User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
152 Manual, 06/2014, A5E33039675
4.4.8
Random generator
Short description
The random generator function sets an output randomly within a configured time.
Symbol in LOGO!
Wiring
Description
Input En A positive edge ( 0 to 1 transition) at input En
(Enable) triggers the on-delay time of the random
generator.
A negative edge ( 1 to 0 transition) at input En
(Enable) triggers the off-delay time of the random
generator.
Parameter LOGO! sets the on-delay at random to a value
between 0 s and T
H
.
The off-delay is set at random to a value between 0 s
and T
L
.
Output Q LOGO! sets output Q when the on-delay expires and
if En is still set. LOGO! resets Q when the off-delay
expires, provided LOGO! has not set En again
meanwhile.
Parameter T
H
and T
L
Note the defaults of the T
H
and T
L
parameters listed in topic Time response (Page 128).
The actual value of another already-programmed function can provide the on-delay time TH
and the off-delay time TL. 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)
● Retentive on-delay (Page 144) (current time Ta)