RE: [CAD_CAM_EDM_DRO] Re: Wiring diagrams,

Donald,

I think you are trying to make it harder than it really is. If you are
looking for step by step hold your hand instructions, you are right they
don't exist except in the expensive commercial packages. If you are trying
to learn how this stuff works then you have the information in front of you
already.

I will try to answer your questions below.

> Tim,
>
> This makes a good starting point but doesn't really explain how to
> hook up homing switches let's say. EMC uses one pin (pin 12(S5)) for
> input of homing. Where is the input coming from on the other side of
> the switches?

It has to complete a circuit so it can be pulled high with a 2.2K resistor
(A 10K will work fine or about anything in between) from a common 5V source
and then the opposite side of the switch goes to ground. This would be the
most common hookup. You could also pull it low with the resistor to ground
and then hook the other side of the switch to a common 5 V source. For EMC
either would work as you can set the sense bit to be high or low.

> How are the switches wired? Series, parallel, or
> series/parallel? It don't say. And I can't find anything that does
> say.

Think about it, it has to be parallel. Otherwise you would only get a home
signal if all switches were closed at the same time. Imagine, X is open and
you are trying to home Y. The machine would just keep going and rip the
switch right off.

> The DANCAM drawing shows the homing switches grounding pins 12 and 13
> as they close but with pin 11 (N.C. for DeskNC) being inverted I
> assume it goes high when the switch is opened for DeskNC?

All of them are high when the switches are not tripped due to the pull up
resistor. When the switches trip the corresponding pin goes low. The
difference on an inverted input is the computer sees the high as a 0 not a
1. The software knows this and handles it accordingly.

> There is too much confusion here and that is why I'm making the
> suggestion for wiring diagrams.

Now with your new knowledge are you willing to make the wring diagrams?? I
will be happy to add them to my site or the FAQ as appropriate.

Tim
[Denver, CO]