Mitsubishi Electric MELSEC LJ72GF15-T2-U-HW Instruction Manual

Thank you for purchasing the Mitsubishi programmable controller
MELSEC-L series.
© 2010 MITSUBISHI ELECTRIC CORPORATION
Safety Guidelines
Prior to use, please read this and relevant manuals thoroughly to
fully understand the product.
MODEL LJ72GF15-T2-U-HW
MODEL
CODE 13J241
IB(NA)-0800455-L(2110)MEE

1
SAFETY PRECAUTIONS
(Read these precautions before using this product.)
Before using the MELSEC-L series 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.
All safety precautions for the MELSEC-L series products are described in this
manual.
WARNING 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.
CAUTION

2
[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. Incorrect output or malfunction
due to a communication failure may result in an accident.
(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 the output status is as follows:
• If the overcurrent or overvoltage protection of the power supply
module is activated, all outputs are turned off.
• If the self-diagnostics function of the head module detects an error
such as a watchdog timer error, all outputs are held unchanged or
turned off according to the parameter setting.
All outputs may turn 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 "GENERAL SAFETY REQUIREMENTS" in this manual.
(3) Outputs may remain on or off due to a failure of an output circuit relay or
transistor. Configure an external circuit for monitoring output signals that
could cause a serious accident.
●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.

3
[Design Precautions]
WARNING
●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 the network. Failure to do so may result in an accident
due to an incorrect output or malfunction.
●When changing data of a running programmable controller from a peripheral
connected to the head module or from an external device such as a personal
computer connected to an intelligent function module, configure an interlock
circuit in the master station program to ensure that the entire system will
always operate safely.
For other controls to a running programmable controller (such as master
station program modification or operating status change), read relevant
manuals carefully and ensure the safety before the operation.
Especially, in the case of a control from an external device to a remote
programmable controller, immediate action cannot be taken for a problem on
the programmable controller due to a communication failure. To prevent this,
configure an interlock circuit in the master station program, and determine
corrective actions to be taken between the external device and head module
in case of a communication failure.
●Do not write any data to the "system area" or "write-protect area" of the buffer
memory in an intelligent function module.
Also, do not turn on any "use prohibited" signal that is output from the head
module to the intelligent function module.
Doing so may cause malfunction of the programmable controller system.
●Disconnection of a communication cable (such as a CC-Link dedicated cable)
may make the line condition unstable, causing communication errors on
multiple stations on the network. Configure an interlock circuit in the program
so that the system will operate safely even if these communication errors
occur on multiple stations. Failure to do so may result in an accident due to an
incorrect output or malfunction.

4
[Design Precautions]
WARNING
Precautions for using digital-analog converter modules
and analog input/output modules
●When a module is faulty, analog outputs may remain on. Configure an
external circuit for monitoring output signals that could cause a serious
accident.
Precautions for using high-speed counter modules and
flexible high-speed I/O control modules
●Outputs may remain on or off due to a failure of a transistor for external
output. Configure an external circuit for monitoring output signals that could
cause a serious accident.
Precautions for using positioning modules
●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. Incorrect output or malfunction
due to a communication failure may result in an accident.
(1) Machine OPR (Original Point Return) of the positioning module is
controlled by two kinds of data: an OPR direction and an OPR speed.
Deceleration starts when the near-point watchdog signal turns on. If an
incorrect OPR direction is set, motion control may continue without
deceleration. To prevent machine damage caused by this, configure an
interlock circuit external to the programmable controller.
(2) When the head module detects an error, the motion slows down to stop or
suddenly stops, depending on the stop group parameter setting. Set
parameters according to the positioning system specifications. Also, set
the OPR parameters and positioning data within the parameter setting
range.
(3) Outputs may remain on or off, or be undefined due to a failure of a
component such as an insulated element or a transistor in an output
circuit, where the head module cannot detect any error. Configure an
external circuit for monitoring output signals in a system where an
incorrect output could cause a serious accident.
●An absolute position restoration by the positioning module may turn off the
servo-on signal (servo off) for approximately 60ms, and the motor may run
unexpectedly. If this causes a problem, provide an electromagnetic brake to
lock the motor during absolute position restoration.

5
[Design Precautions]
WARNING
Precautions for using flexible high-speed I/O control
modules
●When changing data and operating status of the running module from an
external device such as a personal computer connected, configure an
interlock circuit external to the programmable controller to ensure that the
entire system always operates safely.
In addition, before performing online operations, determine corrective actions
to be taken between the external device and the module in case of a
communication failure due to poor contact of cables.

6
[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.
●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.
Precautions for using dual channel isolated high
resolution analog-digital converter modules
●Do not install the analog signal cable together with main circuit lines, power
cables, or load circuit lines of a device other than the programmable
controller. Install the analog output cable 150mm away from the above lines
and cables. Failure to do so may result in malfunction due to noise.
Precautions for using digital-analog converter modules
and analog input/output modules
●When the system is powered on, a surge voltage may occur or inrush current
may flow between output terminals. Start the control after analog outputs are
stabilized.
●Turn on or off the external power supply while the programmable controller is
on. Doing so with the programmable controller is off may cause incorrect
output or malfunction.
Precautions for using flexible high-speed I/O control
modules
●Do not install the control lines or communication cables together with the
main circuit lines or power cables. Keep a distance of 150mm or more
between them. Failure to do so may result in malfunction due to noise.

7
[Security Precautions]
[Installation Precautions]
[Installation Precautions]
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.
WARNING
●Shut off the external power supply for the system in all phases before
mounting or removing the 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
described 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.
●Tighten the screw within the specified torque range. Undertightening can
cause drop, short circuit or malfunction. Overtightening can damage the screw
and/or module, resulting in drop, short circuit, or malfunction.
●Do not directly touch any conductive part and electronic components of the
module. Doing so can cause malfunction or failure of the module.

8
[Wiring Precautions]
WARNING
●Shut off the external power supply for the system in all phases 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 product
before turning it on for operation. Failure to do so may result in electric shock.
Precautions for using flexible high-speed I/O control
modules
●When connecting a differential output terminal to a differential receiver of a
drive unit, connect the high-speed output common terminal to the differential
receiver common terminal of the drive unit. Failure to do so may cause the
module to fail or malfunction because of the potential difference that occurs
between the high-speed output common terminal and the differential receiver
common terminal.

9
[Wiring Precautions]
CAUTION
●Ground the FG and LG terminals to the protective ground conductor
dedicated to the programmable controller. 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 screw on the terminal block 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 device connection must be crimped or pressed with
the tool specified by the manufacturer, or must be correctly soldered.
Incomplete connections could result in short circuit, fire, or malfunction.
●Connect the connector to the module securely.
●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 cables may swing or inadvertently be pulled, resulting in
damage to the module or cables or malfunction due to poor connection.
●Confirm the interface type in advance and connect the cable correctly.
Connecting a cable to a different interface or incorrect wiring will cause failure
of the module and the external device.
●Tighten the screws on the terminal block within the specified torque range.
Undertightening can cause short circuit or malfunction. Overtightening can
damage the screw and/or module, resulting in drop, short circuit, fire, or
malfunction.
●When disconnecting the communication cable from the module, do not pull
the cable by the cable part.
For a cable with connector, hold the connector by hand and pull it out. For a
cable connected to a terminal block, loosen the terminal block screws first
before removing the cable.
Failure to do so may result in malfunction and damage to the module or cable.