Siemens LOGO! Series Manual page 208

LOGO! functions
4.4 Special functions list - SF
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
Ral. The hours counter OT continues the count as long as En = 1, irrespective of the status
at the reset input R. The counter limit of OT is 99999 h. The hours counter stops when it
reaches this value.
In programming mode, you can set the initial value of OT. MN is calculated according to the
following formula when reset input R is never enabled: MN = MI - (OT % MI). The % operator
provides an integer division remainder.
Example:
MI = 30h, OT = 100h
MN = 30 - (100 % 30)
MN = 30 -10
MN = 20h
MN
OT
In runtime mode, the value OT can not be preset. If the value for MI is changed, there would
be no calculation for the MN. MN would take on the value of MI.
Setting the Par parameter
View in programming mode:
MI is the configurable time interval. The permissible range of values is 0 to 9999 hours.
208
0 20 40 60 80
30h 30h 30h
100h
100 120
30h
20h
MI
Manual, 04/2011, A5E03556174-01
LOGO!