PID servo control

[R.thayer]

From my understanding one can drive servo motors using emc. I would like to learn more about pid, sending the encoder signals back to computer, and pwm signals from emc. Can anyone explain any of these to me. Can anyone explain what files I will need to use to drive servos. Any information about do this would be great. Thank you for your time and hope to hear your ideas and thoughts soon.

[samco]

There are a bunch of ways emc can do this. the most simplest is what I was doing.

there are a few examples to look at.
http://cvs.linuxcnc.org/cgi-bin/cvsw...servo/etch.hal
This is the etch-o-sketch. It is using the printer port to read in encoder count and also to send out the pwm signals for the servo.
http://emergent.unpythonic.net/projects/01142347802

You have seen my post doing something similar. I actually started with the etch-o-sketch hal and ini files and hacked them to do what I wanted to do. But as you noticed - I have ended up going with pluto and mesa interface boards - I just wanted to be able to use higher count encoders.
http://www.cnczone.com/forums/showthread.php?t=25929

as far as pid loop tuning - it is something you just need to do to learn. I am no expert and am learning as I go. You could get on irc.freenode.net channel #emc. There are usually a bunch of users and developers that can answer questions.

sam