RE: step-motor controller/driver connection

['Larry W. Finger' <FINGER@gl.ciw.edu>]

> Re controller <--> driver cabling
> 
> % Gerd Rosenbaum suggests DB-25 instead of DB-15

============================ snip ==========================
> 
> ==========================================================
> VME58 <--> (New Step Pack OR isolated motor drivers)
> ----------------------------------------------------------
> Pin	Dir Function		Pin	Dir Function
> ----------------------------------------------------------
> 1	Out step +		14	Out step -
> 2	Out direction +		15	Out direction -
> 3	In  high limit N.C.	16	In  high limit N.O.
> 4	In  low limit N.C.	17	In  low limit N.O.
> 5	In  encoder A +		18	In  encoder A -
> 6	In  encoder B +		19	In  encoder B -
> 7	In  index +		20	In  index -
> 8	In  home 1		21	In  home 2 (coarse index)
> 9	In  driver fault	22	Out auxiliary
> 10	In  overtravel		23	    uncommitted
> 11	    uncommitted		24	    uncommitted
> 12	    uncommitted		25	    uncommitted
> 13	    ground/shield
> 

I agree that the functionality possible with DB25 more than overcomes 
the difficulty with real estate.  I suggest, however, that the 
uncommitted pins be assigned (in decreasing priority) to pin numbers 
1, 13, 14, 25, 3, 12.  With this scheme, any cuts on the edges of
ribbon cables have to be deeper to break a needed conductor.

Larry