Mitsubishi MELSEC Q series User Manual page 5

● When changing data from a peripheral device connected to the CPU module during operation,
configure an interlock circuit in the program to ensure that the entire system will always operate safely.
For other controls to a running programmable controller (such as program modification or operating
status change), read relevant manuals carefully and ensure the safety before the 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 program, and determine
corrective actions to be taken between the external device and CPU module in case of a
communication failure.
● An absolute position restoration by the positioning function may turn off the servo-on signal (servo off)
for approximately 20ms, and the motor may run unexpectedly. If this causes a problem, provide an
electromagnetic brake to lock the motor during absolute position restoration.
[Design Precautions]
● Do not install the control lines or communication cables together with the main circuit lines or power
cables. Keep a distance of 100mm or more between them. Failure to do so may result in malfunction
due to noise.
● During control of an inductive load such as a lamp, heater, or solenoid valve, a large current
(approximately ten times greater than normal) may flow when the output is turned from off to on.
Therefore, use a module that has a sufficient current rating.
● After the CPU module is powered on or is reset, the time taken to enter the RUN status varies
depending on the system configuration, parameter settings, and/or program size. Design circuits so
that the entire system will always operate safely, regardless of the time.
WARNING
CAUTION
3