The drivers are most likely analogue drivers and accept +/-10V for the velocity reference.
The linear scales are connected to the CNC controller, and the motors are most likely working open loop? with the cnc controller closing the position loop?
If this is the case, your options are as follows with the best option at one.

1) get a new cnc controller that will accept the scales and give +/-10V as a velocity reference.

2) Buy new servo drivers that can accept the linear scale and have the driver close the position loop, and connect to you PC with a smooth stepper and Mach 3

to be honest i would forget using a PC based solution and opt for the cnc controller.
If the existing motors and drivers work the CNC controller will be far cheaper to do, and will perform so much better.


Quote Originally Posted by bodgeitandscarper View Post
Thanks Gary this system has proper servo amplifiers, motors are rated @150nm.But it has linear scale for position feed back to the control. The machine is made by rambaudi. The control has breathed its last breath spares are hard to come by so a new pc based control it has to be. Its the closed loop bit I need to who does what.