RE: [CAD_CAM_EDM_DRO] Geckodrive asking for user input

Hi Mariss,

Obviously I'm not a big commercial user, but I'd prefer #1 if I had to
replace a driver (G210) in one of my driver/PS boxes. Otherwise, I'd have
to REWIRE part of the box! And having just PART of the circuitry different
could lead to problems later.

#2 sounds great for my new design, however.

Alan KM6VV

>
> Hi,
>
> I'm cross-posting this everywhere because I need a lot of replies
> fast.
>
> I'm nearly done with a G201/G210/G202/G212 replacement design called
> the G203 for right now. It is a complete, clean-sheet CPLD based new
> circuit. Same size and pinout as the G201 drive but a whole lot of
> new features.
>
> Here's where I need input. The G203 uses 3.3V logic which makes the
> step/direction opto-solator interface require much lower current. The
> quandry:
>
> 1) Be 100% backwards compatible with the existing drives. That means
> supplying +5VDC to the COMMON terminal and require 5VDC
> step/direction signal levels. The G203 would keep an unplug and
> replace compatibility with our current drives.
>
> 2) Change the COMMON terminal spec from +5VDC to GND. The G203
> requires only 2mA max to operate step/direction optos instead of
> 16mA. The G203 has a max step pulse frequency of 350kHz (>10,000 RPM
> on a 1.8-degree motor) without any funny G201 step/direction timing
> restrictions.
>
> The result is supply step, direction and PC ground to the G203 and it
> will run. It will work now with 3.3V or 5V logic; no level-shifting
> breakout boards are required, no +5VDC supplies.
>
> Please let me know: Option (1) or option (2). The first 1,000 boards
> must go to the PCB fabrification house Monday.
>
>
> Mariss
>