When connecting a peripheral device to the CPU module or connecting a
personal computer or the like to the intelligent function module to
exercise control (data change) on the running PLC, configure up an
interlock circuit in the sequence program to ensure that the whole
system will always operate safely.
Also before exercising other control (program change, operating status
change (status control)) on the running PLC, read the manual carefully
and fully confirm safety.
Especially for the above control on the remote PLC from an external
device, an immediate action may not be taken for PLC trouble due to a
data communication fault.
In addition to configuring up the interlock circuit in the sequence program,
corrective and other actions to be taken as a system for the occurrence of
a data communication fault should be predetermined between the external
device and PLC CPU.
When configuring a system, do not leave any slots vacant on the base.
Should there be any vacant slots, always use a blank cover (A1SG60) or
dummy module (A1SG62).
When the extension base A1S52B, A1S55B or A1S58B is used, attach the
dustproof cover supplied with the product to the module installed in slot
If the cover is not attached, the module's internal parts may be
dispersed when a short-circuit test is performed or
overcurrent/overvoltage is accidentally applied to the external I/O area.
Do not bunch the control wires or communication cables with the main
circuit or power wires, or install them close to each other. They should
be installed 100 mm (3.94 inch) or more from each other. Not doing so
could result in noise that would cause erroneous operation.
When controlling items like lamp load, heater or solenoid valve using an
output module, large current (approximately ten times greater than that
present in normal circumstances) may flow when the output is turned
OFF to ON.
Take measures such as replacing the module with one having sufficient