Mitsubishi Electric LCPU-U-HW Instruction Manual

Thank you for purchasing the Mitsubishi Electric programmable
controller MELSEC-L series.
© 2009 MITSUBISHI ELECTRIC CORPORATION
Safety Guidelines
Prior to use, please read this and relevant manuals thoroughly to
fully understand the product.
MODEL LCPU-U-HW
MODEL
CODE 13J240
IB(NA)-0800456-P(1806)MEE

1
SAFETY PRECAUTIONS
(Read these precautions before using this product.)
Before using the MELSEC-L series products, please read this manual and the
relevant manuals carefully and pay full attention to safety to handle the product
correctly. When equipment is used by the way a maker doesn't designate, the
protection of the equipment may be damaged.
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.
[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.
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
(2) Machine OPR (Original Point Return) of the CPU module’s positioning
function is controlled with 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.
(3) When the CPU module detects an error during operation of the CPU
module’s positioning function, the motion slows down and stops.
(4) 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 CPU 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 CPU 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.
(5) 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.
●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.

3
[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.
●When changing data of a running programmable controller from a peripheral
connected to the CPU module or from an external device such as a personal
computer connected to an intelligent function module, configure an interlock
circuit in the program to ensure that the entire system will always operate
safely.
For other controls to a running programmable controller (such as 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 program, and determine corrective actions
to be taken between the external device and CPU module in case of a
communication failure.
●An absolute position return by the CPU module’s positioning function may turn
off the servo-on signal (servo off) for approximately 20ms, and the motor may
run unexpectedly. If this causes a problem, provide an electromagnetic brake
separately to lock the motor during absolute position return.
●Do not write any data to the "system area" or "write-protect area" (R) of the
buffer memory in an intelligent function module.
Also, do not turn on any “use prohibited” signal that is output from the CPU
module to the intelligent function module.
Doing so may cause malfunction of the programmable controller system.
●When setting auto refresh parameters, specify "Y" for the remote output RY
refresh devices. Specifying any other than "Y" (for example, M or L) will hold
the previous device status in the case of a CPU stop. For information on how
to stop the data link, refer to the MELSEC-L CC-Link System Master/Local
Module User's Manual.
●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) 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 module detects an error, the motion slows down and stops or the
motion suddenly stops, depending on the stop group setting in parameter.
Set the parameter according to the positioning system specifications. In
addition, set the OPR parameter 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 transistor in an output circuit,
where the CPU 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 function may turn off the
servo-on signal (servo off) for approximately 60ms + scan time, 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]
[Design Precautions]
WARNING
Precautions for using flexible high-speed I/O control
modules
●When changing setting data and operating status of the running module from
a personal computer, configure an interlock circuit external to the
programmable controller to ensure that the entire system operates safely.
In addition, before performing online operations for the running module from a
personal computer, determine corrective actions to be taken in case of a
communication failure due to poor contact of cables.
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.
●Time from when the CPU module is powered on or is reset to when it enters in
RUN status depends on the system configuration, parameter settings, and
program size. Design the program 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.

6
[Design Precautions]
[Installation Precautions]
CAUTION
Precautions for using digital-analog converter modules
and analog input/output modules
●At power-on, a voltage may occur or a current may flow between output
terminals for a moment. In this case, start the control after analog outputs
become stable.
●Power on or off the external power supply while the programmable controller
is on. Failure to do so may result in 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.
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.

7
[Installation Precautions]
[Wiring Precautions]
CAUTION
●Use the programmable controller 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.
●Do not directly touch any conductive part of the module. Doing so can cause
malfunction or failure of the module.
●Securely connect an extension cable to the connectors of a branch module
and an extension module. After connection, check that the cable is inserted
completely. Poor contact may cause malfunction.
●Securely install the SD memory card pushing the card into the SD memory
card installation slot. After installation, check that the SD memory card is
installed completely. Poor contact may cause malfunction.
●Keep in mind that there is a possibility that the unit is high temperature, during
turning on electricity and immediately after power supply interception.
●Do not directly touch any conductive part and electronic components of the
module and the SD memory card. Doing so can cause malfunction and failure
of the module and the SD memory card.
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 the differential receiver of a
drive unit, connect a high-speed output common terminal to the common
terminal of the differential receiver 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.

8
[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 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.
●Prevent foreign matter such as dust or wire chips from entering the module.
Such foreign matter can cause a fire, failure, or malfunction.

9
[Wiring Precautions]
CAUTION
●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.
●For the CC-Link system, use dedicated cables that are specified by the
manufacturer. If any other cable is used, performance of the CC-Link system
is not guaranteed. Also, the maximum overall cable length and the station-to-
station cable length must meet those specified in the MELSEC-L CC-Link
System Master/Local Module User’s Manual. If not, normal data
communication is not guaranteed.
●To use the high-speed counter function of the CPU module, ground the
shielded cable to the encoder (relay box). Failure to do so may cause
malfunction.
●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
who is familiar with protection against electric shock.
For wiring methods, refer to the MELSEC-L CPU Module User's Manual
(Hardware Design, Maintenance and Inspection).
Precautions for using high-speed counter modules
●Ground the shield cable on the encoder side (relay box). Always ground the
FG and LG terminals to the protective ground conductor. Failure to do so may
cause malfunction.
Precautions for using CC-Link/LT master module
●For the CC-Link/LT, use the cables specified by the CC-Link Partner
Association. The performance of the CC-Link/LT cannot be assured if any
other cables than the specified are used. For the network wiring, follow the
specifications described in MELSEC-L CC-Link/LT Master Module User's
Manual. Normal data communication is not guaranteed if the wiring is not
conducted according to the specifications.