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-isolator interface work with 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