Re: [CAD_CAM_EDM_DRO] Interfacing EMC with Bandit drives

I compared your step table with mine and see that yours seems to be
what it should be. However my Bandit does just as I listed in my
table. It skips the first state in your table. I don't know why.
Maybe it is broke and I don't know it. It seems to have the accuracy
it should.

Thanks for the suggested circuits for converting step/direction to
make step phase signals. Could you explain the difference between
half step and full step. Why would one choose one over the other?

Jack Ensor

>
> Jon Elson wrote:
>
> > Jack Ensor wrote:
> >
> > > There are 5 input signals to the Bandit driver. The position signal
> > > input consists of 4 opto-isolators. A move signal is coupled to the
> > > 5th opto-isolator which terminates the hold mode. After the move
> > > signal is goes to zero, there is a 5 second delay via a 555 timer
> > > before it reduces the current to the hold level.
> > >
> > > The step signal sequence into the two channels is as follows:
> > > A B
> > > 01 01
> > > 01 10
> > > 00 10
> > > 10 10
> > > 10 00
> > > 10 01
> > > 00 01
> > > repeating beginning with 01 01
>
> I think you left out a state in this table, I have rewritten it, and provided
> a circuit to make the conversion at :
> http://ascc.artsci.wustl.edu/~jmelson/stepdir.html
> Look in the half step link there. I also show a simpler circuit to make
> full step phase signals from step-direction signals. Both of these could
> be reduced to single chips with CPLDs.
>
> Jon