Mitsubishi MELSEC System Q Manual page 109

An Introduction to Programming
NOTE Very important is the order of the instructions, especially the reset of the variables
OPEN_GATE and CLOSE_GATE by the safety facilities at the end of the program after the
setting of these variables.
Because of the execution of the program from top to bottom (see chapter 2.2), reset has a
higher priority than set and therefore safety is ensured.
MELSEC System Q Beginners Manual
Programming PLC Applications
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