Re: PPMC, etc.

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

Dave what advantages has the PPMC over the other
available PC bus multifunction cards?  Is there any
speed reductions from sending a special command 
language over the parralell bus, as opposed to the
PC bus? Finally what is the cost of the motherboard,
dac card, encoder card and cables?

Thanks, Steve

----------
> From: dave engvall <dengvall-at-elltel.net>
> To: Multiple recipients of list <emc-at-nist.gov>
> Subject: PPMC, etc. 
> Date: Friday, April 20, 2001 12:49 PM
> 
> 
> Hi all,
> After a month plus of frustration I have a ppmc
> interface up and running on a real machine.
> 
> First of all let me talk about the machine, then
> I'll go on to comments about the interface, etc.
> 
> Machine: Cincinnati 'contourmaster' tracer with
> all the tracer stuff removed. Ballscrews on x and
> y and for the purposes of this discussion z is
> really w driven by an acme thread (knee).
> Servo motors are an SEM  MT30H4  4:1 belt drive on
> x, Pearless (about like the MT30 ) on y and a
> small gearhead on w. Acu-rite 0.0002" glass scales
> are used on all axis.
> Servo drives are Servo Dynamics 1525-BR on x and y
> and a GE HiAK (1980 vintage) drive is used on w.
> 
> Processor is a P200 ( from Boeing), interface is a
> ppmc motherboard, encoder board and dac board from
> Jon Elson/Matt Shaver. When received the boards
> refused to work with my machine (Dell) or with a
> P166 board I bought locally (cheap). I sent the
> cards to Matt Shaver where they worked just fine.
> To make a long story short the parallel interface
> is critical. Matt shipped me a $20 IEEE-1284
> compatible ISA parallel port which works just fine
> in the P200 machine. At  first the ppmc was not
> initializing correctly and Jon e-mailed me a
> patched ppmc_encoder.c which I copied into the
> source tree and recompiled. This patch provided
> for more wait time upon initialization and fixed
> the problem.  I'm running RH 5.2, 09J patch and
> Mar 2000 emc code and xemc.
> 
> Paul has included the initial ppmc code in the
> BDI. Jon's mod to ppmc_encoder.c was too late to
> make it but should be easy to incorporate after
> the initial install.  Paul, of course, had nothing
> to test against so maybe at NAMES all the correct
> resources will converge. :-)
> 
> Recommendations:
> 
> 1. if you have problems with ppmc board set being
> recognized: (a). try a different parallel board.
> The one Matt sent me is: SIIG, Inc. Mod IO1818.
> 
> 2. make certain you parallel port cable is
> IEEE-1284 qualified. Keep it as short as
> possible.  I'm using a 6'.
> BTW  it takes a 25 pin to 25 pin not 25 pin to
> Centronics.
> 
> 3. Strain relief is nice on all cables into the
> ppmc.
> 
> 4. You probably want some kind of a card cage. I
> made my own from aluminum stock and delrin (for
> the card guides).  Some day we will get a pic up
> on a web site but both Matt and I have the pics.
> 
> 5. get the modified ppmc_encoder.c from Jon, Matt
> or me and install it.
> 
> My thanks to Jon, Matt, etc. for taking on the
> project of providing an alternative to the stg
> card.
> 
> Dave
> 
> 
> 
>