Mitsubishi Electric MELCEC Q Series User Manual page 148

9. LOADING AND INSTALLATION
WARNING
CAUTION
For the operating status of each station after a communication failure, refer to
relevant manuals for the network.
Incorrect output or malfunction due to a communication failure may result in an
accident.
When controlling a running programmable controller from a peripheral connected to
the CPU module or from a personal computer connected to a special function
module, configure an interlock circuit in the sequence program to ensure that the
entire system will always operate safely.
For program modification and operating status change, read relevant manuals
carefully and ensure the safety before operation.
Especially, in the case of a control from an external device to a remote
programmable controller, immediate action cannot be taken for a problem on the
programmable controller due to a communication failure.
To prevent this, configure an interlock circuit in the sequence program, and
determine corrective actions to be taken between the external device and CPU
module in case of a communication failure.
When setting up the system, do not allow any empty slot on the base unit.
If any slot is left empty, be sure to use a blank cover (A1SG60) or a dummy module
(A1SG62) for it.
Otherwise, internal parts of the module may be flied in the short circuit test or when
an overcurrent or overvoltage is accidentally applied to the external I/O section.
Do not install the control lines or communication cables together with the main
circuit or power cables.
Keep a distance of 100mm or more between them.
Failure to do so may result in malfunction due to noise.
When a device such as a lamp, heater, or solenoid valve is controlled through
an output module, a large current (approximately ten times greater than normal)
may flow when the output is turned from off to on.
Take measures such as replacing the module with one having a sufficient current
rating.
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