Re: [CAD_CAM_EDM_DRO] RE: question for potential Gecko 320/340 users

Steve Stallings wrote:

> Oops... reading my own post, it was confusing....
> The feedback that I am referring to is the FAULT
> signal, not encoder feedback signals.

Ah. You might look at my current scheme, see the first
schematic on http://pico-systems.com/EMC.html for the
entire emergency circuit. Most of this is to handle the
quirky watchdog timer function on the Servo-to-Go
card. There is a current loop running through a chain of
normall closed contacts on e-stop buttons and relay
contacts in the servo amps. When any contact opens,
it breaks the chain, and an opto-coupler detects this
and commands an E-stop through hardware. It signals
the comuter an E-stop has happened, but it also kills
+5 V power to the Opto-22 rack, so that the spindle,
servo power and coolant, etc. is shut off.

There is a green LED that is lit whenever the safety chain is
closed, so when it doesn't come out of E-stop, you can
tell at a glance that the chain has a fault contact open
somewhere.

I have incorporated the same logic into both my PPMC servo
card set and the universal stepper controller card.

Jon