xix
Safety Precautions
3
!WARNING
Do not touch any of the terminals or terminal blocks while the power is being
supplied. Doing so may result in electric shock.
!WARNING
Provide safety measures in external circuits (i.e., not in the Programmable
Controller), including the following items, in order to ensure safety in the sys-
tem if an abnormality occurs due to malfunction of the PC or another external
factor affecting the PC operation. Not doing so may result in serious acci-
dents.
• Emergency stop circuits, interlock circuits, limit circuits, and similar safety
measures must be provided in external control circuits.
• The PC will turn OFF all outputs when its self-diagnosis function detects
any error or when a severe failure alarm (FALS) instruction is executed.
As a countermeasure for such errors, external safety measures must be
provided to ensure safety in the system.
• The PC outputs may remain ON or OFF due to deposition or burning of
the output relays or destruction of the output transistors. As a counter-
measure for such problems, external safety measures must be provided
to ensure safety in the system.
• When the 24-VDC output (service power supply to the PC) is overloaded
or short-circuited, the voltage may drop and result in the outputs being
turned OFF. As a countermeasure for such problems, external safety
measures must be provided to ensure safety in the system.
!WARNING
Do not attempt to disassemble, repair, or modify any Units. Any attempt to do
so may result in malfunction, fire, or electric shock.
!WARNING
Do not touch the Power Supply Unit while power is being supplied or immedi-
ately after power has been turned OFF. Doing so may result in burns.
!Caution
Execute online edit only after confirming that no adverse effects will be
caused by extending the cycle time. Otherwise, the input signals may not be
readable.
!Caution
Confirm safety at the destination node before transferring a program to
another node or changing contents of the I/O memory area. Doing either of
these without confirming safety may result in injury.
!Caution
Tighten the screws on the terminal block of the AC Power Supply Unit to the
torque specified in the operation manual. The loose screws may result in
burning or malfunction.
