Never expected that saddle on a cow comment would trigger so many
patties ;-)
LinuxCNC is not only about RT kernel as some threads seem to spin around
to no end. It seems that Chris understood my original post the best.
What he pointed out is use of modern technologies that makes it possible
to create advanced systems we could only dream about years ago.
Those of you that have a problem with that please do some research on
industry trends. Then stick heads together and see how much of that
could be built for DIY crowd that fall in the following categories:
- hobby,
- light industrial use,
- advanced industrial use
GNU Linux and other open source software made it through those stages in
early years. In my opinion CNC systems need to be looked at as robotic
devices instead of exotic things that cannot be improved beyond what
LinuxCNC and alike (?) are doing at this time.
This page describes pretty much what Chris was saying I believe:
https://www.mmsonline.com/articles/modern-cnc-control-systems-for-high-speed-machining
"The CNC consists of the following main components:
Operator panel based on industry-compatible PC technology for the
man/machine interface (MMI)
CNC control unit (NCU)
Programmable controller (PLC)
Drive modules for machine tool axes and spindles (feed drives VSA,
and main spindle drive HSA)
Motors (AC motors and linear drives)
Supply and energy recovery unit (S/E unit)
As each drive module, the NCU, the PLC and the operator's panel each
contain a processor, a modern CNC can also be seen as a multiprocessor
system."
That makes it clear that it's CRAZY to use PC motherboard for running
all functions of a CNC system. I see some on this list keep mentioning
PPort; please get off the dead horse or jump the ship!
If I could, I would tell this to Ken Olson, DEC CEO, in the early 90's
when DEC started to deteriorate in the 90s. To fill the gap, there was
at least one manufacturer making PDP compatible boards that you could
plug into PC-AT if I remember correctly. They might be still around.
Architectures like PDP-8, PDP-11, and HP-1000 that I supported long ago
were designed for industrial use: power plants, electric power
distribution, steel mills, etc. Why is that important to bring up here?
Computer architecture. PC sucks! It's based on the 80's 8086 and beyond
that. It was not designed for industrial use in the first place. At
best, PCs were used as dumb terminals to mainframe size computers.
PDP CPU, instruction set, memory, interrupts architecture, and Unibus is
where the magic was. Interfaces/controllers were able to interrupt main
program or OS based on their priority. Critical interfaces in the Unibus
backplane had higher priority; disk drive controllers or DIO over
printer or terminal, etc.
What about LinuxCNC? You want to poll parallel port in a loop and watch
it in fake scope? Count motor steps or it's encoder? Really? Or have
smart motors or sensors tell exactly the tool position? CNC components
are getting cheaper so we can afford more and more of them to assemble
CNC machines or upgrade the existing ones and have LinuxCNC handle all
of it.
CNC systems also have sections that have higher priority than others.
Comparing this to supercomputers is just silly. I don't care what any
individual uses for their work as long as it does not scare the horses.
I admire and understand that those who converted huge CNC machines 5+
years ago want to keep them running 'as is' as long as possible. Some
machines might be used as fully functional museum artifacts and that's
fine too. More power to them.
My interest in robotics made me come across interesting but expensive
solutions in that field. Robots loading and unloading material and parts
are interacting with CNC machines. How would LinuxCNC work in that
environment? Watch GUI? Not easily. Give me a break. Leave user GUI off
the main system!
https://www.universal-robots.com/how-tos-and-faqs/how-to/ur-how-tos/remote-control-via-tcpip-16496/
https://www.universal-robots.com/how-tos-and-faqs/how-to/ur-how-tos/real-time-data-exchange-rtde-guide-22229/
https://blog.universal-robots.com/how-to-get-robots-to-talk-to-each-other
MODBUS anybody?
No need for GUI all the time:
https://www.zacobria.com/universal_robots_zacobria_remote_control.html
Best (???) CNC would be able to run from the pendant like peripheral,
X-terminal or some such as John Dammeyer and Chris mentioned in their
extensive studies on this subject matter.
Thanks to all for extensive research and comments elsewhere. I learned
allot.
I hope this message does not turn into "nuclear thread explosion" like
the other one did. I keep some valuable messages for future reference.
Sorry but top posting, untrimmed messages, and "signatures" that are 20
times longer than the answer don't fit that category.
Think it this way; trim threads to make them easy to read on pocket size
devices so we could use it as a source for project proposal to venture
capital to fund it. Crowd source LinuxCNC upgrade perhaps?
One way to handle ideas for improved LinuxCNC that are sprinkled in
different threads could be collected in a form of CNC-RFC (CNC Request
For Comments). Remember RFCs?
Accounted for inflation; my $2.00.
--
Rafael
$(cowsay)
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
