Dedicated mb for PID

The current methods of converting S/D pulses to servo control use analog
tuning of the PID (or PD) loop. Gecko 320/340 amps do this quite well.
Rutex has a board that will convert S/D to +/-10V for use with most other
servo amps.

Suppose a person wanted to do the PID in software. A dedicated PC
motherboard could be used to read S/D pulses from the control computer and
compare this to encoder position via a camtronics card. Servo output would
be through an analog output card, also in the dedicated MB next to the
camtronics card. Software for the PID MB would reside on a Sandisk
Flashdrive.

Assuming the motherboard was free, this arrangement would cost about $250
which is less than four Rutex boards (one per axis). It would also allow
one to vary the permissable following error.

Doug