Rockwell Automation AutoMax Enhanced Ladder Language Reference Manual - Manual (Page 42)

3Ć2
Guidelines for Programming Timer Instructions
D When inserting timer instructions into a program, assign unique timer variables to
each timer instruction. Do not use the same timer variable on more than one
instruction in a program. However, you can use individual timer elements (name.Q,
name. Elapsed, etc.) as variables on other contacts and instructions.
D When you remove a timer instruction while testing your edits on an online, active
program, the Editor considers the timer instruction as being disabled. Therefore,
should you ever reĆinstate that timer instruction, it is inserted into the program in a
reset state. This means that the timer has lost its accumulated time.
I MPORTANT
Observe the following programming practices when creating ladder programs:
D Avoid using timer instructions in programs that are not executed at periodic intervals
because their behavior will be unpredictable.
D Avoid skipping timer instructions using a JMP instruction because the timer's output
will not be set unless the timer instruction is executed.
D Do not use timer instructions that use the same global, timer data structure in
multiple programs because the timer will gain time.
D You must enter global timers into the variable configurator as fiveĆelement, double
integer, nonĆvolatile arrays. Example: TIMER1!(4).