Request for comment - G320 wiring part II

Thanks to all who have responded to my request, and special thanks
to Jerry Jankura for the extra time.

After some consideration, I have revised my schematic slightly, adding
the ESTOP output to the PC as well as "simplifying" the ESTOP circuitry.

This simplification involves nothing more than rewiring the relays such
that engaging the ESTOP switch removes power from the relays. The first
version had the PIC reading the ESTOP switch and the PIC then removing
power. This version should be more failsafe as a result.

As pointed out by Jerry, this is not a be-all and end-all ESTOP solution.
The total solution would require the lathehead/millhead motors and any other
motion causing device also be stopped when ESTOP is activated.

That solution, though, is beyond the scope of what I wanted to produce.
Such a controller would have to be somewhat customized to the machine in
question - single phase Sherlines being pretty different in their electrical
requirements than gantry mills.

Here again is the revised schematic.

http://www.sfu.ca/~beer/G320.pdf


Alan








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Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta