Re: Smart/Dumb box again...

Hi Jon,

thanks for the additional info on your boards.

So it will cost about $700 to get 3 or 4 axis support? I like the ECP
(IEEE-1284) interface! Sounds like great resolution, although if one
just wants to run "open loop", then is the encoder board still
necessary? Looks more like you're targeting commercial systems, I was
hoping to get in under $200 ($100?) for a 3 or 4 axis rate generator.

84-lead PLCC's are not something I want to solder in, either!

Alan KM6VV


Jon Elson wrote:

>
> 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