Siemens LOGO! Series Manual page 178

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 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 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
The 0 to 1 transition at input En triggers a random on-delay time between 0 s and T
output is set when the on-delay time has expired and if the signal at input En remains hi at
least for the duration of this time.
The time is reset if input En is reset before the on-delay time has expired.
A 1 to 0 transition at input EN triggers a random off-delay time between 0 s and T
The output is reset after the off-delay time has expired, provided input En remains lo at least
for the duration of this time.
The time is reset if the signal at input En changes to 1 again before the off-delay time has
expired.
The time expired is reset after a power failure.
178
. The
H
.
L
Manual, 04/2011, A5E03556174-01
LOGO!