[raychar1234]

Hello,

I recently switch to use emc2 from Mach3. I am totally a newbie in this software. I am currently designing a diy machine and need to have the functions:

i) to pause an executing cutting process by an external button A when it is tied to high voltage (~+5v)and resuming the process when this button is tied to low voltage(~0v).
ii) to reverse a number of executing steps (let's say 50 steps backward) when an exteranl button B is tied to high voltage.

Can they be achieved by this software and how can it be implemented. Hoping that somebody can give a hand and some hints.

Thanks in advance.

[chester88]

The first one yes. motion.feed-hold pin
The second one probably not. are you meaning to go back 50 steps of gcode ?

[raychar1234]

Hello,

If you have, could you send me the codes to achieve the pause/resume functions.

Another function just likes rewinding a video tape. After the pause, going backwards a number of step. I read through the manual, it seems not having this function? Is there any other approachs to achieve it?

Thanks,

[chester88]

from the manual:
Core Components
motion.feed-hold - (bit, in) When Feed Stop Control is enabled with M53 P1, and this bit is TRUE, the feed rate is set to 0.

so if m53 is set then linuxcnc will respond to the motion.feed-hold pin which you could connect to a physical input pin that is connected to a switch.


stepping backwards through Gcode is not currently possible.
If you wish to discuss work arounds (which I don't think there will be, but would need to know more about what you are doing) you should join the linuxcnc maillist and ask there.
The hardcore developers hang out there.

Chris M