Chapter 4 CPU Function
4 - 5
1) Current value update and Contact On/Off of On Delay Timer
The current value of timer is updated when the input condition of TON instruction turns On. When the
current value reaches the preset value (current value = preset value), the timer output relay (Txxx)
turns On.
2) Current value update and Contact On/Off of Off Delay Timer
The timer output relay (Txxx) is turned On when the input condition of TOFF is turned On. When the
input condition is turned off, the current value starts to decrease. The timer output relay (Txxx) is
turned Off when the elapsed time reaches to preset time (current value = preset value). Timer
diagram of Off Delay Timer is as below
.
3) Current value update and Contact On/Off of Integral Timer
The current value will be increased when input condition is turned On. Timer output relay is turned
On when the current value reaches to timer preset value. Timer output relay turned On keeps the
status before reset input is turned On. Timer diagram of Integral timer is as below.
t0+PT
t0
t1 t2
t3
t4
t5
t5
t1
t4+PT
t0 t1
t2 t3
t4
t5
Timer Output Relay
Timer Preset Value
(PT)
Timer Current Value
(ET)
t1+PT
t0
t1
t2 t3 t4
t5
t5+PT
t0
t1
t2
t3
t5
Timer Input
Condition
Timer Output Relay
Timer Preset Value (PT)
Timer Current Value (ET)
t0 t1 t2
t4
t1
Timer Input
Condition
Timer Output Relay
Timer Preset Value (PT)
Timer Current Value (ET)
t0
t2
t4+PT
t4
Timer Reset Input
t3
PT=t1-t0+t3-t2
