User's Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
179
4.4.9 Stairway lighting switch
Short description
An input edge triggers a configurable and retriggerable time. The output is reset after this
time has expired. A warning signal can be output before this time has expired to warn of the
impending shutdown.
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.
4
7UJ
3DU
Output Q Q is reset after the time T has expired. A warning
signal can be output before this time has expired.
Parameter T, T
!
and T
!L
Note the defaults of the T parameters listed in topic Time response (Page 151).
The off-delay time T, the pre-warning time T
!
and the pre-warning period T
!L
can be provided
by the actual value of another already-programmed function. You can use the actual values
of the following functions:
●
Analog comparator (Page 218) (actual value Ax – Ay)
●
Analog threshold trigger (Page 213) (actual value Ax)
●
Analog amplifier (Page 226) (actual value Ax)
●
Analog multiplexer (Page 248) (actual value AQ)
●
Analog ramp (Page 251) (actual value AQ)
●
Mathematic instruction (Page 265) (actual value AQ)
●
PI controller (Page 256) (actual value AQ)
●
Up/down counter (Page 201) (actual value Cnt)
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)