D-24
Example 6: Sequential Control
X3
Y1
X1
Y1
X4
Y2
X2
Y2
Y1
Y2
If add normally close contact Y2 into Y1
circuit to be an input for Y1 to do AND
function. (as shown in the left side) Y1 is an
input of Y2 and Y2 can stop Y1 after acting.
In this way, Y1 and Y2 can execute in
sequential.
Example 7: Oscillating Circuit
The period of oscillating circuit is
Δ
T+
Δ
T
Y1
Y1
Y1
T
T
The figure above is a very simple ladder step diagram. When starting to scan Y1 normally
close contact, Y1 normally close contact is close due to the coil Y1 is OFF. Then it will scan
Y1 and the coil Y1 will be ON and output 1. In the next scan period to scan normally close
contact Y1, Y1 normally close contact will be open due to Y1 is ON. Finally, coil Y1 will be
OFF. The result of repeated scan, coil Y will output the vibrating pulse with cycle time
Δ
T(On)+
Δ
T(Off).
The vibrating circuitry of cycle time
Δ
T(On)+
Δ
T(Off):
T0
X0
TMR
Y1
Y1
T0
Kn
Y1
T
T
n
X0
The figure above uses timer T0 to control coil Y1 to be ON. After Y1 is ON, timer T0 will be
closed at the next scan period and output Y1. The oscillating circuit will be shown as above. (n
is the setting of timer and it is decimal number. T is the base of timer. (clock period))
