The Common Control Circuit; Example 4: Condition Control; Example 5, 6: Interlock/Sequential Control; Example 7: Oscillating Circuit - Delta C2000 series User Manual

The common control circuit

Example 4: condition control

X1 and X3 can start/stop Y1 separately, X2 and X4 can start/stop Y2 separately and they are all self
latched circuit. Y1 is an element for Y2 to do AND function due to the normally open contact
connects to Y2 in series. Therefore, Y1 is the input of Y2 and Y2 is also the input of Y1.
X1
X3
Y1
X2
X4
Y2
Example 5: Interlock control
The figure above is the circuit of interlock control. Y1 and Y2 will act according to the start
contact X1 and X2. Y1 and Y2 will act not at the same time, once one of them acts and the other
won't act. (This is called interlock.) Even if X1 and X2 are valid at the same time, Y1 and Y2
won't act at the same time due to up-to-down scan of ladder diagram. For this ladder diagram,
Y1 has higher priority than Y2.
X1
X3 Y2
Y1
X2
Y1
X4
Y2
Example 6: Sequential Control
X1
X3
Y1
X2
X4
Y2

Example 7: Oscillating Circuit

The period of oscillating circuit is ΔT+ΔT
Y1
Y1
Y1
Y2
Y1
Y2
Y2
Y1
Y1
Y2
Y1
Chapter 16 PLC Function C2000 Series
X1
X3
X2
X4
Y1
Y2
X1
X3
X2
X4
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.
Y1
T T
16-16