xxiv
Application Precautions 5
• Always turn OFF the power supply to th e CP U Unit, S laves, and Commu-
nications Units before attempting any of the following. Not turning OFF
the power supply may result in malfunction or electric shock.
• Mounti ng or dismounting I/O Units, CPU Units, Memory Packs, or
Master Units.
• Assembling the Units.
• Setting DIP switches o r rotary switches.
• Connecting c ables or wiring the system.
!Caution Failure to abide by the following precautions could lead to faulty operation of
the Ethernet Unit or the system, or could damage the Ether net Unit. Always
heed these precautions.
• Fail-safe measures must be taken by the customer to ens ure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal
lines, momentary power interruptions, or other causes.
• Interlo ck circuits, limit circuits, and similar safety measures in external c ir-
cuits (i.e., not in the Programmable Controller) must be provided by th e
customer.
• Always use the power su pply voltages specified in the operation manuals.
An incorrect voltage may result in malfunction or burning.
• Take appropriate measures to ensure that the s pecified power with the
rated voltage and frequency is supplied. Be particula rly careful i n places
where the power supply is unstable. An incorrect power supply may result
in malfunction.
• Install exter nal breakers and take other safety measures against short-cir -
cuiting in external wiring. Insufficient safety measures agai nst short-cir-
cuiting may result in burning.
• Do not install the Uni t near devices that generate strong high-frequency
noise.
• Do not drop the Unit or subject it to excessive vibration or shock.
• Make sure that all the Backplane mounting screws, terminal block screws,
and cable connector screws are tightened to the torque specified in the
relevant manuals. Incorrect tightening torque may result in malfunction.
• Leave the label attached to the Unit whe n wiring. Removing the label may
result in malfunction if foreign matter enters the Unit.
• Remove the label after the completion of wiring to ensure proper heat dis-
sipation. Leaving the label attached may result in malfunction.
• Use crimp terminal s for wiring. Do not connect bare stranded wires
directly to terminals. Connection of bare stranded wires may result in
burning.
• Double-check all wir ing and switch setting s before turning O N the power
supply. Incorrect wiring may result in burning.
• Wire all co nnections correctly.
• Mount Unit s only after checking terminal blocks and connectors com-
pletely.
• Make sure that the terminal blocks, expansion cables, and other items
with locking devices are locked in place.
• When transpo rting the Unit, use special packing boxes and protect it from
being exposed to excessive vibration or impacts during transportatio n.