User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
165
● 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 lighting switch (Page 179) (current time Ta)
● Multiple function switch (Page 182) (current time Ta)
● Stopwatch (0BA7 only) (Page 198) (actual value AQ)
● Threshold trigger (Page 210) (actual value Fre)
Select the re
quire
d function by the block number. The timebase is configurable. For
information on valid timebase ranges and parameter preset, refer to the On-delay
(Page 160) topic.
Timing diagram
5
4
77
7UJ
7KHEROGVHFWLRQRIWKH
WLPLQJGLDJUDPDOVR
DSSHDUVLQWKH
RIIGHOD\V\PERO
7DH[SLUHV
Functional description
Output Q is set to hi immediately when the input Trg changes to hi.
The actual time T
a
in LOGO! is retriggered at the 1 to 0 transition of Trg. The output remains
set. Output Q is reset to 0 with off-delay when T
a
reaches the value configured at T (T
a
=T).
The time T
a
is retriggered with a one-shot at input Trg.
You can set input R (Reset) to reset the time T
a
and the output before T
a
has expired.
If retentivity is not set, output Q and the expired time are reset after a power failure.