User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
Manual, 04/2011, A5E03556174-01
243
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.
4
(Q
3DU
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
4
(Q
6ZLWFK
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
If retentivity is not set, output Q is initialized after a power failure according to your
configuration at the "Start" parameter.