User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 06/2014, A5E33039675
209
4.4.26
Softkey
Short description
This special function has the effect of a mechanical pushbutton or switch.
Symbol in LOGO!
Wiring
Description
Input En Output Q is set with a 0 to 1 transition of the signal at
input En (Enable), and if "Switch=On" was confirmed
in parameter assignment mode.
Parameter Programming mode:
Selecting the function for pushbutton action for the
duration of one cycle, or for switching action.
Start: on or off state, initialized at the first start of the
program if retentivity is disabled.
Retentivity:
/ = no retentivity
R = the status is retentive.
Parameter assignment mode (RUN mode):
Switch: switches the momentary pushbutton (switch)
on or off.
Output Q Switches on if En=1 and Switch=On was confirmed
with
OK
.
Factory setting
The default parameter setting is switching action.
Timing diagram
Functional description
In parameter assignment mode, the output is set with a signal at input En, if the "Switch"
parameter is set to "On" and confirmed with
OK
. Whether the function was configured for
pushbutton or switching action is of no concern here.
The output is reset to "0" in the following three cases:
● After a 1 to 0 transition at input En
● When the function was configured for momentary pushbutton action, and one cycle has
expired since it was switched on
● When the position "Off" was selected at the "Switch" parameter and confirmed with
OK
in
parameter assignment mode