Re: [CAD_CAM_EDM_DRO] Interface options, headless boxen, and remote control ...

Bryan-TheBS-Smith wrote:

> Again, I don't think you even need an LCD display on the Linux EMC
> box itself. At most, maybe a "kill switch" on the Linux EMC box,
> but everything else is controlled on a remote display in the other
> room. All you need is Ethernet to your Linux EMC box -- and that's
> it! And no "special software" is required on the workstation, only
> the 150KB "vncviewer.exe" program.

Okay, I guess what I'm saying is that you don't need a full-up
monitor/KB/mouse on the Linux EMC box. Everything can be done
remotely. Now if you still want to have a "basic interface" on the
Linux EMC box, there are several ways we can approach this.

The most simple setup I can think of is by using a numerical keypad
(PS/2 or USB, only $25-30), and a serial terminal on the unit.
Although the Linux box will still boot a full GUI session for remote
display, there would also be a log and/or basic menu screen at the
box itself. The menu would use numerical hotkeys, and the keypad
would also allow you to modify numerical values.

The terminal itself could be an old VT100-type that connects to the
serial port (Linux doesn't care what the "console port" is, be it
VGA, serial terminal, MDA, etc...) -- should be able to find a used
one for <$100 (check to see if your company would sell you one from
storage ;-). You could also get an old monochrome MDA video card
and monitor for <$100. Another option is to just put a cheap VGA
card and get a monichrome VGA monitor, which could be had for <$100
as well (which is my setup in my "server room" at home).

The "menu" software is cake to write (*NO* prior software
programming required). The "dialog" program that comes with RedHat
distros is for building simple programs/shell scripts for I/O. You
can use it to take input, watch log files, etc... Examples of a
dialog script in action can be found here (which is a small little
sysadmin program I wrote):
http://smithconcepts.com/files/conmenu/conmenu_kernel.jpg
http://smithconcepts.com/files/conmenu/conmenu_messages.jpg

So in addition to having a VNC session startup at boot for remote
display of the Linux GUI, we also setup the main console to point to
the local terminal/monitor, using the keybpad for local entry.
Remember, on UNIX/Linux, a _true_ multiuser OS that can have
multiple users running multiple sessions to multiple displays, you
can use both the keypad-terminal interface at the unit, and the
full-up Linux GUI remotely via VNC on another system.

So, to revisit my "ASCII Art" of a setup:


Linux <Ethernet> Remote
Term/Pad -- EMCSys ============ PC Wks -- Mon/KB/Mouse
||
<RS-422> ||
<IEEE 1284> ||
||
CNC
Components

-- TheBS

--
Bryan "TheBS" Smith mailto:b.j.smith@... chat:thebs413
Engineer Absolute Value Systems, Inc. http://www.linux-wlan.org
President SmithConcepts, Inc. http://www.SmithConcepts.com