Re: [Emc-users] HAL components and functions

[Stephen W. P. <sp...@so...>]

David Winter wrote:

> Steve,
>            Thanks for owning up to not writing the man page for
> mod-dir but I would like to know what it does and how it works please.
>  
>                              Thanks in advance,
>  
>                               David Winter.

Oh, that :)

It chooses the shortest path from "actual" to "desired" positions.  
There are parameters for min and max values, and whether it should wrap 
around (ie, increment past max = min and vice versa).  It is used to 
move the toolchanger to the target pocket using the fewest moves.

The parameters are:
min-num:  the minimum position value.
max-num: the maximum position value.
wrap: whether or not to wrap the count or clip to min/max.

Input pins are:
actual: the current position
desired: the desired position

Output pins are:
up: true when actual needs to go up to reach desired
down: true when actual needs to go down to reach desired
on-target: true when actual==desired

Hope this helps
- Steve
(maybe I should copy this email into a manpage ;) )