Mitsubishi Electric MELSEC-L SSCNETIII/H User manual

MELSEC-L SSCNET/H Head Module
User's Manual
-LJ72MS15

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.
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
●Configure safety circuits external to the programmable controller to ensure that the entire system
operates safely even when a fault occurs in the external power supply or the programmable controller.
Failure to do so may result in an accident due to an incorrect output or malfunction.
(1) Emergency stop circuits, protection circuits, and protective interlock circuits for conflicting
operations (such as forward/reverse rotations or upper/lower limit positioning) must be configured
external to the programmable controller.
(2) When the programmable controller detects an abnormal condition, it stops the operation and all
outputs are:
• Turned off if the overcurrent or overvoltage protection of the power supply module is activated.
• Held or turned off according to the parameter setting if the self-diagnostic function of the head
module detects an error such as a watchdog timer error.
Also, all outputs may be turned on if an error occurs in a part, such as an I/O control part, where
the head module cannot detect any error. To ensure safety operation in such a case, provide a
safety mechanism or a fail-safe circuit external to the programmable controller. For a fail-safe
circuit example, refer to Page 134, Appendix 9.
(3) Outputs may remain on or off due to a failure of a component such as a relay and transistor in an
output circuit. Configure an external circuit for monitoring output signals that could cause a
serious accident.
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]
WARNING
●In an output circuit, when a load current exceeding the rated current or an overcurrent caused by a
load short-circuit flows for a long time, it may cause smoke and fire. To prevent this, configure an
external safety circuit, such as a fuse.
●Configure a circuit so that the programmable controller is turned on first and then the external power
supply. If the external power supply is turned on first, an accident may occur due to an incorrect output
or malfunction.
●Configure a circuit so that the external power supply is turned off first and then the programmable
controller. If the programmable controller is turned off first, an accident may occur due to an incorrect
output or malfunction.
●For the operating status of each station after a communication failure, refer to relevant manuals for
each network. Incorrect output or malfunction due to a communication failure may result in an
accident.
●When connecting a peripheral with the head 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 of the Motion controller to ensure that the entire
system will always operate safely.
For other controls to a running programmable controller (such as program modification of the Motion
controller or operating status change), read relevant manuals carefully and ensure the safety before
the 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 program of the Motion
controller, and determine corrective actions to be taken between the external device and head module
in case of a communication failure.
●The optical transmitter and receiver of the head module use laser diodes (class 1 in accordance with
IEC 60825-1). Do not look directly at a laser beam. Doing so may harm your eyes.
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.
●During control of an inductive load such as a lamp, heater, or solenoid valve, a large current
(approximately ten times greater than normal) may flow when the output is turned from off to on.
Therefore, use a module that has a sufficient current rating.
●After the head module is powered on or is reset, the time taken to enter the RUN status varies
depending on the system configuration and/or parameter settings. Design circuits so that the entire
system will always operate safely, regardless of the time.

3
[Installation Precautions]
[Installation Precautions]
[Wiring Precautions]
WARNING
●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 electric shock or cause the module to fail or malfunction.
CAUTION
●Use the head module in an environment that meets the general specifications in this manual. Failure
to do so may result in electric shock, fire, malfunction, or damage to or deterioration of the product.
●To interconnect modules, engage the respective connectors and securely lock the module joint levers
until they click. Incorrect interconnection may cause malfunction, failure, or drop of the module.
●Do not directly touch any conductive parts and electronic components of the module. Doing so can
cause malfunction or failure of the module.
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 cause the module to fail or malfunction.
●After installation and wiring, attach the included terminal cover to the module before turning it on for
operation. Failure to do so may result in electric shock.

4
[Wiring Precautions]
CAUTION
●Individually ground the FG and LG terminals of the programmable controller with a ground resistance
of 100 ohms or less. Failure to do so may result in electric shock or malfunction.
●Use applicable solderless terminals and tighten them within the specified torque range. If any spade
solderless terminal is used, it may be disconnected when a terminal block screw comes loose,
resulting in failure.
●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.
●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.
●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.
●Place the cables in a duct or clamp them. If not, dangling cable may swing or inadvertently be pulled,
resulting in damage to the module or cables or malfunction due to poor contact.
●Check the interface type and correctly connect the cable. Incorrect wiring (connecting the cable to an
incorrect interface) may cause failure of the module and external device.
●Tighten the terminal block screws within the specified torque range. Undertightening can cause short
circuit, fire, or malfunction. Overtightening can damage the screw and/or module, resulting in drop,
short circuit, fire, or malfunction.
●When disconnecting the cable from the module, do not pull the cable by the cable part. For the cable
with connector, hold the connector part of the cable. For the cable connected to the terminal block,
loosen the terminal screw. Pulling the cable connected to the module may result in malfunction or
damage to the module or cable.
●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.
●Mitsubishi Electric programmable controllers must be installed in control panels. Connect the main
power supply to the power supply module in the control panel through a relay terminal block. Wiring
and replacement of a power supply module must be performed by qualified maintenance personnel
with knowledge of protection against electric shock. For wiring methods, refer to the MELSEC-L CPU
Module User's Manual (Hardware Design, Maintenance and Inspection).

5
[Startup and Maintenance Precautions]
[Startup and Maintenance Precautions]
[Disposal Precautions]
WARNING
●Do not touch any terminal while power is on. Doing so will cause electric shock or malfunction.
●Shut off the external power supply (all phases) used in the system before cleaning the module or
retightening the terminal block screws. Failure to do so may result in electric shock.
CAUTION
●Before performing online operations (especially, program modification of the Motion controller, forced
output, and operation status change) for the running head module from the peripheral device
connected, read relevant manuals carefully and ensure the safety. Improper operation may damage
machines or cause accidents.
●Do not disassemble or modify the module. 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.
●Tighten the terminal block screws within the specified torque range. Undertightening can cause drop
of the component or wire, short circuit, or malfunction. Overtightening can damage the screw and/or
module, resulting in drop, short circuit, or malfunction.
●After the first use of the product (module and terminal block), do not connect/disconnect the product
more than 50 times (in accordance with IEC 61131-2). Exceeding the limit may cause malfunction.
●Before handling the module, touch a conducting object such as a grounded metal to discharge the
static electricity from the human body. Failure to do so may cause the module to fail or malfunction.
CAUTION
●When disposing of this product, treat it as industrial waste.

6
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.

7
INTRODUCTION
Thank you for purchasing the Mitsubishi Electric MELSEC-L series programmable controllers.
This manual describes the operating procedure, system configuration, parameter setting, functions, and
troubleshooting of the SSCNET III/H head module (hereafter abbreviated as head 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-L series programmable controller to handle the product correctly.

8
RELEVANT MANUALS
(1) Motion controller relevant manuals
For Motion controllers, refer to the following.
(2) Operating manual
Manual name
<manual number (model code)> Description
Q173D(S)CPU/Q172D(S)CPU Motion controller User's Manual
<IB-0300133, 1XB927>
Specifications of the Motion CPU modules, Q172DLX servo external signal
interface module, Q172DEX synchronous encoder interface module,
Q173DPX manual pulse generator interface module, power supply modules,
servo amplifiers, SSCNET III cables, and serial absolute synchronous
encoder cables
Q170MSCPU Motion controller User's Manual
<IB-0300212, 1XB962>
Specifications of the Q170MSCPU Motion controller, Q172DLX servo external
signal interface module, Q173DPX manual pulse generator interface module,
servo amplifiers, and SSCNET III cables; system maintenance and inspection;
and troubleshooting
Q173D(S)CPU/Q172D(S)CPU Motion controller Programming Manual
(COMMON)
<IB-0300134, 1XB928>
Multiple CPU system configuration, performance specifications, common
parameters, auxiliary and applied functions, and error lists
Q173D(S)CPU/Q172D(S)CPU Motion controller (SV13/SV22) Programming
Manual (Motion SFC)
<IB-0300135, 1XB929>
Functions, programming, debugging, and error lists of Motion SFC programs
Manual name
<manual number (model code)> Description
GX Works2 Version 1 Operating Manual (Common)
<SH-080779ENG, 13JU63>
System configuration, parameter settings, and online operations of GX
Works2, which are common to Simple projects and Structured projects

9
Memo

CONTENTS
10
CONTENTS
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
CONDITIONS OF USE FOR THE PRODUCT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
RELEVANT MANUALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
MANUAL PAGE ORGANIZATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
TERM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
PACKING LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
CHAPTER 1 HEAD MODULE 16
CHAPTER 2 PART NAMES 20
CHAPTER 3 SPECIFICATIONS 24
3.1 General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2 Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3 Function List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
CHAPTER 4 PROCEDURES BEFORE OPERATION 29
CHAPTER 5 SYSTEM CONFIGURATION 31
5.1 Head Module System Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2 Applicable Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
CHAPTER 6 INSTALLATION AND WIRING 35
6.1 Wiring Environment and Installation Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.1.1 Installation environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
6.1.2 Installation position. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
6.2 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
6.2.1 Connecting modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
6.2.2 Mounting the modules on a DIN rail. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
6.2.3 Changing modules on a DIN rail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
6.3 Wiring to the Power Supply Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.4 Testing the Head Module Before Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.5 Wiring to the Head Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.5.1 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
6.5.2 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
6.5.3 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
CHAPTER 7 PARAMETER SETTING 53
7.1 PLC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.2 Intelligent Function Module Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

11
CHAPTER 8 CYCLIC TRANSMISSION 65
8.1 Cyclic Transmission of Bit Device Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
8.2 Cyclic Transmission of Word Device Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
CHAPTER 9 SSCNET III COMMUNICATION CONDITION MONITOR 77
CHAPTER 10 MAINTENANCE AND INSPECTION 81
10.1 Daily Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
10.2 Periodic Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
CHAPTER 11 TROUBLESHOOTING 83
11.1 Before Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
11.2 Troubleshooting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
11.3 System Error History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
11.4 Checking the LEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
11.5 Troubleshooting by Symptom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
11.5.1 Cyclic transmission cannot be performed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
11.5.2 Transient transmission cannot be performed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
11.6 Error Code List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
APPENDICES 101
Appendix 1 Forced On/Off for External I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Appendix 2 Remote Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Appendix 3 END Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Appendix 4 Link Special Relay (SB) List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Appendix 5 Link Special Register (SW) List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Appendix 6 Special Relay (SM) List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Appendix 7 Special Register (SD) List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Appendix 8 EMC and Low Voltage Directives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Appendix 8.1 Requirements for compliance with the EMC Directive . . . . . . . . . . . . . . . . . . . . . . . .124
Appendix 8.2 Requirements for compliance with the Low Voltage Directive . . . . . . . . . . . . . . . . . .132
Appendix 9 General Safety Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Appendix 10Calculating Heating Value of Programmable Controller . . . . . . . . . . . . . . . . . . . . . . . . 136
Appendix 10.1 Calculating the average power consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136
Appendix 11 Processing Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Appendix 12Checking Serial Number and Function Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Appendix 13External Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
INDEX 146
REVISIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
TRADEMARKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

12
MANUAL PAGE ORGANIZATION
In this manual, pages are organized and the symbols are used as shown below.
The following illustration is for explanation purpose only, and should not be referred to as an actual documentation.
*1 The mouse operation example (for GX Works2) is provided below.
The section of
the current page is shown.
The chapter of
the current page is shown.
"" is used for
screen names and items.
[ ] is used for items
in the menu bar and
the project window.
shows operating
procedures.
shows reference
manuals.
shows notes that
requires attention.
shows mouse
operations.
*1
shows
reference pages.
shows setting or
operating examples.
Ex.
shows useful
information.
A window selected in the view selection area is displayed.
View selection area
[Online] [Write to PLC...]
Select [Online] on the menu bar,
and then select [Write to PLC...].
Project window [Parameter]
[PLC Parameter]
Select [Project] from the view selection
area to open the Project window.
Menu bar
Ex.
Ex.
In the Project window, expand [Parameter] and
select [PLC Parameter].

13
TERM
Unless otherwise specified, this manual uses the following terms.
Term Description
Buffer memory A memory in an intelligent function module, where data (such as setting values and monitoring values) are stored
Cyclic transmission A function by which data are periodically exchanged among stations on the same network using link devices (RX, RY,
RWw, and RWr)
Data link A generic term for cyclic transmission and transient transmission
Dedicated instruction An instruction that simplifies programming for using functions of intelligent function modules
Device A device (X, Y, W, or others) in a head module
Disconnection A process of stopping data link if a data link error occurs
GX Works2 The product name of the software package for the MELSEC programmable controllers
Head module The abbreviation for the LJ72MS15 SSCNET III/H head module
Intelligent function module A module that has functions other than input and output, such as an A/D converter module and D/A converter module
Link device A device (RX, RY, RWr, or RWw) in a head module
Link special register (SW) Word data that indicates the operating status and data link status of a head module
Link special relay (SB) Bit data that indicates the operating status and data link status of a head module
Motion controller A generic term for the Q173DSCPU/Q172DSCPU Motion CPU module and Q170MSCPU Motion controller
MT Developer2 The product name of the MELSOFT programming software package for the Motion controllers
Parameter memory A flash ROM in a head module, where the parameters of the head module are stored
RAS The abbreviation for Reliability, Availability, and Serviceability. This term refers to usability of automated equipment.
Remote input (RX) Bit data input from a head module to a Motion controller
Remote output (RY) Bit data output from a Motion controller to a head module
Remote register (RWr) Word data input from a head module to a Motion controller
Remote register (RWw) Word data output from a Motion controller to a head module
Return A process of restarting data link when a station recovers from an error
SSCNET III/H One of the high-speed synchronous networks between a Motion controller and a servo amplifier
Transient transmission A function that enables a Motion controller to access a head module by using dedicated instructions

14
PACKING LIST
The following items are included in the package of this product. Before use, check that all the items are included.
LJ72MS15
Head module (LJ72GF15-T2) + END cover (L6EC) Safety Guidelines (IB-0800494)

15
Memo

16
CHAPTER 1 HEAD MODULE
The head module can connect MELSEC-L series I/O modules and intelligent function modules on SSCNET III/H.
The head module makes it possible to integrate systems into a single system as remote I/O modules and intelligent
function modules for a different system network can be configured. This leads to wire-saving and space-saving of the
system.
(1) Cyclic transmission
The I/O signals of a module connected to the head module can operate as those of the Motion controller. (
Page 65, CHAPTER 8)
For example, when the output (Y) of the Motion controller is turned on, the output (Y) of a module connected to
the head module turns on.
RX
RY
RWw
RWr
RX
RY
RWw
RWr
X
YY
X
Motion
controller
Head module Input module Output module Intelligent
function module
Buffer
memory
Motion controller Head module

17
CHAPTER 1 HEAD MODULE
1
(2) Transient transmission
The Motion controller can directly access the buffer memory of an intelligent function module connected to the
head module by transient transmission.
The Motion controller sends requests to the head module with dedicated instructions (Programming Manual
(Motion SFC) for the Motion controller used).
(3) Setting parameters
Parameters for the head module can be set using software, GX Works2. Creating parameter setting programs is
not required. (Page 53, CHAPTER 7)
1234H 1234 H
Device Buffer memory
Intelligent
function module
Motion controller Head module
Command
RST M0
RFROM W0,K2,H02,H10,K1,M0
M0

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(4) Diagnostics
GX Works2 and MT Developer2 facilitate diagnosing the head module and connected modules. (Page 77,
CHAPTER 9, Page 83, Section 11.2)
(a) System Monitor (GX Works2)
(b) SSCNET III Communication Condition Monitor (MT Developer2)