Re: question for Mariss

2 points:

1) While "common" may mean "ground" to electricians, in electronic
lexicon "common" has the broader definition of "shared". For
instance, it is perfectly valid to say "The Vcc pin of the IC goes to
the common +5VDC bus" or "The comparators use a common reference
voltage".

The nomenclature used with the G210/G340 drives becomes problematic
because they can be configured as either "common GND" or "common
+5VDC" via the input option header. I opted to simply call the
terminal "common" and extended that name to all the drives in the
interests of universallity.

This may all become moot with the G201P. I'm exploring the use of a
Shottky diode full bridge across the STEP and DIRECTION opto LEDs.
The it won't matter if the "common" is connected to GND or +5VDC.


2) There is no need or provision for grounding the +5VDC back to the
drive. Current flows from your PC +5VDC thru the opto LED, back thru
your STEP or DIRECTION line into your parallel port pin which then
shorts it to GND inside the PC to effect a step or direction change.

Assume you have a +5VDC battery and a switch connected to the battery
GND. Assume both are in a box and 2 wires come out of this box. One
goes to the battery +5VDC and the other goes to the free end of the
switch. You attach a 5V light bulb to these wires. The bulb turns on
and off when you operate the switch yet neither wire is GND.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Monte Westlund"
<montejw@e...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Hans Wedemeyer <xyz@h...>
> wrote:
> > When Mariss requested people to request/suggest changes, I
> explained that "Common" is synonymous with Ground NOT +5VDC.
> > I am using the G201 and it has the same confusing marking, on the
> G201 Common means +5VDC . If you check the data sheet
> > (dated:Feb/8/2001) you will see the the drawing uses +5VDC for

the

> terminal marked Common on the device itself.
> > I suspect the G320 has the same mistake, best make sure and wait
> for a reply from someone that is using the G320 or Mariss.
>
> I just built a Camtronics controller using Gecko 320 servodrives.

The

> Common terminal is powered by +5vdc from the PC from an unused

power

> supply connector for a harddrive, floppy, etc.
>
> Another fellow built a Camtronics controller and had a 5vdc power
> supply built into his controller.
> http://www.homecnc.info
> I don't know where/how he grounded the servodrives to his 5vdc

power

> supply, or if he needed to. I assume that you would, but I'm not an
> electrical eng. So there must be a way to make it work with an
> external 5vdc power supply, I just don't know how it's grounded.
>
> Monte