Timer and Counter Instructions

Timers and counters control operations based on time or the number of events.
Available Instructions
Ladder Diagram
Function Block and Structured Text
If you want to
Use this instruction
time how long a timer is enabled
TON
time how long a timer is disabled
TOF
accumulate time
RTO
time how long a timer is enabled with built-in reset in function block
TONR
time how long a timer is disabled with built-in reset in function block
TOFR
accumulate time with built-in reset in function block
RTOR
count up
CTU
count down
CTD
count up and count down in function block
CTUD
reset a timer or counter
RES
The time base is 1 msec for all timers. For example, a 2 second timer’s .PRE value should be 2000.
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