Re: G340 enable/disable

> I am having difficulty coming up with a circuit that senses the status of the enable/disable pin
> on the Gecko G340. Specifically, I want to sense, through one line, when one or more amps have
> gone into fault. A CD4011 quad NAND gate would do this nicely but that would essentially tie
> the 5V supplies of all four amps together, which Mariss advised me to avoid.
>

I don't have the documentation in front of me, AND I STILL haven't
wired up my G320s purchased around Christmas, so take this with a grain
of salt.

I'm assuming you want this circuit to feed an EStop input on the
controlling PC.

IIRC, there is a circuit in the documentation that shows an external LED
being lit under a fault condition. Why not add an opto-iso in series
with each these external LEDs ( suitably reducing the series resistor
value ).

If you use a transistor-style opto-iso, you can connect all the
emitters of the opto-isos to the ground of the PC.

Next, connect all the collectors together, and run that ( now isolated )
junction to the EStop input of the PC.

Finally, also connect the collector junction to a resistor. The other
end of this resistor goes to +5 coming from the PC. Ta-da.

If you want a further refinement, add an LED in series with this last
resistor, to indicate a global fault.

Alan

--

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