Omron CQM1 Operation Manual page 18

Application Precautions
• 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.
• Be sure that the terminal blocks, Memory Units, expansion cables, and
other items with locking devices are properly locked into place. Improper
locking may result in malfunction.
• Disconnect the functional ground terminal when performing withstand
voltage tests. Not disconnecting the functional ground terminal may result
in burning.
• Double-check all the wiring and switch settings before turning ON the
power supply. Incorrect wiring or switch settings may result in burning.
• 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 opera-
tion.
• Resume operation only after transferring to the new CPU Unit the con-
tents 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 mal-
function or damage.
• Do not turn OFF the power supply to the Unit while data is being trans-
ferred.
• When transporting or storing the product, cover the PCBs with electrically
conductive materials to prevent LSIs and ICs from being damaged by
static electricity, and also keep the product within the specified storage
temperature range.
• Install the Unit properly as specified in the operation manual. Improper
installation 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 external loads will not produce dangerous conditions when this
occurs. (When operation stops for a fatal error, including those produced
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