LS Industrial Systems SV-iS7 PLC User Manual

Chapter 4 CPU Function
4 - 6
4) Current value update and Contact On/Off of Monostable Timer
In general, its operation is same as off-delay timer. However, the change of input condition is ignored
while the timer is operating (decreasing). When current value reaches preset value the timer output
relay is turned off and current value is cleared. Timer diagram of Monostablel timer is as below.
5) Current value update and Contact On/Off of Retriggerable Timer
The operation of retriggerable timer is same as that of monostable timer. Only difference is that the
retriggerable timer is not ignore the input condition of TRTG instruction while the timer is operating
(decreasing). The current value of retriggerable timer will be set as preset value whenever the input
condition of TRTG instruction is turned on.
Remark
Timing Error
- The Maximum timing error of timers of PLC option card is ‘1 scan time + the time from 0 step to timer instruction’
t0 t1
t2 t3
t4
t0
t1
t2
Timer Input
Condition
Timer Output Relay
Timer Preset Value
(PT)
Timer Current Value
(
ET
)
t0+PT
t0
t2+PT
t2
t4+PT
t4
t4
t2=PT
t0
t2 t3
t1
t2
t3
Timer Input
Condition
Timer Output Relay
Timer Preset Value
(PT)
Timer Current Value
(ET)
t0
t3=PT
t4

LS Industrial Systems SV-iS7 PLC Specifications

General

Brand	LS Industrial Systems
Model	SV-iS7 PLC
Category	Computer Hardware
Language	English