As a rule, when placing switches, do not overlay one switch on another.
When switches are overlaid, the switch placed first is valid.
Other switches which are placed secondly and later are invalid.

	However, if two switches must be unavoidably overlaid, it is possible to specify which switch is to be valid, depending on whether the switch is placed first or on top.
	Setting location: Select [System Setting] → [Unit Setting] → [General Settings] and check or uncheck [If a switch is overlaid on another, enable the upper switch].