Spindle - Slide Sychronisation

[bobhare]

I'm converting an ORAC lathes electronics and have had the slides under CNC control and the spindle operating at variable speed through a VFD. It's not all integrated and under CNC control but when it is i intend to use Linux CNC but also have Mach3.
The VFD is a Eurotherm 601 and the BOB is one advertised as a Mach3 board with a 0-10V 0utput and a relay. On the non-working end of the spindle is an encoder disc with, i think, 100 slots with one extending to the outside of the disc.
The three images below show the VFD, the BOB and the encoder disc.
I need the lathe for thread cutting and obviously need to sync the z slide and the spindle.
My understanding is that the Encoder sends a feedback signal to Linux CNC which then controls the slide traverse rate to the spindle speed.
I don't know whether the BOB I have can fulfill this task and even if it can i don't know how to do it.
So the questions are:-
1 Is the BOB adequate and if not can someone recommend a more suitable one.
2 How do i build the kit that picks the signal up from the encoding disc and
3 How do i integrate the bits and control it through Linux CNC.