User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
173
● Max/Min (0BA7 only) (Page 273) (actual value AQ)
● On-delay (Page 160) (current time Ta)
● 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 (c
u
rrent time Ta)
●
Asynchronous pulse generator (Page 175) (current time Ta)
● Stairway light switch (Page 179) (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 re
quire
d 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 A
7+7+
4
7UJ
7/ 
1 
7KHEROGVHFWLRQRIWKHWLPLQJ
GLDJUDPDOVRDSSHDUVLQWKH
V\PERORIWKHHGJHWULJJHUHG
ZLSLQJUHOD\
7DLVUXQQLQJ
Timing diagram B
4
1 
7UJ
7/ 7+7/ 7+
7LPLQJGLDJUDPIRUWKHVDPSOH
FRQILJXUDWLRQ
Functional description
A 0 to 1 transition at input Trg triggers the time T
L
(Time Low). After the time T
L
has expired,
output Q is set for the duration of T
H
(Time High).
If there is a further 0 to 1 transition (retriggering pulse) at input Trg before the preset time (T
L
+ T
H
) has expired, T
a
is reset and the pulse/pause cycle is restarted.
If retentivity is not set, output Q and the time are reset after a power failure.