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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