Delta DVP-ES2/EX2/SS2/SA2/SX2/SE manual Example 9 Oscillating Circuit with Timer

1. PLC Concepts

Example 9 – Oscillating Circuit with Timer

An oscillating circuit with cycle nT+ΔT

X0 Y1

TMR T0 Kn X0

T0

Y1

Y1

nT T

When X0 = ON, T0 starts timing (nT). Once the set time is reached, contact T0 = ON to enable Y1(ΔT). In next scan, Timer T0 is reset due to the reversed status of contact Y1. Therefore contact

T0 is reset and Y1 = OFF. In next scan, T0 starts timing again. The process forms an oscillating circuit with output cycle nT+ΔT.

Example 10 - Flashing Circuit

The ladder diagram uses two timers to form an oscillating circuit which enables a flashing indicator or a buzzing alarm. n1 and n2 refer to the set values in T1 and T2 and T refers to timer resolution.

X0	T2
		TMR	T1	Kn1	X0
T1		TMR	T2	Kn2			n2 T
X0	T1				Y1
		Y1
						n1 T

Example 11 - Trigger Circuit

In this diagram, rising-edge contact X0 generates trigger pulses to control two actions executing interchangeably.

X0

M0 Y1

M0 Y1

M0 X0

Y1

M0

Y1

T

Example 12 - Delay OFF Circuit

If X0 = ON, timer T10 is not energized but coil Y1 is ON. When X0 is OFF, T10 is activated. After 100 seconds (K1000 × 0.1 sec = 100 sec), NC contact T10 is ON to turn off Y1. Turn-off action is delayed for 100 seconds by this delay OFF circuit.

X0 TMR T10 K1000 X0

T10

Y1 Y1

Timer Resolution: 0.1 sec

100 seconds

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