Rockwell Automation DeviceLogix System User Manual - Manual (Page 102)

102 Publication RA-UM003B-EN-P - February 2010
Chapter 4 Navigate the Old Ladder Editor Interface
Timer Element
Pulse Timer
The Pulse Timer generates a true value on its output for a fixed
amount of time. The duration of the true pulse is determined by the
Preset value along with the Timebase of the timer. When the input to
the Timer changes from false to true, it sets the output to true and the
Accumulator starts counting. The Timer then increments the
Accumulator each time the Timebase number of milliseconds has
expired. When the Accumulator reaches the preset value, the Timer
resets the output to false.
In the Pulse Timer, the input acts only as a trigger to start the
Accumulator counting. Once the Accumulator starts timing, it
continues to rise regardless of the state of the input. As long as the
output is true and the Accumulator is counting, additional triggers of
the input do not affect the state of the output or the count of the
Accumulator. Once the Accumulator reaches the preset value and the
Timer resets the output to false, the Pulse Timer can again trigger the
process by sensing a false to true transition on the input contact.
Even if the input remains on the entire time, the Accumulator is
counting. When the Accumulator reaches the preset value, the Timer
resets the output to false.
Timer Elements
Element Description
Pulse Trig Timer - It has a preset value and an accumulator value. The
timing base can be selected as 1 ms or 10 ms.
On Trig Timer (On-delay Timer) - It has a preset value and an accumulator
value. The timing base can be selected as 1 ms or 10.
Off Trig Timer (Off-delay Timer). It has a preset value and an accumulator
value. The timing base can be selected as 1 ms or 10.
Timer Reset Element - Reset the timer element