Rockwell Automation DeviceLogix System User Manual - Manual (Page 38)

38 Publication RA-UM003B-EN-P - February 2010
Chapter 2 Navigate the Function Block Editor Interface
If the device supports retentive type Timer or Ccounter, then the
accumulate value of the Timer/Counter will be retained during
power-down. When the power is cycled and the logic resumes
running, it updates based on the previous accumulate value.
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. For each time base 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 time base 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 again begins to
increment the accumulator if the reset line goes FALSE while the input
remains TRUE.
The valid data ranges are as follows.
Parameters Data Range
PRE 0 ~ 65535
ACC 0 ~ 65535
Time Base 0 (1 ms), 1 (10 ms)