Chapter 4. Ladder Diagram (LD) Programming
GFK-2950C February 2018 227
ENABLE goes low; Q goes low; timer stops accumulating time and CV is cleared.
ENABLE goes high; timer starts accumulating time.
ENABLE goes low before current value reaches PV; Q remains low; timer stops accumulating time
and is cleared to zero (CV=0).
Operands for On Delay Timer
Warning
Do not use the Address, Address+1, or Address+2
addresses with other instructions. Overlapping
references cause erratic timer operation.
The beginning address of a three-word WORD array:
Word 1: Current value (CV)
Word 2: Preset value (PV)
Word 3: Control word
The Preset Value, used when the timer is enabled or reset.
0 ï‚£ PV ï‚£ +32,767. If PV is out of range, it has no effect on Word 2.
The current value of the timer.
All except S, SA, SB, SC
and constant
Example for On Delay Timer
An on-delay timer with address TMRID is used to
control the length of time that a coil is on. This coil
has been assigned the variable DWELL. When the
normally open (momentary) contact DO_DWL is ON,
coil DWELL is energized.
The contact of coil DWELL keeps coil DWELL
energized (when contact DO_DWL is released) and
also starts the timer TMRID. When TMRID reaches its
preset value of five tenths of a second, coil REL
energizes, interrupting the latched-on condition of
coil DWELL. The contact DWELL interrupts power
flow to TMRID, resetting its current value and de-
energizing coil REL. The circuit is then ready for
another momentary activation of contact DO_DWL.
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