Kinetix 300 Master Gearing Question

I would like to turn a servo motor (slave) relative to the motion of a slide.  The slide will be moved with a hydraulic cylinder.  I would like to attach a linear encoder to the slide and make that encoder the master.  The manual only shows a connection between two servo motors.  I assume that this can be done with just one and an encoder?

Does anyone know if there are any specific requirements? 

Most linear scales are 5v.  Does it need to be 24v?

I don't know much about encoders but the manual shows connection points for A+, A-, B+, and B-.  Seems straight forward enough.......(famous last words)