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5Application Precautionsxiv•Mounting or dismounting the CPU board or expansion I/O board.
•Setting switches or rotary switches.
•Connecting or wiring the cables.
•Connecting or disconnecting the connectors.
Caution Failure to abide by the following precautions could lead to faulty operation of the
PC or the system, or could damage the PC. Always heed these precautions.
•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.
•Construct a control circuit so that power supply for the I/O circuits does not
come ON before power supply for the PC. If power supply for the I/O circuits
comes ON before power supply for the PC, normal operation may be tempo-
rarily interrupted.
•If the operating mode is changed from RUN or MONITOR mode to PROGRAM
mode, with the IOM Hold Bit ON, the output will hold the most recent status. In
such a case, ensure that the external load does not exceed specifications. (If
operation is stopped because of an operation error (including FALS instruc-
tions), the values in the internal memory of the CPU board will be saved, but
the outputs will all turn OFF.)
•Always use the power supply voltage specified in the operation manuals. An
incorrect voltage may result in malfunction or burning.
•Take appropriate measures to ensure that the specified power with the rated
voltage 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-circuit-
ing in external wiring. Insufficient safety measures against short-circuiting may
result in burning.
•Do not apply voltages to the input terminals in excess of the rated input voltage.
Excess voltages may result in burning.
•Do not apply voltages or connect loads to the output terminals in excess of the
maximum switching capacity. Excess voltage or loads may result in burning.
•Be sure that all the mounting screws, terminal screws, and cable connector
screws are tightened to the torque specified in the relevant manuals. Incorrect
tightening torque may result in malfunction.
•When wiring the CPM2B, take countermeasures to prevent wiring cuttings
from coming into contact with the product, such as covering the whole product
with a dustproof cover. If wiring cuttings adhere to the PCB or circuit elements
they may cause short-circuiting.
•Be sure to perform wiring in accordance with the relevant operation manual.
Incorrect wiring may result in burning.
•Double-check all the wiring before turning ON the power supply. Incorrect wir-
ing may result in burning.
•Be sure that the terminal blocks, expansion cables, and other items with lock-
ing devices are properly locked into place. Improper locking may result in mal-
function.
•Be sure that terminal blocks and connectors are connected in the specified di-
rection with the correct polarity. Not doing so may result in malfunction.
•Check the user program for proper execution before actually running it on the
PC. Not checking the program 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.