PLC Ladder Diagram Example#5 : Conditional control
X1 and X3 enables and disables Y1; X2 and X4 enables and disables Y2, and all are latched.
Due to that the normally open contact of Y1 is connected to the circuit of Y2 in series, Y1 becomes an AND condition for Y2.Therefore, only when Y1 is enabled can Y2 be enabled.
PLC Ladder Diagram Example#4 : Power shutdown
The auxiliary relay M512 is latched. The circuit can not only be latched when the power is on, but also keep the continuity ofthe original control when the power is shut down and switchedon again.
Start first latched PLC ladder Example#2
PLC Ladder Programming Example#2 Today is Start first latched
When the normally open contact X1 = On and the normally closed contact X2 = Off,
Y1 will be On and latched.
If you make X2 = On at this time, Y1 will continue to be Onbecause of the latched contact.
It is the reason why this iscalled “start first”.
