Re: "dumb box" project[s]

Steve,

No, not directly, but that's understandable - the wording isn't
particularly clear there.

Indexer LPT is a software driver to make the step & dir signals
happen on the parallel port. The PC clock is still used for timing.

This "dumb box", however, is a fancy pulse generator linked to the
serial port (where your mouse goes). It gets rate commands over the
wire, and then generates the pulses on its own output bus.

So that phrase really should be "Replacement of the PC parallel
port Step and Dir driver", since the dumb box alleviates the need to
use the parallel port at all for motion control.

Now, if someone wrote a general purpose driver for the dumb box so
that high level languages could use it easily, then the new driver +
dumb box could pretty much replace Indexer LPT. But the intent with
the 900-000 is to relieve the computer of having to handle all the
pulse generation itself. The command structure and design philosphy
are quite different.

I hope this sheds some light on the subject. If you need more,
feel free to reply off-list.

Dave Kowalczyk
Everett WA

--- In CAD_CAM_EDM_DRO@y..., scy@v... wrote:
> Hi, Dave
>
> The data sheet you referenced on the "dumb box" claims it is a
($76)
> "low cost hardware replacement of the PC LPT Step & Dir driver".
Are
> they being coy - do they really mean replacement for ($250) Indexer
> LPT? And if so, is it intended to work with the same set of
commands?
>
> Steve Clay-Young
>
> --- In CAD_CAM_EDM_DRO@y..., dkowalcz@d... wrote:
>
> > For those who don't feel like clicking around to see what's
going
> > on, here are the basic specs for the "dumb box":
> >
> > 115 kB RS232 interface to PC serial port
> > 32 bit position resolution
> > 3 step and direction axes
> > 16 digital IO lines (8 in, 8 out)
> > 2 analog inputs, 2 PWM outputs
> >
> > Not a bad little device. One drawback is that it expects a
full
> > serial packet every 6 mS, so the the PC is still more or less in
> the
> > timing loop during motion.
> >
> > A major positive is that it's PIC driven, and the hex image of
> the
> > chip's program can be downloaded and programmed by anyone - no
> > exclusivity over the hardware.
> >
> > Like I said, an option to drive this unit thru TurboCNC is still
> in
> > the pipeline. Looks like there a good oppurtunity for a Windows
> > programmer to step to the plate here and offer something for that
> OS
> > as well...
> >
> > Dave Kowalczyk
> > Everett WA
> > TurboCNC control software -->http://www.dakeng.com
> >