● 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.
● Check the rated voltage and signal 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 fire
● 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
● Securely connect the connector to the module. Poor contact may cause malfunction.
● 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 malfunction or damage to modules or cables.
In addition, the weight of the cables may put stress on modules in an environment of strong vibrations
Do not clamp the extension cables with the jacket stripped. Doing so may change the characteristics
of the cables, resulting in malfunction.
● 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 connector screws within the specified torque range. Undertightening can cause drop of
the screw, 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. 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.
● 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, refer to the MELSEC iQ-R Module Configuration Manual.
● For Ethernet cables to be used in the system, select the ones that meet the specifications in the user's
manual for the module used. If not, normal data transmission is not guaranteed.
● Do not apply the 24VDC power before connecting a sensor head. If the power is applied before wiring,
normal data transmission is not guaranteed.