On Thu, Oct 30, 2008 at 07:28:16AM +0000, Chris Morley wrote:
> 
> What I am saying is that while using CSS , before STARTING a feed line
>  EMC should know that the spindle is up_to_speed . I suggest that a HAL 
> bit pin (say spindle_up_to_speed) would suffice. Then an integrator could
>  connect that pin to what ever logic he wants to confirm that the spindle is
>  up_to_speed (and how close up_to_speed should be). It can be done in
> other less direct ways but I think that such a fundamental behavior
> should have a direct, clear pin for it.  

I see what you're talking about now - and I agree that an at-speed
input which EMC checks at the "right" times would be a nice addition.

I think possibly the "right" times are:

1) before the first feed move after each spindle start, AND
2) before the first feed move after each spindle speed change, AND
3) if in CSS mode, at every rapid->feed transition

I propose this as the spec -- please tell me if you agree or
disagree with it.  (I do not know how to implement it yet, but
that's secondary to agreeing on the correct behavior.)

> For instance for the spindle reverse I would monitor spindle fwd and rev
> If they switch  I feedhold to do the brake and reverse.

If we have the above behavior, is it true that using feed-hold for
waiting for the spindle to do various things, and all the issues about
feed-hold that arise when we think about using feed-hold that way,
are moot?  No matter how long ladder takes, and what it does, to get
the spindle to agree with motion's requests (fwd, rev, speed), it
asserts at-speed when it's ready.  If EMC's motion waits at the
"right" times (above) I think we've solved all the problems.

> Sorry hope thats better is there away to make Hotmail do this automatically?

Much better, thanks.  Sorry - I have no clue about hotmail.


On Thu, Oct 30, 2008 at 09:16:21AM -0500, Steve Stallings wrote:
> Regarding pause when reversing spindle (direct M3 to M4 transition),
> this is a behavior that will differ from machine to machine. All such
> behaviors should be accommodated with HAL setups or Classic Ladder.
> Early implementations of EMC had Bridgeport specific behavior
> embedded in the C code such that an edit and compile was needed
> to change the behavior. This severely inhibited progress in adopting
> EMC because many users were not able to accomplish this task.
> HAL and Classic Ladder are much easier for machine integrators
> to work with and are the right place to address machine specific
> behaviors.

I agree with Steve here.  The bridgeport-specific behavior hardcoded
in EMC had brake delays, "go faster"/"go slower" to be hooked to the
varispeed air motor, etc.  I think it was the right decision to
remove that stuff from EMC proper and let the hardware abstraction
layer handle it.  That really was the whole point of HAL.

Chris

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