Omron CQM1H series Operation Manual page 19

Application Precautions
• Check that the DIP switches and data memory (DM) are properly set before
starting operation.
• Check the user program for proper execution before actually running it on the
Unit. Not checking the program may result in an unexpected operation.
• Resume operation only after transferring to the new CPU Unit the contents of
the DM and HR Areas required for resuming operation. Not doing so may result
in an unexpected operation.
• Confirm that no adverse effect will occur in the system before attempting any of
the following. Not doing so may result in an unexpected operation.
• Changing the operating mode of the PC.
• Force-setting/force-resetting any bit in memory.
• Changing the present value of any word or any set value in memory.
• Do not pull on the cables or bend the cables beyond their natural limit. Doing
either of these may break the cables.
• Do not place objects on top of the cables. Doing so may break the cables.
• When replacing parts, be sure to confirm that the rating of a new part is correct.
Not doing so may result in malfunction or burning.
• Before touching the Unit, be sure to first touch a grounded metallic object in
order to discharge any static built-up. Not doing so may result in malfunction or
damage.
• Do not turn OFF the power supply to the Unit while data is being transferred.
• When transporting or storing the product, cover the PCBs with electrically con-
ductive materials to prevent LSIs and ICs from being damaged by static elec-
tricity, and also keep the product within the specified storage temperature
range.
• Install the Unit properly as specified in the operation manual. Improper installa-
tion of the Unit may result in malfunction.
• Provide a control circuit so that the power to the I/O circuits will turn ON after
the power to the PC turns ON. If the power to the I/O circuits turns ON before
the power to the PC turns ON, the system may malfunction temporarily.
• If the I/O Hold Bit (SR 25212) is turned ON, the outputs from the PC will not be
turned OFF and will maintain their previous status when the PC is switched
from RUN or MONITOR mode to PROGRAM mode. Make sure that the exter-
nal loads will not produce dangerous conditions when this occurs. (When op-
eration stops for a fatal error, including those produced with the FALS(07)
instruction, all outputs from Output Unit will be turned OFF and only the internal
output status will be maintained.)
• When assembling the Units or mounting the end cover, be sure to lock them
securely as shown in the following illustrations. If they are not properly locked,
desired functionality may not be achieved.
• Be sure to mount the end cover to the rightmost Unit.
• Be sure that the connectors, terminal blocks, connection cables, and other
items with locking devices are properly locked into place. Improper locking
may result in malfunction.
• Be sure to confirm the orientation and polarities when connecting terminal
blocks and connectors.
• Do not touch the back side of circuit boards or the components mounted to
them with your bare hands. There are sharp leads and other parts on the
boards that may cause injury if handled improperly.
• Provide sufficient clearances around the Unit and other devices to ensure
proper heat dissipation. Do not cover the ventilation openings of the Unit.
• Do not allow metallic objects or conductive wires to enter the Unit.
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