Rockwell Automation DeviceLogix System User Manual - Manual (Page 104)

104 Publication RA-UM003B-EN-P - February 2010
Chapter 4 Navigate the Old Ladder Editor Interface
On Delay Timer
The On Delay Timer delays the output response to an input by a
desired amount of time. When the input is true, the Timer increments
the Accumulator and when the input goes false, the Timer resets the
Accumulator. Each Timebase unit of time, the Timer increments the
Accumulator. When the Accumulator reaches the preset value, the
Timer sets the output to true. The Timer maintains the output true
status as long as the input remains true. When the input changes from
true to false, the Timer resets both the output and the Accumulator. If
the input goes false before the time period specified by the Timebase
and Preset, the output remains false and the Accumulator is cleared,
essentially ignoring the input.
If the Timer senses a true level on the Reset input at any time during
the operation of the Timer, it resets the output to false and clears the
Accumulator. Because the reset line is level sensitive, the timer
remains reset until the Timer detects a false on the Reset input. Also,
because the input is level sensitive, the Timer will again begin to
increment the Accumulator if the reset line goes false while the input
remains true. Refer to the illustration of the timer function for
clarification.