The guy you are talking about would likely be Dave DeCausin (sp?) one of the founders of Fadal.
Yes the drive is a DSD but it needs to be capable of Indexing, the standard drives wont do that.
I talk via the PLC and the ladder has most of the integration in it for the unclamp/rotate/clamp timing. If you simply just wanted to index you could simply have some inputs and it would index to the selection you called.
The inpouts are seen in the drive as follows
Pre-Select 0 = 1
Pre-Select 1 = 2
Pre-Select 2= 4
Pre-Select 3 = 8
Pre-Select 4=16
Pre-Select 5 = 32
So as you can see depending on which inputs you use you can select any of the 64 index positions, well really only 63 as index 0 is not really valid for this operation.
You also need an input set up as Start Index and likely Start Homing, also you may have Reset Drive or whatever. The drive has 8 digital inputs but the nice thing is you can set them up for multiple uses. That means if you are doing an operation that requires two inputs you dont have to waste two inputs if they can legally be seen by the drive at the same time, for example you could have the start Index set up with the Presets.
Have attached a few screenshots of the drive setup, first shows the Index presets I have set, have opened the first three positions so you can see the configuration in the drive.
Next is the Inputs, as you can see I only need 4 presets as I only have 12 positions so there is no need for me to double up on the inputs.
Last is the outputs setup.
Heres a vid of my first tests with the turret I made from scratch (well curvic coupling wasnt home made

)
http://www.youtube.com/watch?v=hRTfxuXf6ykHood