NOTES on Handwheels

Hi,

I just have a few questions regarding what I said earlier.

I have not studied the EMC software yet, and I don't have anything
to run it on. ( don't have money for it yet )
But as I understand it, - the encoders and other inputs are first
copied to the shared memory area ?
Then the motion controller in RT space reads it back, and process
it ?
( I guess the step counters do the same )
If so, then a semaphore array in shared memory, could be used for
multiplexing the registers. ( I have not studied the RT/EMC
interface, but I would have all the variables to the RT controller ,
mirror it's values to shmem before output ) The RT module reads this
first, and will find out what values to use. This way you would have
easy access from process space.

Forgive me if this is too obvious, but I just thought this kind of
interface could be used in a number of ways. ( or am I just stupid
now ? hmmm ..)
In the case of handwheel, it should be easy enough. When operated,
it reads the current contents from the axis, while it always zero
out its own value. This will not cause any misbehavior on the axis
controller. ( you can't switch over to handwheel, if the axis is
moving )

I don't know, maybe you could have some user G&M codes, you could
insert into the "G-program", and override an axis with the
handwheel. Say you wanted to drill some holes. Let it run to the
location, then have a cycle stop. If a handwheel code was inserted,
and you run cycle start, then it would read the handwheel - you
would manually lower the bit, and the commands for that axis in the
program, would just be skipped. Next cycle start, would just
traverse to next hole location.

Here is something else, - I mentioned a digitizing and output
files. A nice thing would be to have a module that would read the
the stuff, and dump it to a file as G-codes. Any feed rate over
rides you do, would be saved in this file. Maybe with selected parts
where you used the handwheel too. Anyway, - if you try to make a
part, and you had to slow down the feed rate some places, then a
"learned" file output, could be used as input the next time.

Just forgive me if I am expressing stupid or common stuff, - as I
haven't operated anything yet !

( anyone have a job for me ? I sure am frustrated, having no
machine available :-)

//ARNE