jvaldes
High resolution encoders is not all about resolution of the machine. Depending on the servo drives and the speed it can react to the encoder then it may well produce a much smoother and cleaner motion if you have a higher count encoder. I posted some pics a while back in another thread showing the difference of a motor I had with a sine/cosine encoder. I could interpolate the encoders counts and by using a higher number and no other changes the drive could keep the motor on track much easier.
Andy,
Depends, likely your drives have electronic gearing in them, that means you can have less steps per unit in Mach but the drive will multiply that and make the motor move the correct distance. Its not a method I personally like but it can allow you to get more performance from your hardware when using the parallel port. Well when I say performance really I should just say Velocity as your motion may actually suffer slightly, especially at very low speeds.
Hood