Re: [CAD_CAM_EDM_DRO] Black box again

Tom Eldredge wrote:

> Gentlemen,
>
> Some time ago we were discussing the "black boxes", Pic controllers etc. I haven't heard much from the guys who said they are working on these lately. I think there is still interest in having a "black box" that one could serially send motion commands to, which would do some spooling of the serial commands (enough that the black box could smoothly output the step and direction pulses in real time). This would free our PC's to do other control functions. Such boxes would only need (in my opinion) to be able to to the above, and to be able to be called (interrupted) to a controlled stop during a move. If a move was interrupted, the black box would report back to the control which move was interrupted. The control could then use encoder feed back to decide what to do after any interrupted motion. I know there are some IC's out there which will do part of this. I would like to see some black box capable of handling a move of about + - 320,000 steps in one move, in order to give a
> resolution of a tenth of a thousanths of an inch, and 32 inches in any one direction from a zero point. I think this would cover the distances most of us would need to cover in our lathes or mills.
>
> I think the serial port is going to be with us for a long while.
>
> Some time ago, I programmed a Basic stamp (SX) to do most of this, but it was too slow and was limited to 32,000 steps. It would also be possible, in my opinion to do the proportional math with the PC for the various axi involved in a particular move, and the command could include specifications on whether the controller should accelerate and/or decelerate the moves to relieve the black box from having to make this decision.
>
> I am also aware that this is exactly what LP indexer does through software, but I consider that an expensive proprietary alternative. I also own a copy of LP indexer, which I am not using at this time. I would like the hardware alternative better. Microkenetics used to say they were planning to have a product like this, but I gave up waiting on them.
>
> Is there anything seriously missing in this "wish list?"

I just can't understand why you keep wanting to re-invent the wheel,
when a really nice wheel is already working for so many people!
My 'black box' uses the parallel port, a lot faster than serial. It
gives you the choice of stepper or servo operation, and can do
open-loop or closed-loop steppers. It can go to about 300,000 steps/second
if you really need that speed. I have several customers very happily
using it now.

Jon