On Fri, Sep 25, 2015, at 12:00 PM, Gene Heskett wrote:
> > What I was hoping for, without hacking up some hal memory, was that > motion was aware of a switch closing and opening if it went by them in > normal programmed motions, and was recording which direction the machine > was moving the last time the switches opened. That could then be > consulted when the home all command was issued, to determine which side > of the switch it was on, and that to find it, it needed to move toward > it, then once found, the normal 2nd & slower phase of fine tuning the > home would then be resumed. All that would take is the sign of the > motion, which could then be used to diddle the sign of the > HOME_SEARCH_VELOCITY. This cannot work. Remembering where you are while running is one thing. Starting up is another. When the machine is powered up it has no way of knowing which side of the switch it is on. Storing the info somewhere is not the answer - maybe the axis was moved manually (or even completely disassembled for repairs) since the last time the control was powered. If the control doesn't know which side of the switch it is on, an attempt to home has a 50% chance of running the axis into the hard stops. Maybe no big deal on a bench-top stepper machine. Completely unacceptable on an industrial class machine. The proper answer is a long actuator for the switch, so that once the switch is activated, it stays activated all the way to the end of the axis. -- John Kasunich jmkasun...@fastmail.fm ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
