Siemens LOGO! Series Manual page 180

LOGO! functions
4.4 Special functions list - SF
● Off-delay (Page 164) (current time Ta)
● On-/off-delay (Page 166) (current time Ta)
● Retentive on-delay (Page 168) (current time Ta)
● Wiping relay(pulse output) (Page 170) (current time Ta)
● Edge triggered wiping relay (Page 172) (current time Ta)
● Asynchronous pulse generator (Page 175) (current time Ta)
● Stairway lightswitch (current time Ta)
● Multiple function switch (Page 182) (current time Ta)
● Stopwatch (Page 198) (actual value AQ)
● Threshold trigger (Page 210) (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 the On-delay (Page 160) topic.
Timing diagram
Functional description
A 0 to 1 signal transition at input Trg sets output Q. The next 1 to 0 transition at Trg
retriggers the current time T
Output Q is reset when T
T ) has expired to reset Q for the time of the pre-warning period T
!
A further one-shot at input Trg during T
If retentivity is not set, output Q and the expired time are reset after a power failure.
180
, and output Q remains set.
a
= T. You can output a warning signal before the off-delay time (T -
a
retriggers the time T
a
.
!L
.
a
Manual, 04/2011, A5E03556174-01
LOGO!