

Intelligent

function

module

switch

status

Section

6.6, 11.2

Section

6.3, 11.2

Section

10.4

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

SPECIFICATIONS

FUNCTIONS

FUNCTION

SETTINGS

0C0A

(3082)

0C0BH to 0C12

(3083 to 3090)

Switch 5: CH1/CH2 Station No. status R

System area (use prohibited) - - - -

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

PARAMETER SETTING

(Continued on next page)

UTILITY PACKAGE

(GX Configurator-MB)

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

3 - 17

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0C13

(3091)

0C14

(3092)

0C15H

(3093)

0C16

(3094)

0C17

(3095)

0C18H

(3096)

0C19

(3097)

0C1AH to 0C1F

(3098 to 3103)

Operating

status

Parameter

error

information

System area (use prohibited) - - - -

MODBUS device assignment parameter error

code storage area

MODBUS

device

assignment

parameter

setting result

storage area

CH1 Automatic communication parameter error

code storage area

CH1 Automatic communication parameter setting

result storage area

CH2 Automatic communication parameter error

code storage area

CH2 Automatic communication parameter setting

result storage area

Error, device type 0

Error, assigned group No. 0

Initial value

H R

Read/

Write

(*1)

Initial

setting

(*2)

Reference

Section

11. 4.1

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Continued on next page)

3 - 18

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0C20H to 0C21

(3104 to 3105)

0C22H to 0C23H

(3106 to 3107)

0C24H to 0C27

(3108 to 3111)

0C28H to 0C47

(3112 to 3143)

0C48H to 0C67H

(3144 to 3175)

0C68H to 0CA7

(3176 to 3239)

0CA8H to 0CA9

(3240 to 3241)

0CAAH to 0CABH

(3242 to 3243)

Operating

status

Communication

condition

monitor area

CH1 Automatic communication operation

status storage area

(Parameters 1 to 32)

CH2 Automatic communication operation

status storage area

(Parameters 1 to 32)

System area (use prohibited) - - - -

CH1 Automatic communication error code

storage area

(Parameters 1 to 32)

CH2 Automatic communication error code

storage area

(Parameters 1 to 32)

System area (use prohibited) - - - -

CH1 Automatic communication setting status

storage area

(Parameters 1 to 32)

CH2 Automatic communication setting status

storage area

(Parameters 1 to 32)

Initial value

Read/

Write

(*1)

H R

Initial

setting

(*2)

Reference

OVERVIEW

Section

11. 4.1

SYSTEM

CONFIGURATION

Section

11. 4.1

SPECIFICATIONS

Section

11. 4.1

MODBUS STANDARD

FUNCTIONS

0CACH to 0CAF

(3244 to 3247)

0CB0H to 0CB1

(3248 to 3249)

0CB2H to 0CB3H

(3250 to 3251)

0CB4H to 0CFD

(3252 to 3325)

System area (use prohibited) - - - -

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

System area (use prohibited) - - - -

CH1 Automatic communication ready status

storage area

(Parameters 1 to 32)

CH2 Automatic communication ready status

storage area

(Parameters 1 to 32)

: Setting enabled : Setting disabled

R-

H R-

(Continued on next page)

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

Section

9.2.3

3 - 19

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0CFE

(3326)

0CFF

(3327)

0D00H

(3328)

0D01

(3329)

0D02

(3330)

0D03H

(3331)

0D04

(3332)

0D05H to 0D06

(3333 to 3334)

Operating

status

Error log

Number of errors occurred 0

Error log write pointer 0

Detailed error code 0

Exception code 0

Function code 0

Error log 1

CH 0

Station No. 0

System area (use prohibited) - - - -

Initial

value

Read/

Write

(*1)

H R

Initial

setting

Reference

(*2)

Section

11. 4.1

0D07H

(3335)

0D08H to 0DFFH

(3336 to 3583)

0E00H to 0EFF

(3584 to 3839)

Function 0

Error log

2 to 32

System area (use prohibited) - - - -

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Same as Error log 1)

H R

(Continued on next page)

Section

11. 4.1

Section

11. 4.1

3 - 20

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0F00

(3840)

0F01H

(3841)

0F02

(3842)

0F03

(3843)

0F04H

(3844)

0F05

(3845)

0F06

(3846)

0F07H

(3847)

Communication

status

CH1

Communication

status

Diagnostic

data for

Master/Slave

Bus message count 0

Bus communication error count 0

Character overrun error count 0

Message discard count 0

Data discard count 0

Failed transmission count 0

Slave message count 0

Slave no-response count 0

Initial value

Read/

Write

(*1)

H R

Initial

setting

(*2)

Reference

Section

11. 3

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

0F08

(3848)

0F09

(3849)

0F0AH

(3850)

0F0B

(3851)

0F0C

(3852)

0F0DH

(3853)

Diagnostic

data for Slave

Slave NAK count 0

Slave busy count 0

Exception error count 0

Communications event count 0

H R

MODBUS STANDARD

FUNCTIONS

Section

4.12

FUNCTION

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

2nd byte of end code 0A

Communications mode 0

H R

(Continued on next page)

Section

4.11.4

Section

4.11.5

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

3 - 21

UTILITY PACKAGE

(GX Configurator-MB)

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

0F0E

(3854)

0F0FH

(3855)

0F10

(3856)

0F11

(3857)

CH1

Diagnostic data

for Master

Communication

0F12H

status

(3858)

Communication

0F13H to 0F1E

(3859 to 3870)

0F1F

(3871)

status

System area (use prohibited) - - - -

Communication

event log (for

0F20H to 0F3FH

Slave)

(3872 to 3903)

Initial

value

Received exception error

count

No-response count 0

Broadcast count 0

Received NAK count 0

Received busy count 0

Communications event log

count

Communications event log

1 to 64

H R

Read/

Write

(*1)

Initial

setting

(*2)

Reference

Section

11. 3

Section

4.13

0F40H to 0F7F

(3904 to 3967)

0F80H to 0FFD

(3968 to 4093)

0FFEH

(4094)

0FFF

(4095)

Unit test result

CH2

Communication

status

(Same as CH1 communication status)

Section

4.13

System area (use prohibited) - - - -

Hardware test result 0

Self-loopback test result 0

H R

Section

6.4.1

Section

6.4.2

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

disabled. R: Readable W: Writable

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

: Setting enabled : Setting disabled

(Continued on next page)

3 - 22

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

SPECIFICATIONS

Table3.4 Buffer memory list (Continued)

Address Application Name

1000H to 1FFF

(4096 to 8191)

2000H to 2FFFH

(8192 to

12287)

3000H to 3FFF

(12288 to

16383)

4000H to 4FFF

(16384 to

20479)

5000H to 5FFFH

(20480 to

24575)

Automatic

communication function

buffer

User free area 0H R/W

* 1 Indicates whether the reading (Read)/writing (Write) from the sequence program is enabled or

* 2 Indicates whether setting on GX Configurator-MB is enabled or disabled.

CH1 Automatic communication function buffer input

area

CH2 Automatic communication function buffer input

area

CH1 Automatic communication function buffer output

area

CH2 Automatic communication function buffer output

area

disabled. R: Readable W: Writable

: Setting enabled : Setting disabled

Initial

value

H R

Read/

Write

(*1)

R/W

Initial

setting

(*2)

Reference

Section

5.2.1

Section

7.3.3

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

3 - 23

UTILITY PACKAGE

(GX Configurator-MB)

MODBUS STANDARD FUNCTIONS

CHAPTER4 MODBUS STANDARD FUNCTIONS

This chapter explains the MODBUS standard functions supported by the QJ71MB91. Using the MODBUS standard functions allows you to read/write to programmable controller CPU devices and to load the QJ71MB91 status into the master.

4.1 MODBUS Standard Function Support List

(1) MODBUS standard function support list

The following table indicates a list of the MODBUS standard functions supported by the QJ71MB91.

Table4.1 MODBUS standard function support list

Function

code

(Sub code)

01 - Read coils

02 - Read discrete inputs

03 - Read holding registers

04 - Read input registers

05 - Write single coil Writes a value (ON/OFF) to one coil. 1 point

06 - Write single register Writes a value to one holding register. 1 point

07 - Read exception status Reads error status. -

Sub-function

code

Function Description

Reads the status (ON/OFF) of one or

more coils.

Reads the status (ON/OFF) of one or

more inputs.

Reads the values of one or more

holding registers.

Reads the values of one or more input

registers.

Accessible

devices

per

message

1 to

2000 points

1 to

2000 points

1 to

125 points

1 to

125 points

Broadcast Reference

(Continued on next page)

Section

4.4

Section

4.5

Section

4.6

Section

4.7

Section

4.8

Section

4.9

Section

4.10

4 - 1

4.1 MODBUS Standard Function Support List

MODBUS STANDARD FUNCTIONS

Table4.1 MODBUS standard function support list (continued)

Function

code

(Sub code)

Sub-function

code

00 Return query data

04 Force listen only mode

Function Description

Restart communications

option

Return diagnostic

Change ASCII input

delimiter

Clear counters and

diagnostic register

Returns the contents of the request

message without change.

Used to check if the network or the

target device is operating normally.

(Loopback test)

Initializes the communication port of the

receiving channel side and restarts the

slave function. (Clears counters such

as the message count.)

Returns to the online mode when it is in

the listen only mode.

Reads out the detailed LED status of

the QJ71MB91 to the master.

Changes the 2nd byte (LF(0A

end code in the ASCII mode to a

specified data.

Places a slave into the offline mode.

Used when disconnecting a slave from

the network.

Clears counters (e.g. message count).

Also, clears the diagnostic register and

the error of the channel where the

request message has been received.

H)) of the

Accessible

devices

per

message

Broadcast Reference

Section

4.11.1

Section

4.11.2

Section

4.11.3

Section

4.11.4

Section

4.11.5

Section

4.11.6

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Return bus message

count

Return bus

communication error

count

Return bus exception

error count

Return slave message

count

Return slave no

response count

Reads out the number of messages

detected on the line to the master.

Reads out the number of error

messages detected on the line to the

master.

Reads out the frequency of exception

errors to the master.

Reads out the number of the slave

message processing to the master.

(Including reception of broadcast

request messages)

Reads out the number of broadcast

request messages received to the

master.

Section

4.11.7

Section

4.11.8

Section

4.11.9

Section

4.11.10

Section

4.11.11

(Continued on next page)

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.1 MODBUS Standard Function Support List

UTILITY PACKAGE

(GX Configurator-MB)

4 - 2

MODBUS STANDARD FUNCTIONS

Table4.1 MODBUS standard function support list (continued)

Function

code

(Sub code)

Sub-function

code

16 Return slave NAK count

17 Return slave busy count

Function Description

Return bus character

overrun count

Return IOP overrun

error count

Clear overrun counter

and flag

Reads out the number of NAK

responses to the master.

The QJ71MB91 always returns "0".

Reads out the number of busy

responses to the master.

The QJ71MB91 always returns "0".

To the master, reads out the number of

times the request message size

exceeds the upper limit.

Reads the IOP overrun error counter

value to the master.

The QJ71MB91 returns to the master

the number of times the request

message size exceeds the upper limit.

(Same as the Return bus character

overrun count)

Clears the overrun error counter and

flag.

The QJ71MB91 clears the character

overrun error counter value.

Accessible

devices per

message

Broadcast Reference

Section

4.11.12

Section

4.11.13

Section

4.11.14

Section

4.11.15

Section

4.11.16

11 -

12 -

15 - Write multiple coils

Get communications

event counter

Get communications

event log

Acquires the number of messages

whose requested processing (read/

write, diagnostics, etc.) have been

normally completed.

Whether the action corresponding to the

request message is normally completed

or not can be checked.

Acquires the communications event log

of the QJ71MB91 into the master.

Writes values (ON/OFF) to multiple

coils.

1 to

1968 points

(Continued on next page)

Section

4.12

Section

4.13

Section

4.14

4 - 3

4.1 MODBUS Standard Function Support List

Remark

MODBUS STANDARD FUNCTIONS

Table 4.1 MODBUS standard function support list (continued)

Function

code

(Sub code)

16 - Write multiple registers

17 - Report slave ID

20(6) - Read file record

21(6) - Write file record

22 - Mask write register

23 -

Sub-function

code

Read/Write multiple

registers

- Read FIFO queue

Function Description

Writes values to multiple holding

registers.

Acquires the information of the slave

(QJ71MB91) mounted station into the

master.

Reads values of one or more extended

file registers.

Writes values to one or more extended

file registers.

Masks the values stored in a single

holding register with AND or OR and

writes the value.

Reads from or writes to multiple holding

registers.

Reads values from the holding

registers in FIFO queue structure.

Accessible

devices per

message

1 to

123 points

1 to

124 points

1 to

122 points

1 point

Read:

1 to

125 points

Write:

1 to

121 points

---

Broadcast Reference

Section

4.15

Section

4.16

Section

4.17

Section

4.18

Section

4.19

Section

4.20

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Read device

identification

* 1 The slave function of the QJ71MB91 does not support this function.

( This section (2))

Reads the module identification

information of the slave.

---

FUNCTION

The usable functions are limited when the QJ71MB91 is installed to a

MELSECNET/H remote I/O station.( This section (3))

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.1 MODBUS Standard Function Support List

UTILITY PACKAGE

(GX Configurator-MB)

4 - 4

MODBUS STANDARD FUNCTIONS

(2) Standard function support list for the master and slave functions

The following table indicates a standard function support list classified by the master and slave functions of the QJ71MB91.

Table4.2 Standard function support list for the master and slave functions

Function

code

(Sub code)

01 - Read coils

02 - Read discrete inputs

03 - Read holding registers

04 - Read input registers

05 - Write single coil

06 - Write single register

07 - Read exception status

Sub-function

code

00 Return query data

01 Restart communications option

02 Return diagnostic register

Function

Automatic

communication

function

Master function

MBRW

instruction

MBREQ

instruction

Slave

function

03 Change ASCII input delimiter

04 Force listen only mode

10 Clear counters and diagnostic register

11 Return bus message count

12 Return bus communication error count

13 Return bus exception error count

14 Return slave message count

15 Return slave no response count

16 Return slave NAK count

: Supported : Not supported

* 1 Since the MBREQ instruction allows users to create request message frames, function codes other

than the above can be also sent. ( Section 10.3)

(Continued on next page)

4 - 5

4.1 MODBUS Standard Function Support List

Remark

MODBUS STANDARD FUNCTIONS

Table4.2 Standard function support list for the master and slave functions (Continued)

Function

code

(Sub code)

11 - Get communications event counter

12 - Get communications event log

15 - Write multiple coils

16 - Write multiple registers

17 - Report slave ID

20(6) - Read file record

Sub-function

code

17 Return slave busy count

18 Return bus character overrun count

19 Return IOP overrun error count

20 Clear overrun counter and flag

Function

Automatic

communication

function

Master function

MBRW

instruction

MBREQ

instruction

Slave

function

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

21(6) - Write file record

22 - Mask write register

23 - Read/Write multiple registers

24 - Read FIFO queue

43 - Read device identification

* 1 Since the MBREQ instruction allows users to create request message frames, function codes other

than the above can be also sent. ( Section 10.3)

The usable functions are limited when the QJ71MB91 is installed to a

MELSECNET/H remote I/O station.( This section (3))

: Supported : Not supported

PRE-OPERATIONAL

MODBUS STANDARD

FUNCTIONS

FUNCTION

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.1 MODBUS Standard Function Support List

UTILITY PACKAGE

(GX Configurator-MB)

4 - 6

MODBUS STANDARD FUNCTIONS

(3) List of MODBUS standard functions supported when accessing a

MELSECNET/H remote I/O station

The following MODBUS standard functions are available when the QJ71MB91 mounted on a MELSECNET/H remote I/O station makes access to the MELSECNET/ H remote I/O station.

Table4.3 MODBUS standard function savailable for access to MELSECNET/H remote I/O station

Function

code

(Sub code)

01 - Read coils

02 - Read discrete inputs

03 - Read holding registers

04 - Read input registers

05 - Write single coil

06 - Write single register

07 - Read exception status

Sub-function

Code

* 1 The access target is the MELSECNET/H remote I/O station.

When the MELSECNET/H remote master station is the access target, available functions are the same as those shown in (2).

* 2 Accessing the MODBUS device that is not supported by the MELSECNET/H remote I/O station

results in error completion. (Exception code: 04 If the access target is the MELSECNET/H remote master station, it can be assigned to the control CPU device of the MELSECNET/H remote master station.

Function

Master function

Automatic

communication

function

MBRW

instruction

MBREQ

instruction

Slave function

: Supported : Supported with restrictions : Not supported

4 - 7

(Continued on next page)

4.1 MODBUS Standard Function Support List

MODBUS STANDARD FUNCTIONS

Table 4.3 MODBUS standard functions available for access to MELSECNET/H remote I/O station (continued)

Function

code

(Sub code)

Sub-function

code

00 Return query data

01 Restart communications option

02 Return diagnostic register

03 Change ASCII input delimiter

04 Force listen only mode

11 Return bus message count

Clear counters and diagnostic

Return bus communication

error count

Return bus exception error

count

Function

Automatic

communication

function

Master function

MBRW

instruction

MBREQ

instruction

Slave function

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

14 Return slave message count

16 Return slave NAK count

17 Return slave busy count

19 Return IOP overrun error count

20 Clear overrun counter and flag

Return slave no response

count

Return bus character overrun

count

* 1 The access target is the MELSECNET/H remote I/O station.

When the MELSECNET/H remote master station is the access target, available functions are the same as those shown in (2).

* 2 Accessing the MODBUS device that is not supported by the MELSECNET/H remote I/O station

results in error completion. (Exception code: 04 If the access target is the MELSECNET/H remote master station, it can be assigned to the control CPU device of the MELSECNET/H remote master station.

: Supported : Supported with restrictions : Not supported

(Continued on next page)

PRE-OPERATIONAL

MODBUS STANDARD

FUNCTIONS

FUNCTION

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.1 MODBUS Standard Function Support List

UTILITY PACKAGE

(GX Configurator-MB)

4 - 8

POINT

MODBUS STANDARD FUNCTIONS

Table 4.3 MODBUS standard functions available for access to MELSECNET/H remote I/O station (continued)

Function

code

(Sub code)

11 -

12 - Get communications event log

15 - Write multiple coils

16 - Write multiple registers

17 - Report slave ID

20(6) - Read file record

21(6) - Write file record

22 - Mask write register

23 - Read/Write multiple registers

24 - Read FIFO queue

Sub-function

code

Function

Get communications event

counter

Automatic

communication

function

Master function

MBRW

instruction

MBREQ

instruction

Slave function

43 - Read device identification

* 1 The access target is the MELSECNET/H remote I/O station.

When the MELSECNET/H remote master station is the access target, available functions are the same as those shown in (2).

* 2 Accessing the MODBUS device that is not supported by the MELSECNET/H remote I/O station

results in error completion. (Exception code: 04

If the access target is the MELSECNET/H remote master station, it can be assigned to the control CPU device of the MELSECNET/H remote master station.

When the QJ71MB91 is mounted to a MELSECNET/H remote I/O station, switch the access target using the Access target (when mounted to MELSECNET/H

remote I/O station) in the buffer memory (address: 000E

: Supported : Supported with restrictions : Not supported

)

H). ( Section 7.3.5)

4 - 9

4.1 MODBUS Standard Function Support List

Remark

DataAddress field Function code Error check

MODBUS Protocol Data Section

Section 4.3 to Section 4.20

MODBUS STANDARD FUNCTIONS

4.2 Frame Specifications

The following shows the frame specifications for the MODBUS protocol.

OVERVIEW

Figure 4.1 Frame specifications

Address field

Function code

Data

Error check

Table4.4 Frame specifications

Area name Description

[When master sends a request message to slave]

0: Sends a request message to all the slaves. (Broadcast)

1 to 247: Stores the target slave station No.

[When slave sends a response message to master]

The host station number is stored when sending a response message.

[When master sends a request message to slave]

The master specifies the number of the action to be taken by the slave.

[When slave sends a response message to master]

A requested function code is stored in the case of normal completion.

The most significant bit turns ON in the case of error completion.

[When master sends a request message to slave]

The information needed to execute the action specified by a function code is stored.

[When slave sends a response message to master]

The execution result of the action specified by a function code is stored.

An exception code is stored when failed.

The master adds a check code in a request message and transmits the request message.

The slave, which received the request message, recalculates the check code in the request

message and determines whether the message is correct or not.

The message is discarded if it has an error.

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

* 1 The error check method differs depending on the frame mode.( Section 4.2.1)

Refer to the following for the data size of each area.

Section 4.2.1

4.2 Frame Specifications

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4 - 10

Remark

Data

Start

Address field

Function code

Error check

END

(Start)

Address field

3.5 character time or more

1 byte 1 byte

0 to 252 bytes

2 bytes

3.5 character time or more

1 byte

Error check calculation range

MODBUS STANDARD FUNCTIONS

4.2.1 Frame mode

For the QJ71MB91, the following frame modes are available. The frame mode of the QJ71MB91 must be consistent with that of the target device.

(1) Available frame modes

(a) RTU mode

In this mode, frames are received or sent in binary codes. The frame specifications are compliant with the MODBUS protocol specifications.

Figure 4.2 Frame in RTU mode

The error check in the RTU mode is conducted by CRC (Cyclic Redundancy Check). The QJ71MB91 calculates the CRC by the following steps. Please follow the same steps to calculate the CRC when conducting an error check on the target device.

1) Load the register whose 16 bits are all "1".

2) The CRC is calculated every 8 bits from the upper bit of the frame. Calculate the 8 bits of the frame and the exclusive logical sum (XOR) of the bits in the above 1).

3) Shift the result of 2) by 1 bit to the right.

4) If the least significant bit of the above 2) is "1", calculate the exclusive OR

(XOR) from the result in 3) and the generator polynomial (A001

H).

If the least significant bit is "0", do not calculate the exclusive OR (XOR), but shift it by 1 bit to the right.

5) Repeat the above steps 3) and 4) until the bit is shifted up to 8 times.

6) Calculate the exclusive OR (XOR) from the result of 5) and the next 8 bits of

the frame.

7) Repeat steps 3) to 6).

4 - 11

4.2 Frame Specifications

4.2.1 Frame mode

8) Repeat the above operations until the end of the data unit is reached.

The final value is a calculated CRC value.

9) The CRC value is stored in the frame in the order from the lower 8 bits to the

upper 8 bits.

MODBUS STANDARD FUNCTIONS

The following is a calculation example in the case where function code 07H is sent to station No. 2.

CRC error check procedure 16-bit register (MSB) Flag

(Load the register whose 16 bits are all "1")

H(Station No.)

Exclusive OR (XOR)

Table4.5 CRC calculation procedures

1111

0000

1111

0010

1101

OVERVIEW

Shift 1

Generator polynomial

Exclusive OR (XOR)

Shift2

Generator polynomial

Exclusive OR (XOR)

Shift3

Shift4

Generator polynomial

Exclusive OR (XOR)

Shift5

Shift6

Generator polynomial

Exclusive OR (XOR)

Shift7

Shift8

Generator polynomial

Exclusive OR (XOR)

07H(Function)

Exclusive OR (XOR) 1000 0001

Shift 1

Generator polynomial

Exclusive OR (XOR)

Shift2

Generator polynomial

Exclusive OR (XOR)

0111

1010

1101

0110

1010

1100

0110

0011

1010

1001

0100

0010

1010

1000

0100

0010

1010

1000

0100

1010

1110

0111

1010

1101

1111

0000

1111

0000

1111

0111

0011

0000

0011

1001

0100

0000

0100

0010

0001

0000

0001

0000

1111

0000

1111

0000

1111

0000

1111

0000

1111

0111

0011

0000

0011

0000

0011

1001

0000

1001

0100

0000

0100

1110

0001

1111

0001

1110

1111

0001

1110

1111

0001

1110

1111

0001

1110

0111

1001

1100

0001

1101

1110

0001

1111

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Shift3

Generator polynomial

Exclusive OR (XOR)

Shift4

Shift5

Generator polynomial

Exclusive OR (XOR)

Shift6

Shift7

Shift8

CRC value 12H 41H

0110

1010

1100

0110

0011

1010

1001

0100

0010

0001

1000

0000

1000

0100

0010

0000

0010

1001

0100

0010

0000

0010

0001

0000

1000

0100

4.2 Frame Specifications

4.2.1 Frame mode

0111

0001

0110

0011

1001

0001

1000

0100

0010

0001

4 - 12

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

Remark

MODBUS STANDARD FUNCTIONS

Address field

H) (07H)

(02

Figure 4.3 Frame for CRC calculation

Function code CRC (Error check)

(41H) (12H)

(b) ASCII mode

In this mode, frames are received or sent in units of 2 characters (2 bytes) in ASCII codes. The frame specifications are compliant with the MODBUS protocol specifications.

Start END

(3A

Address field

2 characters

Function code

2 characters

Error check calculation range

Figure 4.4 Frame in ASCII mode

Data

n x 2 characters (n = 0 to 252)

Error check

2 characters

CR + LF

(0DH) (0AH)

The error check in the ASCII mode is conducted by LRC (Longitudinal Redundancy Check). The QJ71MB91 calculates the LRC by the following steps. Please follow the same steps to calculate the LRC when conducting an error check on the target device.

1) To calculate the LRC, convert the ASCII codes within the error check range

into the RTU format (binary).

2) Add the figures in units of contiguous 8 bits in the frame. (Excluding carries

during addition.)

3) Change the result of the above 2) to a 2's complement. (Reverse the bits and

add 01

H.)

4) Convert the result of 3) to an ASCII code.

4 - 13

4.2 Frame Specifications

4.2.1 Frame mode

Head input number Read points

Start

Address field

(02

Function code

(01

LRC

(Error check)

(F5

H 30H 32H 30H 31H

(00H) (00H) (00H) (08H)

H 30H 30H 30H 30H 30H 30H 38H 46H 35H 0DH

"CR" "LF"

MODBUS STANDARD FUNCTIONS

The following are calculation examples in the case where function code 01H is sent to station No. 2.

Table4.6 LRC calculation procedure (when sending a request message)

LRC in request message transmission

Station No. (address field)

Function code

Head coil number (H)

Head coil number(L)

Read points (H)

Read points (L)

0000

+0000

0010

0001

0000

1000

OVERVIEW

Addition result

Bit reversal 1

2's complement

LRC (Error check) F5 F 5

Table4.7 LRC calculation procedure (when receiving a response message)

LRC in reception of a response message

Station No. (address field)

Function code

Head coil number(H)

Head coil number(L)

Read points (H)

Read points (L)

LRC (Error check)

Addition result 00 0000 0000

0000

+1111

0000

1111

0010

0001

0000

1000

0101

1011

0100

0101

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Figure 4.5 Frame for LRC calculation

(2) Frame mode setting

The frame mode is set in the intelligent function module switch setting.

( Section 6.6)

4.2 Frame Specifications

4.2.1 Frame mode

4 - 14

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

MODBUS STANDARD FUNCTIONS

4.3 Protocol Data Unit Formats by Functions

This section describes MODBUS protocol data unit formats used in the QJ71MB91.

(1) Precautions

(a) Device number specified in messages

When specifying a device number in a message, specify it as "(Device number) 1". However, this does not apply to the file and device numbers specified for reading/ writing the extended file register.

(Example) When reading input 32 (100032) with Read Discrete Inputs (FC: 02)

Function code

Specify 31 (001FH) for the head input number to read the input 32 (100032) status.

Figure 4.6 Specifying the MODBUS device number

Head input number

001FH

(H)

Data

Read points

0001

(L) (L)

(H)

The device number to be stored in the response message is "(Device number of actually read/written device) - 1".

(b) When the QJ71MB91 receives a broadcast request message

Although the processing (read/write, diagnostics, etc.) requested by the request message is performed, no response message is sent to the master.

The request message is discarded except for a particular case. To receive the request message, change it to the online mode.

( Section 4.11.5)

4 - 15

4.3 Protocol Data Unit Formats by Functions

MODBUS STANDARD FUNCTIONS

(2) When the processing is completed in error at the slave (QJ71MB91)

When the processing (read/write, diagnostics, etc.) requested by the request

message is completed in error, an exception code is sent to the master.( "Response message formats (when completed with an error)" in Section 4.4 to 4.20.)

(a) Storage location of exception code and error code

The exception code is also stored in the buffer memory of the QJ71MB91. Furthermore, for identification of detailed causes, an error code is stored in the QJ71MB91 buffer memory. The exception code and error codes can be confirmed by the error log area of the

buffer memory (address: 0CFE

(3) How to see the request/response message formats provided in Section

4.4 to 4.20

(a) Request/Response message format diagram

The following shows how to see the request/response message format diagrams provided in Section 4.4 to 4.20.

Area name

Function code

H to 0DFFH).( Section 11.4)

Data

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

Frame contents

[For request message format] Setting range

[For response message format] Value stored to the response message

Figure 4.7 Request/Response message format diagram

Function

code

(01

1 byte (8 bits) 1 byte (8 bits)

Head coil number

(0000

(H)

H to FFFFH)

(L) (L)

When a single data is expressed

. . .

by 2 bytes, set the upper byte (8 bits) as (H) and the lower byte (8 bits) as (L).

Read points

H to 07D0H)

(0001

(H)

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

4.3 Protocol Data Unit Formats by Functions

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4 - 16

Data

(L)

Data

(L)

(L)(L)

Data

(L)

Read points

(30

(30H)

(33H)

(46H)

(RTU mode)

Function code

Function

code (01

Head coil number

(006E

Read points

(003FH)

Convert RTU mode to ASCII mode

(ASCII mode)

Function code

(30

(31H)

Head coil number

(30

(30H)

(36H)

(45

(H)

(H) (H)

MODBUS STANDARD FUNCTIONS

(b) Frame mode of the message format

The message formats in Section 4.4 to 4.20 are based on the case in the RTU mode. For use in ASCII mode, convert the values into ASCII codes.

(Conversion example)

Figure 4.8 Conversion example from RTU mode to ASCII mode

The response message formats issued from the slave to the master differs depending on whether the slave has normally completed or failed to handle the requested processing (read/write, diagnostics, etc.) The formats for normal and error completions are shown in Section 4.4 to 4.20.

4 - 17

4.3 Protocol Data Unit Formats by Functions

Data

(L) (L)

Function code

Function

code

(01

Head coil number

(0000

H to FFFFH)

Read points

(0001H to 07D0H)

(H)

Data

b0b1b2b3b4b5b6b7

Function code

Function

code (01

Number of read bytes

Device data

(Number of read bytes n)

(Device data 1 to n)

Device data 1

Device data n

Bit device storage order

0 : OFF 1 : ON

The read coil statuses are stored in order from low-order to high-order bits. When the number of read points is not a multiple of 8, the excess bits turn to 0.

Data

Function code

(81

Function code

Exception code*

MODBUS STANDARD FUNCTIONS

4.4 Read Coils (FC: 01)

Reads the status (ON/OFF) of one or more coils.

(1) Request message format (Master Slave)

OVERVIEW

SYSTEM

CONFIGURATION

Figure 4.9 Read coils (Request message)

(2) Response message format (Slave Master)

(When completed normally)

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

(When completed with an error)

Figure 4.11 Read coils (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Figure 4.10 Read coils (Normal response message)

Section 11.4

4.4 Read Coils (FC: 01)

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4 - 18

Data

(L) (L)

Function code

Function

code

(02

Head input number

(0000

H to FFFFH)

Read points

(0001H to 07D0H)

(H)

Data

b0b1b2b3b4b5b6b7

Function code

Function

code (02

Number of read bytes

Device data

(Number of read bytes n)

(Device data 1 to n)

Device data 1

Device data n

Bit device storage order

0 : OFF 1 : ON

The read input statuses are stored in order from low-order to high-order bits. When the number of read points is not a multiple of 8, the excess bits turn to 0.

Data

Function code

Function

code (82

Exception code*

MODBUS STANDARD FUNCTIONS

4.5 Read Discrete Inputs (FC: 02)

Reads the status (ON/OFF) of one or more inputs.

(1) Request message format (Master Slave)

Figure 4.12 Read discrete inputs (Request message)

(2) Response message format (Slave Master)

(When completed normally)

4 - 19

(When completed with an error)

Figure 4.14 Read discrete inputs (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

4.5 Read Discrete Inputs (FC: 02)

Figure 4.13 Read discrete inputs (Normal response message)

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

Data

(L) (L)

Function code

Function

code (03

Head holding register number

(0000

H to FFFFH)

Read points

(0001H to 007DH)

(H)

Data

. . .

(L) (L)

Function code

Function

code (03

Number of read bytes

n x 2 *1

Device data

(Number of read bytes n x 2)

*1 For example, if n = 4, the number of read bytes is calculated as 4 x 2 = 8 bytes.

(H) (H)

Data

Function code

Function

code

(83

Exception code *

MODBUS STANDARD FUNCTIONS

4.6 Read Holding Registers (FC: 03)

Reads the values of one or more holding registers.

(1) Request message format (Master Slave)

OVERVIEW

SYSTEM

CONFIGURATION

Figure 4.15 Read holding registers (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.16 Read holding registers (Normal response message)

(When completed with an error)

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Figure 4.17 Read holding registers (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4.6 Read Holding Registers (FC: 03)

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4 - 20

Data

(L) (L)

Function code

Function

code

(04

Head input register number

(0000

H to FFFFH)

Read points

(0001H to 007DH)

(H) (H)

Data

Function code

Function

code

(84

Exception code *

MODBUS STANDARD FUNCTIONS

4.7 Read Input Registers (FC: 04)

Reads the values of one or more input registers.

(1) Request message format (Master Slave)

Figure 4.18 Read input registers (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Function code

Function

code

)

(04

Number of read bytes

n x 2 *

Figure 4.19 Read input registers (Normal response message)

Device data

(H)

Data

. . .

(L) (L)

(Number of read bytes n x 2)

*1 For example, if n = 4, the number of read bytes is calculated as 4 x 2 = 8 bytes.

Device data

(H)

(When completed with an error)

Figure 4.20 Read input registers (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 21

4.7 Read Input Registers (FC: 04)

Data

(L) (L)

Function code

Function

code

(05

Coil number

(0000

H to FFFFH)

ON/OFF specification

0000

H : OFF

FF00

H : ON

(H)

Data

Function code

Function

code (85

Exception code*

MODBUS STANDARD FUNCTIONS

4.8 Write Single Coil (FC: 05)

Writes a value (ON/OFF) to one coil.

(1) Request message format (Master Slave)

OVERVIEW

SYSTEM

CONFIGURATION

Figure 4.21 Write single coil (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

Figure 4.22 Write single coil (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

4.8 Write Single Coil (FC: 05)

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4 - 22

Data

(L) (L)

Function code

Function

code (06

Holding register number

(0000

H to FFFFH)

Write data

(0000H to FFFFH)

(H)

Data

Function code

Function

code

(86

Exception code*

MODBUS STANDARD FUNCTIONS

4.9 Write Single Register (FC: 06)

Writes a value to one holding register.

(1) Request message format (Master Slave)

Figure 4.23 Write single register (Request Message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

Figure 4.24 Write single register (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 23

4.9 Write Single Register (FC: 06)

Function code

(07

Data

Function code

Function

code (07

Error information *1

Data

Function code

Function

code

(87

Exception code *

MODBUS STANDARD FUNCTIONS

4.10 Read Exception Status (FC: 07)

Reads error status.

(1) Request message format (Master Slave)

OVERVIEW

SYSTEM

CONFIGURATION

Figure 4.25 Read exception status (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.26 Read exception status (Normal request message)

* 1 The data of the device specified in the Setting error status read device (address: 000AH to 000BH)

in the buffer memory are stored in the error information area. ( Section 7.3.4)

(When completed with an error)

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

FUNCTION

Figure 4.27 Read exception status (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4.10 Read Exception Status (FC: 07)

4 - 24

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

Function code

Function

code

(08

Sub-function code

(0000

Arbitrary data

(H)

Data

Function code

Function

code

(88

Exception code*

MODBUS STANDARD FUNCTIONS

4.11 Diagnostics (FC: 08)

Executes the various diagnostics and checks the QJ71MB91 status and communication status.

4.11.1 Return query data (sub-function code: 00)

Returns the contents of the request message without change. Used to check if the network or the target device is operating normally. (Loopback test)

(1) Request message format (Master Slave)

Figure 4.28 Return query data (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

Figure 4.29 Return query data (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 25

4.11 Diagnostics (FC: 08)

4.11.1 Return query data (sub-function code: 00)

MODBUS STANDARD FUNCTIONS

4.11.2 Restart communications option (sub-function code: 01)

Initializes the communication port of the receiving channel side and restarts the slave function. Restart is performed after returning the response message corresponding to a request message. The operation status returns to online mode when it was in the listen only mode.

The following data are cleared when executing the restart communications option.

• Data being received

• CH1/2 side error response code storage area in the buffer memory (address:

/0004H)

0002

• CH1/2 side detailed LED status storage area in the buffer memory (address:

/0007H)

0006

• Diagnostic counter ( Section 11.3)

• The ERR. LED OFF

• Communications event count ( Section 4.12)

• Communications event log ( Section 4.13)

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

* 1 Clears only the receiving channel side area. * 2 Clears the errors of the channel that has received the request message.

As the errors of other channels are not cleared, the LED will not turn off if an error has occurred on any other channel.

* 3 Clears the data when the communications event log clear is specified in the request message.

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

4.11 Diagnostics (FC: 08)

4.11.2 Restart communications option (sub-function code: 01)

4 - 26

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function

code

(08

Function code

Sub-function code

(0001

Clear setting of

Communications event log

0000

H: Not clear

FF00

H: Clear

(H)

Data

Function code

Function

code

(88

Exception code*

MODBUS STANDARD FUNCTIONS

(1) Request message format (Master Slave)

Figure 4.30 Restart communications option (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change. However, if a request message is received during listen only mode, the status will only return to online mode and no response message will be returned.

(When completed with an error)

Figure 4.31 Restart communications option (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 27

4.11 Diagnostics (FC: 08)

4.11.2 Restart communications option (sub-function code: 01)

Remark

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0002

(0000

(H) (H)

MODBUS STANDARD FUNCTIONS

4.11.3 Return diagnostic register (sub-function code: 02)

Reads out the detailed LED status of the QJ71MB91 to the master.

(1) Request message format (Master Slave)

Figure 4.32 Return diagnostic register (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Function code

Function

code

(08

Sub-function code

(H)

(0002

(L)

Diagnostic register value

(H)

Data

(L)

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

0 0 0 1/0 1/0 1/0 1/0 1/0 0 0 0 1/0 1/0 1/0 1/0 1/0

The QJ71MB91 stores the lower 8 bits of the buffer memory's Detailed LED status as a diagnostic register. (address: 0006

Figure 4.33 Return diagnostic register (Normal response message)

b0b1b2b3b4b5b6b7b8b9b10b11b12b13b14b15

CH1 C/N

CH1 P/S

CH1 PRO.

CH1 SIO

CH1 ERR.

Unused (Fixed to 0)

CH2 C/N

CH2 P/S

CH2 PRO.

CH2 SIO

CH2 ERR.

Unused (Fixed to 0)

CH1 side Detailed LED status (0: OFF, 1: ON)

CH2 side Detailed LED status (0: OFF, 1: ON)

H/0007H)

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

Refer to the following for each items of the detailed LED status.

Section 11.2

4.11.3 Return diagnostic register (sub-function code: 02)

4.11 Diagnostics (FC: 08)

4 - 28

UTILITY PACKAGE

(GX Configurator-MB)

Data

Function code

Function

code (88

Exception code*

MODBUS STANDARD FUNCTIONS

(When completed with an error)

Figure 4.34 Return diagnostic register (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 29

4.11 Diagnostics (FC: 08)

4.11.3 Return diagnostic register (sub-function code: 02)

POINT

Start

END

Address field

2 characters

Function code

2 characters

Data

n x 2 characters

(n = 0 to 252)

Error check

2 characters

CR + LF

(0D

H) (0AH)

Change this into a specified data.

(3A

(L)

Data

Function code

Function

code

(08

Sub-function code

(0003

Input delimiter

setting

(00

H to FFH)

(00

(H)

Data

Function code

Function

code

(88

Exception code*

MODBUS STANDARD FUNCTIONS

4.11.4 Change ASCII input delimiter (sub-function code: 03)

Changes the 2nd byte (LF(0AH)) of the end code in the ASCII mode to a specified data. The specified data is stored in the 2nd byte of end code in the buffer memory. (address:

/0F4CH)

0F0C

Figure 4.35 Change part in the end code

(1) Request message format (Master Slave)

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

Figure 4.36 Change ASCII input delimiter (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

Figure 4.37 Change ASCII input delimiter (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

This function is used only for 1:1 connections. Do not use this function for 1:n connections.

PARAMETER SETTING

4.11.4 Change ASCII input delimiter (sub-function code: 03)

4.11 Diagnostics (FC: 08)

4 - 30

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(0004

(0000

(H)

Data

Function code

Function

code

(88

Exception code*

MODBUS STANDARD FUNCTIONS

4.11.5 Force listen only mode (sub-function code: 04)

Places a slave into the offline mode. Used when disconnecting a slave from the network.

When QJ71MB91 is set in the listen only mode, the status is as follows:

• Ignores all request messages except for those of restart communications

option.( Section 4.11.2)

• Stops counting of the diagnostic counter.( Section 11.3)

• Continues recording with the communications event log.( Section 4.13)

(1) Request message format (Master Slave)

Figure 4.38 Force listen only mode (Request message)

(2) Response message format (Slave Master)

(When completed normally) No response message is returned because the listen only mode (offline status) is active.

(When completed with an error)

Figure 4.39 Force listen only mode (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 31

4.11 Diagnostics (FC: 08)

4.11.5 Force listen only mode (sub-function code: 04)

POINT

MODBUS STANDARD FUNCTIONS

1. Whether the QJ71MB91 has been switched to listen only mode or not can be checked in the Communications mode of the buffer memory (address: 0F0D

H).

0F4D

H: Online mode

0000

H: Listen only mode

0001

2. The listen only mode can be changed to online mode by either of the following:

• Restart communications option ( Section 4.11.2)

• Power OFF ON, programmable controller CPU reset

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

4.11 Diagnostics (FC: 08)

4.11.5 Force listen only mode (sub-function code: 04)

4 - 32

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

MODBUS STANDARD FUNCTIONS

4.11.6 Clear counters and diagnostic register (sub-function code: 10)

Clears counters (e.g. message count). Also, clears the diagnostic register and the error of the channel where the request message has been received.

The following counters will be cleared.( Section 11.3)

• Bus message count

• Bus communication error count

• Exception error count

• Slave message count

• Slave no-response count

• Slave NAK count

• Slave busy count

• Character overrun error count

• Communications event count ( Section 4.12)

The following diagnostic resisters will be cleared.

• CH1/2 side detailed LED status storage area of the buffer memory (address:

/0007H)

0006

• CH1/2 side error response code storage area of the buffer memory (address:

/0004H)

0002

* 1 Clears only the receiving channel side area.

4 - 33

4.11 Diagnostics (FC: 08)

4.11.6 Clear counters and diagnostic register (sub-function code: 10)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000A

(0000

(H) (H)

Data

Function code

Function

code

(88

Exception code*

MODBUS STANDARD FUNCTIONS

(1) Request message format (Master Slave)

Figure 4.40 Clear counters and diagnostic register (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

Figure 4.41 Clear counters and diagnostic register (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

MODBUS STANDARD

PRE-OPERATIONAL

PROCEDURES AND

FUNCTIONS

FUNCTION

SETTINGS

4.11.6 Clear counters and diagnostic register (sub-function code: 10)

4.11 Diagnostics (FC: 08)

4 - 34

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Function code

Function

code

(08

Data

(L)

Sub-function code

(000B

(0000

(H) (H)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(000B

Bus message count value

(0000

H to FFFFH) *

The QJ71MB91 returns the bus message count value of the buffer memory to the master. (address: 0F00

H/0F40H)

(H)

Data

Function code

Function

code

(88

Exception

code *

MODBUS STANDARD FUNCTIONS

4.11.7 Return bus message count (sub-function code: 11)

Reads out the number of messages detected on the line to the master.

(1) Request message format (Master Slave)

Figure 4.42 Return bus message count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.43 Return bus message count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.44 Return bus message count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 35

4.11 Diagnostics (FC: 08)

4.11.7 Return bus message count (sub-function code: 11)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000C

(0000

(H)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000C

Bus communication

error count value

(0000

H to FFFFH) *

The QJ71MB91 returns the bus communication error count value of the buffer memory to the master. (address: 0F01

H/0F41H)

(H)

Data

Function code

Function

code

(88

Exception code *

MODBUS STANDARD FUNCTIONS

4.11.8 Return bus communication error count (sub-function code: 12)

Reads out the number of error messages detected on the line to the master.

(1) Request message format (Master Slave)

Figure 4.45 Return bus communication error count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

OVERVIEW

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 4.46 Return bus communication error count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.47 Return bus communication error count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.11.8 Return bus communication error count (sub-function code: 12)

4.11 Diagnostics (FC: 08)

4 - 36

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(000D

(0000

(H)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000D

Exception error count value

(0000

H to FFFFH) *

The QJ71MB91 returns the exception error count value of the buffer memory to the master. (address: 0F0A

H/0F4AH)

(H)

Data

Function code

Function

code

(88

Exception code *

MODBUS STANDARD FUNCTIONS

4.11.9 Return bus exception error count (sub-function code: 13)

Reads out the frequency of exception errors to the master.

(1) Request message format (Master Slave)

Figure 4.48 Return bus exception error count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.49 Return bus exception error count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.50 Return bus exception error count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 37

4.11 Diagnostics (FC: 08)

4.11.9 Return bus exception error count (sub-function code: 13)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000E

(0000

(H)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(000E

Slave message count value

(0000

H to FFFFH) *

The QJ71MB91 returns the slave message count value of the buffer memory to the master. (address: 0F06

H/0F46H)

(H)

Data

Function code

Function

code

(88

Exception code *

MODBUS STANDARD FUNCTIONS

4.11.10 Return slave message count (sub-function code: 14)

Reads out the number of the slave message processing to the master. (Including receive of request messages from broadcast.)

OVERVIEW

(1) Request message format (Master Slave)

Figure 4.51 Return slave message count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 4.52 Return slave message count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.53 Return slave message count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.11 Diagnostics (FC: 08)

4.11.10 Return slave message count (sub-function code: 14)

4 - 38

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(000F

(0000

(H)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(000F

Slave no-response count value

(0000

H to FFFFH) *

The QJ71MB91 returns the slave no response count value of the buffer memory to the master. (address: 0F07

H/0F47H)

(H)

Data

Function code

Function

code (88

Exception code *

MODBUS STANDARD FUNCTIONS

4.11.11 Return slave no response count (sub-function code: 15)

Reads to out the number of broadcast request messages received to the master.

(1) Request message format (Master Slave)

Figure 4.54 Return slave no response count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.55 Return slave no response count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.56 Return slave no response count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 39

4.11 Diagnostics (FC: 08)

4.11.11 Return slave no response count (sub-function code: 15)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0010

Sub-function code

(0000

(H)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0010

Slave NAK count value

(0000

H) *

The QJ71MB91 returns the slave NAK count value of the buffer memory to the master. (address: 0F08

H/0F48H)

(H) (H)

Data

Function code

Function

code

(88

Exception

code *2

MODBUS STANDARD FUNCTIONS

4.11.12 Return slave NAK count (sub-function code: 16)

Reads out the number of NAK responses to the master. The QJ71MB91 always returns "0".

OVERVIEW

(1) Request message format (Master Slave)

Figure 4.57 Return slave NAK count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 4.58 Return slave NAK count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.59 Return slave NAK count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.11 Diagnostics (FC: 08)

4.11.12 Return slave NAK count (sub-function code: 16)

4 - 40

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0011

(0000

(H)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0011

Slave busy count value

(0000

H) *

The QJ71MB91 returns the slave busy count value of the buffer memory to the master. (address: 0F09

H/0F49H)

(H)

Data

Function code

Function

code

(88

Exception

code *

MODBUS STANDARD FUNCTIONS

4.11.13 Return slave busy count (sub-function code: 17)

Reads out the number of busy responses to the master. The QJ71MB91 always returns "0".

(1) Request message format (Master Slave)

Figure 4.60 Return slave busy count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.61 Return slave busy count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.62 Return slave busy count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 41

4.11 Diagnostics (FC: 08)

4.11.13 Return slave busy count (sub-function code: 17)

Remark

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(0012

(0000

(H)

(L)

Data

(L)

Function code

Function

code (08

)

Sub-function code

(0012

)

Bus character overrun

count value

(0000

to FFFFH) *

The QJ71MB91 returns the bus character overrun count value of the buffer memory to the master. (address: 0F02

/0F42H)

(H)

Data

Function code

Function

code

(88

Exception code *

MODBUS STANDARD FUNCTIONS

4.11.14 Return bus character overrun count (sub-function code: 18)

To the master, reads out the number of times the request message size exceeds the upper limit.

OVERVIEW

(1) Request message format (Master Slave)

Figure 4.63 Return bus character overrun count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 4.64 Return bus character overrun count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.65 Return bus character overrun count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

Refer to the following for the size of request messages.

Section 4.2.1

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

4.11.14 Return bus character overrun count (sub-function code: 18)

4.11 Diagnostics (FC: 08)

4 - 42

UTILITY PACKAGE

(GX Configurator-MB)

(L)

Data

(L)

Function code

Function

code

(08

Sub-function code

(0013

(0000

(H)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(0013

Bus character

overrun count value

(0000

H to FFFFH) *

The QJ71MB91 returns the bus character overrun count value of the buffer memory to the master. (address: 0F02

H/0F42H)

(H)

Data

Function code

Function

code

(88

Exception

code *

MODBUS STANDARD FUNCTIONS

4.11.15 Return IOP overrun error count (sub-function code: 19)

Reads the IOP overrun error counter value to the master. The QJ71MB91 returns to the master the number of times the request message size exceeds the upper limit. (Same as the Return bus character overrun count)

(1) Request message format (Master Slave)

Figure 4.66 Return IOP overrun error count (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.67 Return IOP overrun error count (Normal response message)

* 1 Refer to the following for the relevant counts, count clear methods and precautions.

Section 11.3

(When completed with an error)

Figure 4.68 Return IP overrun error count (Exception message)

* 2 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

4 - 43

4.11 Diagnostics (FC: 08)

4.11.15 Return IOP overrun error count (sub-function code: 19)

(L)

Data

(L)

Function code

Function

code (08

Sub-function code

(0014

(0000

(H)

Data

Function code

Function

code

(88

Exception

code*

MODBUS STANDARD FUNCTIONS

4.11.16 Clear overrun counter and flag (sub-function code: 20)

Clears the overrun error counter and flag. The QJ71MB91 clears the character overrun error counter value.

OVERVIEW

(1) Request message format (Master Slave)

Figure 4.69 Clear overrun counter and flag (Request message)

(2) Response message format (Slave Master)

(When completed normally) The slave returns the request message received from the master without change.

(When completed with an error)

SYSTEM

CONFIGURATION

SPECIFICATIONS

MODBUS STANDARD

FUNCTIONS

Figure 4.70 Clear overrun counter and flag (Exception message)

* 1 Exception and error codes are stored in the buffer memory in the case of error completion.

Refer to the following for storage location, confirmation methods, and detailed contents.

Section 11.4

FUNCTION

PRE-OPERATIONAL

PROCEDURES AND

SETTINGS

PARAMETER SETTING

UTILITY PACKAGE

(GX Configurator-MB)

4.11.16 Clear overrun counter and flag (sub-function code: 20)

4.11 Diagnostics (FC: 08)

4 - 44

POINT

Function code

Function

code (0B

(L)

Data

(L)

Function code

Function

code (0B

Program command status

(0000

H) *

Communications

event count value

(0000

H to FFFFH) *

The QJ71MB91 stores the communications event count value of the buffer memory as the communications event count value. (address: 0F0B

H/0F4BH)

(H)

MODBUS STANDARD FUNCTIONS

4.12 Get Communications Event Counter (FC: 11)

Acquires the number of messages whose requested actions (read/write, diagnostics, etc.) have been normally completed. Whether the action corresponding to the request message is normally completed or not can be checked.

(1) Request message format (Master Slave)

Figure 4.71 Get communications event counter (Request message)

(2) Response message format (Slave Master)

(When completed normally)

Figure 4.72 Get communications event counter (Normal response message)

* 1 Since the QJ71MB91 does not support any program commands, 0000H is stored. * 2 The count is stopped if it has reached FFFF

Reset the counter by either of the following methods when restarting the count.

Clearing the counter and diagnostic register ( Section 4.11.6)

Restart communications option ( Section 4.11.2)

Power OFF ON, or programmable controller CPU reset

The communications event counter counts only when the processing (read/write, diagnostics, etc.) has completed normally. The communications event counter does not count in the case of the following:

• The processing has completed with an error.

• When receiving a request message containing a function code that the QJ71MB91 does not support

• When receiving the Get communications event counter (FC: 11) and Get communications event log (FC: 12)

4 - 45

4.12 Get Communications Event Counter (FC: 11)

Mitsubishi Electric QJ71MB91, SW1D5C-QMBU-E User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SAFETY PRECAUTIONS

CONDITIONS OF USE FOR THE PRODUCT

REVISIONS

INTRODUCTION

CONTENTS

COMPLIANCE WITH EMC AND LOW VOLTAGE DIRECTIVES

THE MANUAL'S USAGE AND STRUCTURE

ABOUT THE GENERIC TERMS AND ABBREVIATIONS

MEANINGS AND DEFINITIONS OF TERM

PRODUCT CONFIGURATION

CHAPTER1 OVERVIEW

1.1 Features

CHAPTER2 SYSTEM CONFIGURATION

2.1 Applicable Systems

2.2 Network Configuration

2.3 Precautions for System Configuration

2.4 How to Check the Function Version/Software Version

CHAPTER3 SPECIFICATIONS

3.1 Performance Specifications

3.2 RS-232 Interface Specification

3.2.1 RS-232 connector specification

3.2.2 RS-232 cable specification

3.3 RS-422/485 Interface Specification

3.3.1 RS-422/485 terminal block specification

3.3.2 RS-422/485 cable specification

3.3.3 Precautions when transferring data using RS-422/485 line

3.4 I/O Signals for Programmable Controller CPU

3.4.1 I/O signal list

3.5 Applications and Assignment of Buffer Memory

3.5.1 Buffer memory list

CHAPTER4 MODBUS STANDARD FUNCTIONS

4.1 MODBUS Standard Function Support List

4.2 Frame Specifications

4.2.1 Frame mode

4.3 Protocol Data Unit Formats by Functions

4.4 Read Coils (FC: 01)

4.5 Read Discrete Inputs (FC: 02)

4.6 Read Holding Registers (FC: 03)

4.7 Read Input Registers (FC: 04)

4.8 Write Single Coil (FC: 05)

4.9 Write Single Register (FC: 06)

4.10 Read Exception Status (FC: 07)

4.11 Diagnostics (FC: 08)

4.11.1 Return query data (sub-function code: 00)

4.11.2 Restart communications option (sub-function code: 01)

4.11.3 Return diagnostic register (sub-function code: 02)

4.11.4 Change ASCII input delimiter (sub-function code: 03)

4.11.5 Force listen only mode (sub-function code: 04)

4.11.6 Clear counters and diagnostic register (sub-function code: 10)

4.11.7 Return bus message count (sub-function code: 11)

4.11.8 Return bus communication error count (sub-function code: 12)

4.11.9 Return bus exception error count (sub-function code: 13)

4.11.10 Return slave message count (sub-function code: 14)

4.11.11 Return slave no response count (sub-function code: 15)

4.11.12 Return slave NAK count (sub-function code: 16)

4.11.13 Return slave busy count (sub-function code: 17)

4.11.14 Return bus character overrun count (sub-function code: 18)

4.11.15 Return IOP overrun error count (sub-function code: 19)

4.11.16 Clear overrun counter and flag (sub-function code: 20)

4.12 Get Communications Event Counter (FC: 11)