You can use them where you need a variable
check - If you want to skip a timer event,
you can check a flag in your main macro, if
the flag is not set then continue running
your macro. If the flag is set then run a
different macro clearing the flag. A third
macro can be used to set the flag. It is
the same as If-Then-Else programming. If
you have a motion detector (which will
always send a trigger signal) the flag can
be set and checked to only execute the
macro once rather than everytime motion is
detected. The flags can be defined as
anything you want to keep track of and
check.