User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
154 Manual, 06/2014, A5E33039675
4.4.9
Stairway lighting switch
Short description
An input edge triggers a configurable and retriggerable time. LOGO! resets the output after
this time expires. LOGO! can optionally output a warning signal to warn of the impending
time expiration.
Symbol in LOGO!
Wiring
Description
Input Trg A signal at input Trg (Trigger) triggers the off-delay
time for the stairway lighting switch.
Parameter T represents the off-delay time of the output (output
signal transition 1 to 0).
T
!
determines the triggering time for the pre-warning.
T
!L
determines the length of the pre-warning signal.
Retentivity:
/ = No retentivity
R = The status is retentive.
Output Q LOGO! resets Q after the time T expires. LOGO!
outputs a warning signal before this time expires.
Parameter T, T
!
and T
!L
Note the defaults of the T parameters listed in topic Time response (Page 128).
The actual value of another already-programmed function can provide the off-delay time T,
the pre-warning time T
!
and the pre-warning period 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)
● On-/off-delay (Page 142) (current time Ta)