Mitsubishi Electric MELSEC Q Series User manual

MELSEC-Q/L Ethernet Interface Module
User's Manual (Web function)
-QJ71E71-100
-QJ71E71-B5
-QJ71E71-B2
-LJ71E71-100

1
SAFETY PRECAUTIONS
(Read these precautions before using this product.)
Before using this product, please read this manual and the relevant manuals carefully and pay full attention
to safety to handle the product correctly.
The precautions given in this manual are concerned with this product only. For the safety precautions of the
programmable controller system, refer to the user's manual for 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 the
network.
Failure to do so may result in an accident due to an incorrect output or malfunction.
●To prevent the malfunction of the programmable controller system due to harmful e-mails, take
preventive measures (such as antivirus measures) so that the mail server for this module does not
receive harmful e-mails.
●When connecting a peripheral with the CPU module or connecting a personal computer with an
intelligent function module to modify data of a running programmable controller, configure an interlock
circuit in the sequence program to ensure that the entire system will always operate safely.
For program modification and operating status change, read relevant manuals carefully and ensure
the safety before operation.
Especially, 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.
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.

2
[Design Precautions]
[Design Precautions]
[Security Precautions]
[Operating Precautions]
WARNING
●Do not write any data in 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 CPU module to the
intelligent function module.
Doing so may cause malfunction of the programmable controller system.
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.
●When changing the operating status of the CPU module (such as remote RUN/STOP) from the
external device, select "Always wait for OPEN (Communication possible at STOP time)" for the "Initial
timing" setting in the network parameter.
The communication line will be closed when "Do not wait for OPEN (Communications impossible at
STOP time)" is selected and the remote STOP is executed from the external device.
Consequently, the CPU module cannot reopen the communication line, and the external device
cannot execute the remote RUN.
WARNING
●To maintain the security (confidentiality, integrity, and availability) of the programmable controller and
the system against unauthorized access, denial-of-service (DoS) attacks, computer viruses, and other
cyberattacks from external devices via the network, take appropriate measures such as firewalls,
virtual private networks (VPNs), and antivirus solutions.
CAUTION
●When changing data and operating status, and modifying program of the running programmable
controller from a personal computer connected to an intelligent function module, read relevant
manuals carefully and ensure the safety before operation.
Incorrect change or modification may cause system malfunction, damage to the machines, or
accidents.

3
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.
(3) Mitsubishi shall have no responsibility or liability for any problems involving programmable controller trouble and system
trouble caused by DoS attacks, unauthorized access, computer viruses, and other cyberattacks.

4
INTRODUCTION
Thank you for purchasing the Mitsubishi MELSEC-Q or -L series programmable controllers.
This manual describes how to use the Web functions with the Ethernet interface module.
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 or -L 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.
Please make sure that the end users read this manual.
Remark
Unless otherwise specified, this manual describes the program examples in which the I/O numbers of X/Y00 to X/Y1F are
assigned for the Ethernet interface module.
For I/O number assignment, refer to the user's manual (Function Explanation, Program Fundamentals) for the CPU module
used.

5
Memo

CONTENTS
6
CONTENTS
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CONDITIONS OF USE FOR THE PRODUCT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
RELEVANT MANUALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
HOW TO USE THIS MANUAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
CHAPTER 1 OVERVIEW 11
1.1 Programmable Controller Monitoring via Internet Using Web Function . . . . . . . . . . . . . . . . . . 11
1.2 Access Function to Programmable Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3 Availability of Communication Library and Sample Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4 Utilizing Web Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.5 Remote Password Check Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CHAPTER 2 SYSTEM CONFIGURATIONS 15
2.1 System Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Precautions for Using Web Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
CHAPTER 3 OPERATING PROCEDURE 19
3.1 General Procedure up to Communication Using Web Function . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2 How to Obtain and Set Up Communication Library and Sample Screen . . . . . . . . . . . . . . . . . 21
CHAPTER 4 VERIFYING OPERATION OF WEB FUNCTION USING SAMPLE SCREEN
24
4.1 Web Function Items Available on Sample Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2 Operating Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.3 Explanation of Sample Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
4.4 Example of Data Communication on Sample Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.4.1 Device Read/Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
4.4.2 Remote RUN/STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
4.4.3 Data Request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
4.4.4 Proxy Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
4.5 Configurations of Files on Sample Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
CHAPTER 5 EXAMPLE OF CREATING FILE FOR ACCESSING PROGRAMMABLE
CONTROLLER 42
5.1 Configuration of User-Created Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
5.2 File Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.3 File Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

7
CHAPTER 6 COMMUNICATION LIBRARY FUNCTIONS 52
6.1 List of Supported Communication Library Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
6.2 Communication Library Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
6.3 Arguments Used by Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
6.4 Return Values of Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
INDEX 58
REVISIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
TRADEMARKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

8
RELEVANT MANUALS
The manuals related to this product are listed below.
Order each manual as needed, referring to the following lists.
Manual name Manual number
(Model code)
Q Corresponding Ethernet Interface Module User's Manual (Basic)
Specifications, procedures for data communication with external devices, line connection (open/close), fixed buffer
communication, random access buffer communication, and troubleshooting of the Ethernet interface module
(Sold separately)
SH-080009
(13JL88)
MELSEC-L Ethernet Interface Module User's Manual (Basic)
Specifications, procedures for data communication with external devices, line connection (open/close), fixed buffer
communication, random access buffer communication, and troubleshooting of the Ethernet interface module
(Sold separately)
SH081105ENG
(13JZ73)
MELSEC-Q/L Ethernet Interface Module User's Manual (Application)
E-mail function, communication via MELSECNET/H or MELSECNET/10, communication using the data link instructions, and
file transfer function (FTP server) of the Ethernet interface module
(Sold separately)
SH-080010
(13JL89)
MELSEC Communication Protocol Reference Manual
Details of MELSEC communication protocol (MC protocol) that is used for data communication between a target device and a
CPU module
(Sold separately)
SH-080008
(13JF89)

9
HOW TO USE THIS MANUAL
Please refer to the applicable items of this manual by referring to the following outline of the contents of this manual:
(1) To find out how to use the Web function and to learn about the operating
environment
• Chapter 1 describes an overview of the Web function.
• Chapter 2 describes a system configuration for utilizing the Web function.
(2) To find out about the procedure for using the Web function
• Section 3.1 describes the procedure up to communication using the Web function.
• Section 3.2 describes how to obtain and set up the communication library and sample screen.
• Section 4.2 describes the procedure for accessing the programmable controller using a sample screen.
(3) To check the operation of the Web function
Chapter 4 describes an example when accessing the programmable controller using a sample screen.
(4) To create data used to access the programmable controller by the user
• Section 4.5 describes an overview of ASP (Active Server Pages) files for accessing the programmable
controller, as well as HTML (Hyper Text Markup Language) files to be displayed by the Web browser, both of
which are to be created by the user.
• Chapter 5 describes an example of file creation for programmable controller access.
• Chapter 6 describes the communication library functions.

10
TERMS
Unless otherwise specified, this manual uses the following generic terms and abbreviations to describe QJ71E71-100,
QJ71E71-B5 and QJ71E71-B2, and LJ71-100 Ethernet Interface Modules.
Term Description
ASP Abbreviation for Active Server Pages
CPU module A generic term for QCPU and LCPU
Ethernet module The abbreviation for Model QJ71E71-100, QJ71E71-B5 and QJ71E71-B2 Ethernet interface modules
External device Generic term for personal computers, computers, workstations and Ethernet module etc. that are connected by the
Ethernet for data communication
HTML Abbreviation for Hyper Text Markup Language.
HTTP Abbreviation for Hyper Text Transfer Protocol.
This protocol sends/receives the information on World Wide Web in the Internet.
LCPU The abbreviation for the MELSEC-L series CPU module
MC protocol
Abbreviation for MELSEC communication Protocol.
This protocol is used to access MC protocol supporting modules, such as the serial communication module and Ethernet
module, or programmable controllers connected to MC protocol supporting modules from external devices.
Programming tool A generic term for GX Works2 and GX Developer
QCPU A generic term for the Basic model QCPU, High Performance model QCPU, Process CPU, Redundant CPU, and
Universal model QCPU
Reference Manual The abbreviation for the MELSEC Communication Protocol Reference Manual
URL Abbreviation for Uniform Resource Locator.
User's Manual (Application) The abbreviation for the MELSEC-Q/L Ethernet Interface Module User's Manual (Application)
User's Manual (Basic) The abbreviation for the Q Corresponding Ethernet Interface Module Use's Manual (Basic) and the MELSEC-L Ethernet
Interface Module User's Manual (Basic)
User's Manual (Web function) The abbreviation for the MELSEC-Q/L Ethernet Interface Module Use's Manual (Web function)
Web browsers Abbreviation for software that views Web pages.
Web server Abbreviation for the computer in which Web server software operates.
Web server software Generic name of server software that supports the WWW (World Wide Web) services.

11
CHAPTER 1 OVERVIEW
1
1.1 Programmable Controller Monitoring via Internet Using Web Function
CHAPTER 1 OVERVIEW
The following shows an overview of the Web function with the Ethernet module.
1.1 Programmable Controller Monitoring via Internet Using
Web Function
The Web function with the Ethernet module is used for the system administrator to monitor the MELSEC-Q/L series
CPU modules at a remote location via the Internet, using a Web browser.
Web server
Internet
service provider
Internet network
(Public line)
Internet
service provider
External devices (Web browsers)
Ethernet module
Router

12
1.2 Access Function to Programmable Controller
By using the Web function, the programmable controller data can be collected or updated, the CPU module operation
can be monitored, and the status control of the CPU module can be performed in order to control and monitor the
equipment on the programmable controller side using a Web browser.*1
*1 With the Web function, exchange of information between the Ethernet module and the Web server, and between the
Web server and the Web browser is performed via HTTP.
With the Web function, the programmable controller is accessed by sending/receiving messages of the MC protocol,
which are used for communication between the programmable controller and the external device, via HTTP.
1.3 Availability of Communication Library and Sample
Screen
(1) The Web function can be used by installing the following:
(2) A sample screen (HTML files, ASP files) is provided. It is used to check the
access function to the programmable controller using the communication
library and the Web function. Contact your local agency or marketing
company.
(a) The user can easily create ASP files in order to access the programmable controller
by using the communication library.
In addition, the result of access to the programmable controller using ASP files can arbitrarily be displayed on
the Web browser using user-created HTML files.
Classification Required device/software Description
Programmable controller side Ethernet module Subject module of this manual
Server computer
(Web server)
Web server Page 16, Section 2.1 (4)
Communication library Page 12, Section 1.3 (2)
ASP files Files created by the user to be used for accessing
the programmable controller
HTML files Files created by the user to be used for displaying
the Web browser
Device on the Web browser side Web browser Page 16, Section 2.1 (4)
HTTP
HTML
ASP
Web server External device
Display of
requests/results
Web browser
Ethernet module
Execution
of the ASP file
Communication
library
HTTP
header
MC protocol
(Command message)
MC protocol
(Response message)
HTTP
header

13
CHAPTER 1 OVERVIEW
1
1.4 Utilizing Web Server
(b) Device memory read/write, remote RUN/STOP and other operations can be
performed for the Q/LCPU of an Ethernet module mounted station by specifying the
URL of the sample screen using the Web browser.*1
*1 The execution result is displayed by simply entering the access device, the number of devices, etc. in the items to be
displayed in the Web browser.
Ex.
To read four points of data registers D0 = 1234H, D1 = 5678H, D2 = 9ABCH, and D3 = 1234H.
1.4 Utilizing Web Server
Access to the programmable controller using the Web function becomes possible by combining an Ethernet module
and a Web server computer.
(1) A system can easily be configured by utilizing a Web server.
(a) Complicated screens can be created.
The user can create multiple HTML files and HTML files of large sizes without being limited by the size of the
Ethernet module memory by storing these HTML files in a Web server.*1
*1 The HTML files for Web browser can be created or changed easily if the user has knowledge of creating a web page.
(b) Reducing the load on the Ethernet module
Since access programs for the programmable controller and control programs for Web browsers are executed
in the Web server, the load on the Ethernet module can be minimized when accessing the programmable
controller.
(c) Separating an Ethernet line
By separating the line connecting between the Ethernet module and the Web server, and the line between the
Web server and the Web browser, the screen data for the Web browser will not be sent to the line connecting
between the Ethernet module and the Web server.
Therefore, it is possible to reduce effect on the transmission/reception of data for system control for
communication between the Ethernet module and the external device.
(Input screen) (Execution result screen)

14
(2) System expansion can easily be achieved because the Web server and the
Ethernet module are separated.
For example, the following function can be added:
If it is necessary to maintain the security of the programmable controller system against any unauthorized access
(to damage programs or data, etc.) from external devices, the user can take a measure by adding a firewall
function to the Web server.
(3) The communication information between the Ethernet module and the Web
server, and between the Web server and the Web browser can be recorded and
used for maintenance using the functions of the Web server.
1.5 Remote Password Check Function
(1) The remote password check function of the Ethernet module is provided to
prevent any unauthorized access to the Q/LCPU by the user at a remote
location.
For details on the remote password check function, refer to the user's manual (Basic).
(2) If the HTTP port is set as the target connection for remote password check,
access to the Q/LCPU will become possible by performing unlock processing
of the remote password via the dialog box displayed in the Web browser.
The remote password lock processing is performed when the Web browser ends.

15
CHAPTER 2 SYSTEM CONFIGURATIONS
2
2.1 System Configurations
CHAPTER 2 SYSTEM CONFIGURATIONS
2.1 System Configurations
This section explains the environment and system configurations for using the Web function.
The following describes the system configurations for using the Web function of the Ethernet module.
(1) System configuration when accessing via the Internet
*1 Page 16, Section 2.1 (4)
*2 Page 16, Section 2.1 (3)
Internet network
(public line)
Firewall
<Factory/production site>
Ethernet module
*2
Internet
service provider
Router
Ethernet
Router
Web browser
*1
Commercially sold product
Web server
*1
Commercially sold product
HTML files for Web browser
ASP files for programmable
controller access
Files
Created by the user
Communication library (DLL)
Sample screen (HTML, ASP)
Files
Provided by
Mitsubishi Electric Corporation
Ethernet
<System administrator>
External device
Internet
service provider

16
(2) System configuration when accessing via the Intranet
*1 Page 16, Section 2.1 (3)
*2 Page 16, Section 2.1 (4)
(3) Ethernet module
The Ethernet module that can use the Web function is as follows:
• Model QJ71E71-100 Ethernet interface module
• Model QJ71E71-B5 Ethernet interface module
• Model QJ71E71-B2 Ethernet interface module
• Model LJ71E71-100 Ethernet interface module
For the applicable systems and the devices required for network configuration of the above Ethernet module,
refer to the user's manual (Basic).
(4) Web server and Web browser
The operating environment of the Web server is listed below.
(a) The following files need to set up in the Web server to use the Web function.
• Communication library
• HTML files for Web browser
• ASP files for programmable controller access
Item Operating environment
Web Server
Internet Information Services 5.1 by MicrosoftCorporation
Internet Information Services 7.5 by MicrosoftCorporation
Internet Information Services 8.0 by MicrosoftCorporation
Web browser Internet Explorer 8.0 or later version by MicrosoftCorporation
Ethernet
Ethernet module
*1
Web browser
*2
Commercially sold product
Web server
*2
Commercially sold product
HTML files for Web browser
ASP files for programmable
controller access
Files
Created by the user
Communication library (DLL)
Sample screen (HTML, ASP)
Files
Provided by
Mitsubishi Electric Corporation
External device

17
CHAPTER 2 SYSTEM CONFIGURATIONS
2
2.2 Precautions for Using Web Function
2.2 Precautions for Using Web Function
(1) Precautions for configuring a system
(a) It is necessary to take sufficient security measures for connection to the Internet.
Consult with a network installer, an Internet service provider, and a network administrator (person in charge of
network planning and IP address management).
Mitsubishi Electric Corporation will not take any responsibility for any system problems that may occur while
connecting to the Internet.
(b) If a firewall function is installed in the network, set it so that the HTTP protocol can
pass the firewall function.
(c) When accessing multiple Ethernet modules via one Web server, the next process
may not be executed during the time from the request start through until the
response is returned.
If no response is received due to a communication line fault, the next processing may be delayed until a
timeout occurs on the Web server.
Ex.
Accessing 2 Ethernet modules using one Web server
• Access from Web browser 1) to Ethernet module 1)
• Access from Web browser 2) to Ethernet module 2)
The line fault between the Web server and Ethernet module 1) disables the response from Ethernet module 1)
to the Web server. This brings the Web server into the wait status and the access request from Web browser 2)
to Ethernet module 2) has to wait at the Web server.
Web server Response to
Web server
Because no response is received
from Ethernet module 1), the next
request cannot be handled.
Ethernet module 1)
Line fault
Intranet
Web browser 1)
Web browser 2) Ethernet module 2)
Internet

18
(2) Precautions relating to security
The remote password check function is not designed to completely prevent unauthorized access.
When accessing a CPU module via the Internet, and if it is necessary to maintain the security of the
programmable controller system, the user should take appropriate measures.
Mitsubishi Electric Corporation will not take any responsibility for any system problems that may occur due to
unauthorized access.
Examples of measures against unauthorized access
• Installing a firewall function
• Security measures by the Web server
Take necessary measures by referring to the User's Manual of the device used.
(3) Precautions for accessing the CPU module
(a) When the user creates an ASP or HTML file for the Web function, use the
communication library (QeAccess.dll) provided by Mitsubishi Electric Corporation.
The communication library cannot be created by the user.
For details on the communication library functions, refer to Page 52, CHAPTER 6.
(b) The Web server provides a log function that records file access, etc. Periodically
collect the access log for the programmable controller access file, and check the
access status.
If there are too many unauthorized access logs to the Web server, the user should take appropriate measures
to resolve unauthorized access.
(c) A maximum of four connections are allowed as the simultaneous access count
when accessing the Ethernet module using the Web function.
If this maximum allowable access number is exceeded, a timeout error will be returned from a communication
library function.
In case a timeout error occurs, extend the access interval time and retry.