User Manual

LOGO! functions
4.4 Special functions list - SF
LOGO!
178 Manual, 06/2014, A5E33039675
Timing diagram
Functional description
The hours counter monitors input En. When En = 1, LOGO! computes the time expired and
the time-to-go MN. LOGO! shows these times in parameter assignment mode. Output Q is
set when the time-to-go MN = 0.
A signal at reset input R resets output Q and sets the preset value of MI at the counter for
the duration of MN. The hours counter OT is not affected.
With a signal at the reset input Ral, you reset output Q and set the preset value of MI at the
counter for the duration of MN. The hours counter OT is reset to zero.
Depending on your configuration of parameter Q, the output is either reset with a signal at
input R or Ral ("Q→0:R"), or when a reset signal is set hi, or the En signal is set lo
("Q→0:R+En").
Viewing the MI, MN and OT values
● LOGO! Basic: You can open the parameter assignment mode when the system is in RUN
to view the actual values of MI, MN and OT.
● LOGO! Pure: In LOGO!Soft Comfort, you can use the Online Test to read these values.
For further information, see chapter "LOGO! software (Page 283)".
● In LOGO!Soft Comfort you can get the hours counter via the "Tools -> Transfer: Hours
counter" menu command.
Limit value of OT
The value of the operating hours in OT is retained when you reset the hours counter with a
signal at input R. The hours counter OT will be reset to zero with a transition from 0 to 1 at