Re: [CAD_CAM_EDM_DRO] Step and direction conversion to + - 10v dc

brunoian1127 wrote:

>On some servo drive units the input requires + - 10v not step and
>direction. Is there a unit (inexpensive) that can had to either
>convert the step and direction to + or - 10v ... or that outputs +
>or minus 10v dc to run this style of drive that will work with
>controls like desknc, mach1 etc?
>
>

Rutex makes a converter from step/dir to analog servo.

Also Servo-to-Go and my company (Pico Systems) make interfaces to
control analog servos. My interface is external to the PC, and connects
to it throught the parallel port. Drivers for EMC are on the EMC CDs.
See http://jelinux.pico-systems.com/PPMC.html for more info on this
product.

Unfortunately, programs that were built from the ground up for
step/direction
only, are not easily converted for use with analog servos, other than the
step/dir converter route. Note that the Rutex converter (R991H) only
guarantees
that the motor is within +/- 20,000 steps of the commanded position!
I can't understand why they would make the "lock range" so large.
With resolution of .00005", that still covers ONE FULL INCH of
following error!

With a true closed-loop-to-the-PC servo system like the STG or Pico
PPMC, the computer has a position reading in real time of the actual
machine position, and can decide whether the error at any instant is
too much. You can also get a DRO-like function, with actual position
on the screen at all times.

Jon