Omron CP1L Operation Manual page 29

Application Precautions
• Use the dedicated connecting cables specified in this manual to connect
the Units. Using commercially available RS-232C computer cables may
cause failures in external devices or the CPU Unit.
• The user program and parameter area data in the CPU Unit is backed up
in the built-in flash memory. The BKUP indicator will light on the front of
the CPU Unit when the backup operation is in progress. Do not turn OFF
the power supply to the CPU Unit when the BKUP indicator is lit. The data
will not be backed up if power is turned OFF.
• Do not turn OFF the power supply to the PLC while the Memory Cassette
is being written. Doing so may corrupt the data in the Memory Cassette.
The BKUP indicator will light while the Memory Cassette is being written.
Wait for the BKUP indicator to go out before turning OFF the power sup-
ply to the PLC.
• Before replacing the battery, supply power to the CPU Unit for at least 5
minutes and then complete battery replacement within 5 minutes of turn
OFF the power supply. Memory data may be corrupted if this precaution is
not observed.
• Always use the following size wire when connecting I/O terminals:
AWG22 to AWG18 (0.32 to 0.82 mm
• Dispose of the product and batteries according to local ordinances as
they apply.
Have qualified specialists properly dispose of used batteries as industrial
waste.
• UL standards required that batteries be replaced only by experienced
technicians. Do not allow unqualified persons to replace batteries. Also,
always follow the replacement procedure provided in the manual.
• Never short-circuit the positive and negative terminals of a battery or
charge, disassemble, heat, or incinerate the battery. Do not subject the
battery to strong shocks or deform the barry by applying pressure. Doing
any of these may result in leakage, rupture, heat generation, or ignition of
the battery. Dispose of any battery that has been dropped on the floor or
otherwise subjected to excessive shock. Batteries that have been sub-
jected to shock may leak if they are used.
• Always construct external circuits so that the power to the PLC it turned
ON before the power to the control system is turned ON. If the PLC power
supply is turned ON after the control power supply, temporary errors may
result in control system signals because the output terminals on DC Out-
put 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.
• 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.)
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