Re: porting new D/A boards to EMC

[Ray Henry <rehenry-at-up.net>]

At 01:42 AM 5/3/2000 -0400, Doug wrote:
<snipped>
>In my latest round of brainstorming how to get servo's going on the cheap,
>I had an idea as I came across:
>
>http://www.bsof.com/d140prod.htm
    $99  8  bit 8 channel A/D, 24 bit I/O ISA card
>http://www.bsof.com/accsprod.htm
    $20  DB-37 pin breakout board to connect to the above.
    $15  DB-25 pin breakout board for the parallel port
>
>As you can see it has eight DAC channels at 8 bits per channel (6 usec
settling
>time  ie 166.6 KHz), and hence expandability up to 8 axes.    As each axis
of a
>homebrew  brushless motor driver circuit would have its own 20 bit up/down
>counter for positional tracking,  I would use some of the bits (perferably
20,
>otherwise 16)  of the 24 bit I/O to feed positional information back to
EMC for a
>closed loop.  Three of the remaining bits would be output as a 1-of-8
decoder to
>nab the positional counter data of the desired axis.
>
>I'd still use the parallel port,  for the Limit/spindle/coolant etc
switches and relays.

An under 200.00 dollar solution for brushless motor signals sounds real
attractive to me.  I don't understand it all though.

Ray