Re: Manual Pulse Generator (Handwheel) for EMC

> From: "Tim" <luvindaddy@...>
> Subject: Manual Pulse Generator (Handwheel) for EMC
>
> Hey Everyone,
> I've got a question for Jon Elson & Ray Henry..... and anyone else
> that may know??????
>
> Jon, Does your "Universal Stepper Controller" handle input from a
> manual pulse generator? Selector switches for axis & step rate,
> handwheel for direction?
>
> Jon & Ray, Is "EMC" capable of handling this type of external input?
> or does "EMC" really not care/or have anything to do with it?

Hi Tim

Certainly Jon's encoder board will read an encoder or quadrature based
handwheel -- not all of them are. EMC will treat that as an ordinary
axis so you will need to set the soft limits and following error very
large so that it does not expect much control over whatever is "driving"
that encoder.

What you do with the position maintained for that axis is another
question. We were able to get electronic gearing written into the motion
code last summer but we don't have easy access to it from the GUI just
yet. That has kinda been hanging fire until the low level rewrite - EMC2
- is completed. IMO electronic gearing is the only way to run a
handwheel. Well the only way that would satisify a machine service guy
like me.

For now it would be possible to run a handwheel from a GUI like "mini" if
we added a process that read the offsets for the handwheel axis and
formed proper mdi commands from them. This process would also need to be
able to ignore handwheel offsets when it was not being used. We'd need
to add some buttons or keyboard bindings to control the pulse multiplier.
With a bit more work we could also make machine speed responsive to the
size of the handwheel offset as well. This would not be real time but it
would be there.

Ray