Re: Black Box Question

Mariss,

So the b-box lives next to the machine, at the far end of a serial
cable, right?
And it may be IN an enclosure by itself, OR it may be "included" in a
larger box which incorporates drives?

If these assumptions are correct:

Give me an onboard dc jack, but back it up with a 2pin header. Put
the jack where it "makes sense"(so I can acces it with a simple hole
in the enclosure, considering the independant b-box enclosure (w/o
drives).

Now it gets tougher: It is very different matter to connect to the
drives inside a big enclosure, than to "feed" an ALREADY enclosed
drive box.

Is the db25 intended to be part of the "motherboard"(MB) of your
device? Can the "daughter" board connection (to the mother) include
the signals to "feed" the MB mounted db25? Just let the MB design
handle the routing of each daughters output through the MB-daughter
connectors to specific pins on the output DB25, depending on position
in the MB "slots". If not, wiring a bunch of 10p connectors to one
db25 (mounted on the enclosure wall) will be a PITA, IMO.

However, If you put the 10p idc pins on each daughter ALSO, you make
it easier for the "all-in-one-box-with-drivers" guy. He just ignores
the db25 on the MB. Using some short 10p-idc ribbon to the screw
terms. of the individual drives is easy...

There are already quite a few 3 axis bds and other systems including
4 axes set up for db25 connection, but they don't share pinouts
exactly.

If the output connector of your device is a db25; A dual inline 18P
header just inboard would make it possible to use straight jumper
blocks if the "default" pinout was acceptable; while allowing the use
of a configured plug to accomodate non-std. pinouts. (one 18p row is
isolated from the other row. You can jumper straight across, or wire
a plug which connects the "in" pins to the "out" pins, as required)

Currently, I use 232 jumper boxes this way at one end of a 25p cable
to switch the signals around when using different s/w pinouts. Each
is labeled as to "who" it goes with.

I wouldn't use the db9. You don't gain much of anything over the 10p-
idc's. db9 m-f cables are not a common item? and the DaughterBoards
would be easier cheaper to mfr. with the 10p-idc, I'd think (and cost
less too).

Hope this helps.

Ballendo

P.S. What "flavor" of gcode are you planning to use? I think you will
be better off implementing "canonical" commands (as the term is used
by EMC) as input to your system. This allows the PC software more
latitude in choosing flavor and implementation of g-code. In fact,
allows the s/w to not use gcode at all, if desired! More importantly,
it gets us out of the "need an upgrade to the gcode routines in the
box please, Mariss" situation that is nearly as bad as closed
systems...

P.P.S. I would want the "default" pinout of the output db25 thus:

2=xstp,3=xdir,4=ystp,5=ydir,6=zstp,7=zdir,8=auxstp,9=auxdir (ideally,
in a 3-axis system, pin 8 and 9 could be additional outputs)

10=Estop, 11=x home, 12=yhome, 13=zhome, 15=auxhome (These homes
could also be used for limits if the s/w was set up for it. Pin 15
becomes additional INPUT in a 3 axis system.

1,14,16,17= general I/0. Can be used for idle, drive enable, coolant
(s), probe input-i'd use pin 1 for this, spindle encoder inputs;a,b
index, etc.

18-25=gnd

Where will optos be, if any?

--- In CAD_CAM_EDM_DRO@y..., "mariss92705" <mariss92705@y...> wrote:
> Bill,
>
>Good evening! Maybe I should explain. I am looking at having an 8-
>bit microcompter (Rabbit Semiconductor RCM2300) accept the linear
>and circular interpolation G-Codes over an RS-232 port and control 1
>to 6 axis hardware pulse generator cards. Only as many cards as
>needed would be plugged in. The options are:
>
> (1) Have a common (DB-25?) step/direction connector for all cards.
> (2) Have a step/direction connector on each plug-able card.
>
> If (2), what kind of connector:
>
> (1) DB-9.
> (2) IDC 10 conductor ribbon cable.
>
> I'm just trying to get some idea how people would like to have it
> before I finish the board layout.
>
> Mariss
>