Re: [CAD_CAM_EDM_DRO] Re: Pico VS IMService???

turbulatordude wrote:

>>the USC board was delivering 45,000 steps/second per axis. This,
>>
>>
> of course, is not the limit, it can go to about 300,000 steps/second.
>
>
>That is impressive
>
>
>

Well, this is what you can do in dedicated hardware, and Field Programmable
Gata Arrays make custom hardware very affordable.

>
>
>>It allows you to connect encoders from the motors to the board,
>>
>>
> which then relays the position information back to the CNC computer.
> One of the greatest advantages of this is that you can switch back
> and forth between CNC and manual operation, and use the computer as a
> DRO when in manual.
>
>
>Another great feature, I assume the computer required encoders and
>does not 'see' the steps as the DRO ?
>
>
>

Well, if you are using Gecko or Rutex servo drives, you already need
encoders
for that.

I'm not sure what you mean by "not 'see' the steps as the DRO".

>
>
>
>>The USC board also has 14 opto-isolated inputs for limit and home
>>
>>
> switches, so you can have separate indications of - and + limits for
> each axis.
>
>The site
>
>http://pico-systems.com/univstep.html
>
>that shows the board, lists one parallel port. is that all that
>connects the PC to the board ? it seems like you have found a way to
>exceed the normal 5 inputs of a simple breakout board.
>
>
>

Yes, it only requires one parallel port. The parallel port does not
have dedicated
pins, as it does for the traditional step/direction output. It becomes
a communications
channel between the computer and a peripheral device, so registers are
addressed,
read out and written to, to accomplish the functions needed. With EMC, the
way we are running it now, 1000 times a second the position is read in,
a new
velocity computed for each axis, and the new velocity is sent to the rate
generators. Also, the sense switches are read in, and solid state relay
outputs
are sent out at the same time.

The IEEE-1284 protocol makes it possible to access 256 registers on devices
on the (parallel port) bus, and so it can support up to FOUR of these boards
on one parallel port!

Jon