Introduction.

Workshop PG5
Project management
Use Timers in a
SB:
Timers and Counters from the Standard Library
aren’t made for the use in SB’s. They are designed
for use in COB’s which are executed cyclically over
and over again. If you want to use timers or counters
inside a SB, use the ones from the “Graftec” family.
They are especially designed for Sequential Blocks,
because you can load them in one step and question
the state later on in another step or transition.
What we do in our program is:
Turn the output on and load the timer in the step and
then we go on to the transition where we wait and
question the timer until the time elapsed and the timer
has come to zero.
Repeat the step
and transition for
the time were the
pulse is off:
The Step 2 and Transition 2 are the same as step1 and transition 1:
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