Re: know your limits

["William Scalione" <wscalione-at-nc.rr.com>]

Bill

But in the case of normally open switches, that is what we want.
If any one of those axis switches closes it will signal the EMC
that one of the axis' (axi??) has homed. Since the EMC has only one
home input, you must move the axis off of the switch after homing
in order to home any other axis

Now if we used normally closed switches and changed the polarity
of the homing input in the EMC ini file then you are right and wiring
them in series will produce the same result. Come to think of it,
I never did ask Ian which type of switches he was using, So Ian
if you are reading this, normally open switches in parallel and
normally closed switches in series.

On limit switches it is probably best to use normally closed
switches, as a broken wire or bad connection will fault the EMC
as a tripped limit switch. With a normally open switch you won't
find out that you have a bad wire until the X Axis slams into the stops
or worse yet, falls on your foot. I suppose using normally closed
switches as home switches makes sense also, but not nearly as
critical as limit switches.

thanks for the clairification Bill.

Bill


>
>
> <<
>  Also, in re reading your original post, I see you have the switches in
>  series?
>  Change to parallel as all switches must be closed in order for series to
>  work.
>  In the ascii art below || represents a switch
>
>
>
>                     |----------||----------|
>  Pin 12 ---------|----------||----------|-------to parallel port ground
>                     |----------||----------|
>   >>
> My electronics training indicates that you will get an open circuit only
when
> all three switches are open, you will not be able to detect the opening of
> any single switch if they are in parallel.
> bill
>