Memory toggle has two inputs (Source, Reset) and one output. The defining characteristics of a memory toggle is that it "remembers" that Source was active until Reset is active, then it reverts to standby again. It's best to illustrate it on an example. You want to fill a tank with water only if it is empty and stop if its full. Here, bottom sensor is false, top sensor is false, and so - the output will be false. If the bottom sensor (SOURCE) sends an active signal (there is