User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
142 Manual, 06/2014, A5E33039675
4.4.3
On-/off-delay
Short description
The on-/off-delay function sets the output after the set on-delay time has expired, and resets
it upon expiration of the off-delay time.
Symbol in LOGO!
Wiring
Description
Input Trg A positive edge (0 to 1 transition) at input Trg
(Trigger) triggers the on-delay time T
H
.
A negative edge (1 to 0 transition) at input Trg
(Trigger) triggers the off-delay time T
L
.
Parameter T
H
is the time after which the output is set hi (output
signal transition 0 to 1).
T
L
is the time after which the output is reset ( output
signal transition 1 to 0).
Retentivity:
/ = No retentivity
R = The status is retentive.
Output Q LOGO! sets Q when the configured time T
H
expires
and Trg is still set. LOGO! resets Q when T
L
expires,
if the trigger Trg has not been set.
Parameters T
H
and T
L
Note the preset values for the parameters T
H
and T
L
in topic Time response (Page 128).
The actual value of another, already-configured function can provide the on-delay and off-
delay times for parameters T
H
and T
L
. You can use the actual values of the following
functions:
● Analog comparator (Page 188)(actual value Ax - Ay)
● Analog threshold trigger (Page 183)(actual value Ax)
● Analog amplifier (Page 195)(actual value Ax)
● Analog multiplexer (Page 213)(actual value AQ)
● Analog ramp (Page 216)(actual value AQ)
● Mathematic instruction (Page 227) (actual value AQ)
● PI controller (Page 220)(actual value AQ)
● Up/down counter (Page 173)(actual value Cnt)
● Analog filter (Page 232) (actual value AQ)
● Average value (Page 237) (actual value AQ)
● Max/Min (Page 234) (actual value AQ)
● On-delay (Page 136)(current time Ta)
● Off-delay (Page 140)(current time Ta)