Thoughts on Gcode interpreters and CNC controls....

Group,

Since there's a fair amount of CNC knowledge in the group I'd like to
throw out a topic for discussion.

A typical CNC controller operates on Gcode programs in what would be
called an interpretive mode. As opposed to having an already
compiled CNC program to work from. In other words it scans through
the program as it's executing it and forms the motion commands in
real time. Sometimes it's obvious that this method slows down
program execution, especially when you're trying to do continuous
contouring using cutter comp on slower controls. An example would be
Ahha, I saw a wood router guy trying to contour with cutter comp and
it was a disaster because of the micro dwells between code blocks.

My question is, why don't controls have an option to pre-scan a
program and by accessing the tool and part offset tables pre-calulate
all the cutter paths so that when actually cutting all the controller
has to do is deal with interrupts and motion control? Or do some
controls have that ability? I've asked this question to a number of
sales engineers at trade shows, but was never sure any of them
understood what I was asking. The nearest I came to getting an
answer was from a Mazak engineer who thought Mazatrol had something
like that.

Any thoughts?

Thanks,

Doug