ATC Tutorial?

Is there a simple ATC Tutorial?  I have a 12 pocket carousel style changer.  I'm attempting to pick apart the sim_vmc for the pins and components I need, but I'm getting very confused with the drawbar.  I think I figured out the carousel, but I'm not sure.  Thank you

Ikeep meaning to write one, but I am rather hampered by never actually having owned an ATC.
(However I did write the Carousel component and have worked on setting up a couple of ATCs with LinuxCNC)

Generally I would suggest using a remapped M6 to handle the axis and actuator motions in G-code. It's not the ideal programming language but it makes abort behaviour cleaner (as the ON_ABORT routine will be called)

Look at the subroutine in the sim_vmc for an example of how to interlock actuators and limit switches.

the best thing to do is to layout your atc mechanical setup for indexing the pockets, this will help you determine which method is best to control the platter position.

then list out all of your sensors, then compare them to the subroutine file connections.  its hard to go much further helping wihtout more information on your part.