User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
183
If your LOGO! is a LOGO! 0BA7, you can additionally use the actual values of the following
functions:
● Analog filter (0BA7 only) (Page 271) (actual value AQ)
● Average value (0BA7 only) (Page 276) (actual value AQ)
● 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 (Page 172) (current time Ta)
● Asynchronous pulse generator (Page 175) (current time Ta)
● Stairway light switch (Page 179) (current time Ta)
● Multiple func
tion switc
h (current time Ta)
●
Stopwatch (Page 198) (actual value AQ)
● Threshold trigger (Page 210) (actual value Fre)
Select the require
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
7
7/
7/ 7/
7UJ
4
7
7DLVEXV\
Functional description
A 0 to 1 transition at input Trg sets output Q.
If output Q = 0, and input Trg is set hi at least for the duration of T
L
, the permanent lighting
function is enabled and output Q is set accordingly.
The off-delay T is triggered when input Trg returns to 0 before T
L
has expired.
Output Q is reset when T
a
= T.
You can output an off-warning signal prior to the expiration of the off-delay time (T - T
!
) that
resets Q for the duration of the prewarning time period T
!L
. A subsequent signal at Trg
always resets T and the output Q.
If retentivity is not set, output Q and the expired time are reset after a power failure.