Set instruction S (set): set the specified bit address (change to 1 state and keep it), refer to the following program,
It can be understood that when the normally open contact of M0.1 is turned on, Q4.3 becomes 1 state and maintains this state, even if the normally open contact of M0.1 is disconnected, it still maintains 1 state
Reset instruction R (Reset): reset the specified address bit (change to 0 state and keep it), refer to the following program
This program can be understood in this way, when the normally open contact of M0.3 is closed, Q4.3 becomes 0 state and maintains this state, even if the normally open contact of M0.3 is disconnected, it still maintains 0 state