See the News Flash at the bottom
What are all the connections on this drive? Do I need to use them all?
This is actually a very simple drive to connect with many things that you
don't need to contend with if all you want is standard step and direction functionality.
The absolute minimum you need to connect is Step, CW/CCW ( Gecko Dir), and Opto in (Gecko
+5V) for the logic and A+, A-, B+, B- for the motors. On the motor side
A
Com and B Com are there just to give you a place to put the center taps on 6 wire motors and don't do anything on an electrical basis.
You can just as well tap the center tap wire at the motor (insulating it so it
does not short on anything). The motor Gnd is for a case and wire shield ground point if you use them and everything works fine if you don't.
Additional connections for additional features
All the additional features work by pulling it low (connecting to ground) to activate the option. When they are not connected to anything or pulled high (+5v) you will get the default state.
HI/LOPWR - Default is HI (Hi power). This is a way that you can manually control whether current reduction is
occurring. The way I would use it would be to disable auto idle current reduction and then use a pin from the computer to connect to HI/LOPWR. When the pin toggles the drive change from
the full power as set by the dip switches to 50% of the set power.
ENA/NOPWR - Default is ENA (Enabled). This allow you to let the motor freewheel without having to power down the drive when it is in NOPWR mode. As soon as you let the line go high the drive instantly energizes the motor.
RUN/RESET - Default it RUN. This causes the drive to let the motor freewheel like NOPWR, but also causes the microprocessor in the drive to reset. When you let the line go high the microprocessor starts it's boot sequence and it takes a few moments for the drive to come up.
The remaining 2 pins in the logic section are FAULT and OUT COM. They are used together
to connect a device that will alert of a drive fault. From what I can gather it is an open collector arrangement.
A fault condition is triggered by the following:
Temperature - internal air temp exceeds 140 degree F
Under voltage - DC voltage drops below 22VDC
Overcurrent - from short circuit-phase to phase, phase to ground.
What do I connect the OPTO IN to and do I connect to a ground on the computer?
Like other opto protected drives the CMD-260 uses a +5V connection to the computer as the common and not ground. This seems crazy to people, but makes perfect sense from an electrical perspective. There is no connection to a ground source on the computer. The only connection to the computer is the step, CW/CCW (dir), and OPTO IN which goes to a +5V source from the computer.
On my computer +5V (OPTO IN) is just connect to a spare drive connector in the computer through a wire I bring out the back. The +5V wire on a drive connector is the red wire, but check with a meter to be sure. You can also get a +5V source from your computer through a game port (DB15) or a PS2 port.
News Flash
From Art Fenerty
Creator of Master5 and Mach1 CNC controller ( ArtSoft CNC Software Company
)
After testing, it became evident they were using a very sensitive Opto coupler. By adding a 1K resistor to the input, they became very smooth and accurate. Both the step and direction lines needed the resistor. Otherwise they were inaccurate in one direction only. With the resistors, they are nice controllers and seem like they will do nicely.