Re: [CAD_CAM_EDM_DRO] Turbocnc and Limit Switch

Hi Frank,

The Gecko's need their own power. You don't want to "steal" it from the
Parallel port pins, that won't work. Take it from a separate supply
(wall wart), or from the PC's joystick or keyboard connector power pins
(see previous threads).

I would think that if the + travel and - travel limits are SEPARATE
inputs to TurboCNC (I haven't examined the product), then you'd be
allowed to move in the opposite direction!

A pull-up resistor of 1-10K, from the "input" pin to the aforementioned
+5v, should be what you're looking for. This guarantees a high level
signal when a switch (+ limit sw's connected in series, - limit sw's
also connected in series on separate circuit) "opens". The sw circuits
n/c contacts "pull" the "pulled up" input pin low, if both (2 axis)
switches are closed.

This ASSUMES that TurboCNC allows this "active high level" for the limit
signal. Wired in this fashion, an ACTIVATED SWITCH, broken wire, or
broken switch should give you a LIMIT error (active HIGH signal), when
the input pin goes to +5v!

The "broken stuff" means you a little added protection, when and if the
wires or switches get damaged! Otherwise, you might not notice the
damage until TOO LATE!

The Gecko's don't need much current, neither will the pull-up resistors
and limit switch circuits.

Please verify this in your manual before implementing. SAFETY FIRST!
And make careful tests and make your OWN DETERMINATION if this is
suitable for your hardware/software!

Hope this helps.

BTW, there is also a C5 list!

emcocompact5users@yahoogroups.com


Alan KM6VV
P.S. We'd like to hear the results!


rudolphs@... wrote:

>
> Hi,
> I'm working on converting a Emco Pc 5 Lathe , I'm using
> Turbocnc and Gecko 201's .
> What is the best way to hook up limit switches ?
> Right know I have the software set up to sense activation
> when that switch is going low (to ground) .
> I need to have some way to reset this condition
> so I can proceed with the movement of the motor .
> Also I noticed that setting them this way seems
> to put a drain on the available voltage to the drive's
> I'm not using any pull-up resistors ,
> (not really sure how to wire those).
> Any help or ideas would be great.
> Thanks
> Frank