Re: [CAD_CAM_EDM_DRO] USB of Jon Elson

alex wrote:

>Sorry,
>I meant USC!
>Alex
>
>

OK, then this part of my response is still applicable.

>>Are you referring to my "Universal Stepper Controller" (USC). Right now,
>>there are only drivers for EMC. As this unit simulates a closed-loop servo
>>system (or can be used for real closed loop operation with encoders) it
>>needs
>>software designed from the ground up for servo operation. If TCNC
>>can handle devices like this, where you read current position and then
>>compute
>>how fast to go to get to the next point at the right time, then a driver
>>should
>>be possible for it. If the software generates step pulses from deep in its
>>bowels, like Mach 2, then it is not likely.
>>
>>
>>

But, let me expand just a little.

The interface specs of both my PPMC and my USC boards are posted in
detail on
my web pages, and I would be glad to assist anyone in trying to whip up
a driver
for these units. I already looked into making a driver for Mach 2, and
found that
generating step pulses through CPU timing loops and interrupts was so deeply
ingrained into the entire low-level section of Mach 2 that it was very
impractical.
But, for any software that had a clear breaking point between the
higher-level
trajectory planning and the lower level step pulse generation it should
be possible
to adapt it to these boards. The basic method is the CPU reads the
current position,
compares to the desired position at that instant, computes a new
velocity to minimize
error, and sends that velocity to the DAC or step rate generator.

Jon