Re: Single Servo circuit / computer&touch panel combo

["Steve Carlisle" <quatsein-at-island.net>]

There are literly dozens of flat panel/PC based MMI manufacturers
out there. The low end products start at around $2500. Wish I had
that kind of money to through at a MMI.

Steve

----------
> From: Doug Fortune <pentam-at-home.com>
> To: Multiple recipients of list <emc-at-nist.gov>
> Subject: Re: Single Servo circuit / computer&touch panel combo
> Date: Saturday, October 21, 2000 11:27 PM
> 
> 
> Jon Elson wrote:
> 
> > > >From what I have read on CAD_CAM_EDM_DRO list, Jon Elson
> > > is very close to having this done.
> >
> > Yes, the hardware IS done!  I'm just waiting for the PC boards to come
> > back from the fabricator.  I also need to design a motherboard for the
> > individual boards to plug into and get that made.
> 
> Good work Jon!
> 
> > Now, this only goes from encoders to a +/- 10 V servo velocity command.
> > I think what the originator of this thread was interested in was a
> > complete digital PWM servo drive, which would get rid of all that nasty
analog
> > circuitry.  I'm not sure that is practical at low cost.  You will need
> > to have an ADC reading motor current at a pretty high rate, and
something
> > to do servo loop calculations and set the desired pulse width.
> > I do this 100,000 times a second (in other words, on every pulse).
> > It obviously isn't practical to have the main CPU handle it at this
rate.
> 
> <Jon, see the reference to an embedded PWM in the computer below>
> 
> I'd like to mention I've been looking for a combination industrial
> color touch sensitive screen and IBM PC motherboard, obviously to
> use EMC as a replacement for an original toasted CNC controller.
> 
> I have come across a really REALLY nice unit at:
> http://www.zflinux.com/netdisplay.html
> 
> which has a host of features to drool over:
> 
> The ZF netDisplay  5MX OEM Flat-Panel Computer is a complete,
> ready-to-run, 180MHz Pentium-class PC  (also a 486/100 version)
> with a color LCD and touch-screen in a compact form factor,
> ideal for a wide range of OEM applications. The netDisplay
> offers 100% desktop computer functionality in a rugged,  easily
> integrated package just over 2 inches deep and weighing only 2 pounds.
> 
> The ZF netDisplay is available with a 12.1" or 15.1"  active matrix
> color LCD. A high reliability, advanced technology 4K x 4K matrix
> touchscreen is included.
> 
> The netDisplay boots into DOS straight out of the box.   The net-Display
> is certified to run many other popular operating systems including
> Linux,  Microsoft® Windows® 3.1, 9x, NT, CE, Phar Lap's TNT
> Embedded ToolSuite®,  Microware OS-9, and Sun Embedded Java.
> Specifically, there is a Linux development kit!
> 
> It has 6 serial ports (one can be RS485),  1 parallel port,  2 USB ports,
> 10/100 ethernet, PCI or PC104 expansion slots, a CompactFlash socket,
> IDE/floppy, KB, and soundblaster (for that all-important
drown-out-the-noisy-machine  rock
> music).
> 
> It also has an additional 12 TTL I/O bits which will be very handy.
> 
> I know this sounds expensive, but they claim "When your design calls
> for a flat-panel PC, turn to netDisplay, the industry's fastest, most
> cost-effective  path to embedded touch-screen computing."
> 
>  - - -
> 
> It is interesting that Jon mentions the need for PWM, and that if the
> above computer is based on the MachZ (their base chip) then it would
> seem to include (at least one)  onboard programmable 100 Khz PWM.
> http://www.zflinux.com/machz_specs.html
> 
> Maybe it might not be programmable fast enough for motion servo
> motors, but it might be good enough to use to control the spindle
> motor (for constant surface speed machining in a cnc Lathe application).
> 
> At the current time, it looks like I will like to try Mariss' Geckodrive
G340
> modules (parallel port step and direction to DC servo)
http://www.geckodrive.com
> for the X, Z, and turret motors,  but I have to find a solution to drive
> the big 30 HP  spindle motor (ie a single one of Jon's drivers), and just
> maybe the embedded PWM is good enough for that (ie maintaining an
> exact constant speed for threading, and varying the spindle speed for
> CSS machining).  Hope this explanation makes sense!
> 
> Doug Fortune
> 
>