Re: [CAD_CAM_EDM_DRO] Re: Smart/Dumb box again...

Alan Marconett KM6VV wrote:

> So Jon,
>
> How about some chips! I'm ready for some to play with! PLCC? Probably
> need a board fab'ed to hold it too. I take it that it is ISA or PCI?

The part I used (because I was also using it in the encoder counter) is the
XCS10-3PC84. That's an 84-lead PLCC. I use a $1.00 socket for the
chip rather than solder it down directly. The program is held in static ram,
so it needs to download from a serial prom every time power comes up.
I was only able to get 2 channels of the rate generator into the XCS10 size
chip.

The boards connect to the parallel port, and use IEEE-1284 hardware signalling
to communicate between the CPU and the boards. This allows up to 256 different
registers to be addressed. I set it up to have each board accomodate a block
of 16 addresses, which works out real well. I already have 15 of each of these
boards made. To use the rate generator, you need to have an encoder counter
to keep a position count. You can either count step pulses or count a physical
encoder on the motor.

I can sell you a 4-axis encoder counter board for US $200, and the 2-axis
rate generator for $200 also. The motherboard is $100. I was hoping to be
able to make a 4-axis version of the rate generator that would use the same
board as the encoder, to cut costs, but it didn't work out, as the XCS10 only
has enough internal logic for 2 axes. I could reduce the timing resolution (clock
speed) and the # of counter bits, and see if I can get at least 3 axes to fit into
the XCS10 chip. I plan on making a board with everything on one chip,
including digital I/O. But, that is a few months off. I also intend to make
a separate digital I/O board to go with the separate encoder and DAC boards
for servo use. That will have 16 inputs and 8 SSR outputs right on the board.

This all works with EMC, by the way. I only have the rate generator hooked
up to one motor on the bench, right now.

Jon