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stop or hold program correctly
« on: January 22, 2020, 09:56:55 AM »
Hello,
A G- code prograI have to relive and reset the zero points. It is very annoying. So far I have been helping myself to save the zero point position with "remeber position" in order to find the zero point again.m is processed. I have to press the stop button for some reason. When I run the program again (even after the Rewind program) the machine has forgotten its homing data.  What can I do better?
thank you in Advance!
Reinhard
Re: stop or hold program correctly
« Reply #1 on: January 22, 2020, 01:22:05 PM »
Hi,
if you press <Stop> or <Enable/Disable> the machine will crash stop and lose reference.


If you wish to avoid losing reference press <Feedhold> then <Stop>. Feedhold allows the motion commands
in the buffer to be executed and then stop once the buffer is drained. <Stop> without the preceeding <Feedhold>
aborts and discards any motion commands in the buffer.

Craig
My wife left with my best friend...
     and I miss him!
Re: stop or hold program correctly
« Reply #2 on: January 23, 2020, 04:06:53 AM »
Thanks for the answer.
So Feedhold is the only way to stop the program without losing steps or mispositioning. Even if the tool does not stop exactly in every case.
The decision as to whether a feed stop is enough or a stop must be very quick. That’s a problem. Was that also the case with Mach3?

Reinhard
Re: stop or hold program correctly
« Reply #3 on: January 23, 2020, 01:18:52 PM »
Hi,

Quote
Was that also the case with Mach3?

Yes.

It is a problem with ANY buffered CNC program, that is any program that uses Windows. Because Windows is not and cannot
be a realtime system it MUST be buffered. Now if you EStop the contents of the buffer are aborted and the machine loses reference.

With Mach4 the default buffer length is 180ms. At any given time the buffered PVT motion commands will be 180ms or less. You can program the buffer
to be shorter (or longer) but then risk the buffer draining and then you get a 'run out of data error'.

Craig
My wife left with my best friend...
     and I miss him!
Re: stop or hold program correctly
« Reply #4 on: January 24, 2020, 02:52:59 AM »
craig
the bigest cnc for woodworking in europe (Homag,Biesse,Scm,..)they all use windows as real time
the use software for that ,Tpa use "RTX"  biesse use "Intime"...etc
i wonder if can do same with mach?
Re: stop or hold program correctly
« Reply #5 on: January 24, 2020, 03:44:38 AM »
Hi Katz,

Quote
they all use windows as real time
the use software for that ,Tpa use "RTX"  biesse use "Intime"...etc

Yes it is possible to have a realtime core running concurrently with Windows. Interval Zero have a solution called RTX.
Note that it is a realtime core, it is not a Windows core. That is to say that Mach4 would not run run in it but rather a
specially written subset of Mach4.

I investigated doing exactly this some years ago. The cost at that time was $16,000USD for the development software and tools
and then EACH system would require a runtime license at additional cost.

If you have followed the Ethercat development of Mach4 then you would see that Kingstar have partnered with Interval Zero
to craft an RTX realtime core that enactes realtime communication that Kingstar have made into an Ethercat Master.
The video banner of the Mach forum is of a Matsurra VMC making a part. What may not be obvious is that it is Mach4 as an
Ethercat Master, which is by definition realtime, and running Windows!!!!.

So yes it is possible to make Windows 'realtime' and its being done right now, its just that it is not really in the realm of the hobbyist.
I suggest you ask NFS, who will probably turn you to Kingstar, and ask about a price. My understanding is that if you buy the Kingstar
Ethercat software it includes the RTX runtime license.

Craig
My wife left with my best friend...
     and I miss him!