Omron SYSMAC CS Series Operation Manual page 33

Application Precautions
output terminals on DC Output Units and other Units will momentarily turn
ON when power is turned ON to the PLC.
• Fail-safe measures must be taken by the customer to ensure safety in the
event that outputs from Output Units remain ON as a result of internal cir-
cuit failures, which can occur in relays, transistors, and other elements.
• Fail-safe measures must be taken by the customer to ensure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal
lines, momentary power interruptions, or other causes.
• Interlock circuits, limit circuits, and similar safety measures in external cir-
cuits (i.e., not in the Programmable Controller) must be provided by the
customer.
• Do not turn OFF the power supply to the PLC when data is being trans-
ferred. In particular, do not turn OFF the power supply when reading or
writing a Memory Card. Also, do not remove the Memory Card when the
BUSY indicator is lit. To remove a Memory Card, first press the memory
card power supply switch and then wait for the BUSY indicator to go out
before removing the Memory Card.
• If the I/O Hold Bit is turned ON, the outputs from the PLC will not be
turned OFF and will maintain their previous status when the PLC is
switched from RUN or MONITOR mode to PROGRAM mode. Make sure
that the external loads will not produce dangerous conditions when this
occurs. (When operation stops for a fatal error, including those produced
with the FALS(007) instruction, all outputs from Output Unit will be turned
OFF and only the internal output status will be maintained.)
• The contents of the DM, EM, and HR Areas in the CPU Unit are backed
up by a Battery. If the Battery voltage drops, this data may be lost. Provide
countermeasures in the program using the Battery Error Flag (A40204) to
re-initialize data or take other actions if the Battery voltage drops.
• When supplying power at 200 to 240 V AC, always remove the metal
jumper from the voltage selector terminals on the Power Supply Unit
(except for Power Supply Units with wide-range specifications). The prod-
uct will be destroyed and must be replaced if 200 to 240 V AC is supplied
while the metal jumper is attached. Refer to 5-3 Wiring for details.
• Always use the power supply voltages specified in the operation manuals.
An incorrect voltage may result in malfunction or burning.
• Do not apply a force greater than 100 N on the terminal block when tight-
ening the terminals.
• Take appropriate measures to ensure that the specified power with the
rated voltage and frequency is supplied. Be particularly careful in places
where the power supply is unstable. An incorrect power supply may result
in malfunction.
• Install external breakers and take other safety measures against short-cir-
cuiting in external wiring. Insufficient safety measures against short-cir-
cuiting may result in burning.
• Install Units as far as possible away from devices that generate strong,
high-frequency noise.
• Do not apply voltages to the Input Units in excess of the rated input volt-
age. Excess voltages may result in burning.
• Do not apply voltages or connect loads to the Output Units in excess of
the maximum switching capacity. Excess voltage or loads may result in
burning.
5
xxxiii