User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
148 Manual, 06/2014, A5E33039675
4.4.6
Edge-triggered wiping relay
Short description
An input pulse generates a preset number of output pulses with a defined pulse/pause ratio
(retriggerable), after a configured delay time has expired.
Symbol in LOGO!
Wiring
Description
Input Trg A signal at input Trg (Trigger) triggers the times for
the edge triggered wiping relay.
Input R A signal at input R resets the current time (T
a
) and the
output.
Parameter The interpulse width T
L
and the pulse width T
H
are
configurable.
N determines the number of pulse/pause cycles
TL/TH:
Range of values: 1...9
Retentivity:
/ = No retentivity
R = The status is retentive.
Output Q
Q is set after TL expires, and reset after TH expires.
Parameters TH and TL
Note the information on parameter T in topic Time response (Page 128).
The actual value of another already-programmed function can provide the pulse width TH
and the interpulse width 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)