User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 06/2014, A5E33039675
145
● Edge-triggered wiping relay (Page 148)(current time Ta)
● Asynchronous pulse generator (Page 150)(current time Ta)
● Stairway lighting switch (Page 154)(current time Ta)
● Multiple function switch (Page 156)(current time Ta)
● Stopwatch (Page 171)(actual value AQ)
● Threshold trigger (Page 180) (actual value Fre)
Select the required function by the block number. The timebase is configurable. For
information on valid ranges and parameter defaults, refer to Section "On-delay (Page 136)".
Timing diagram
Functional description
The 0 to 1 signal transition at input Trg triggers the current time T
a
. LOGO! sets output Q
when T
a
= T. A further signal at input Trg does not influence the time T
a
.
LOGO! resets the output and the time T
a
with the next 1 signal at input R.
If the block is retentive, LOGO! resets output Q and the expired time to the values before a
power failure; if the block is not retentive, LOGO! resets output Q and the expired time to
defaults after a power failure.