Re: [CAD_CAM_EDM_DRO] Re: question for Mariss

Mariss,
Correct about needing to qualify the term, as I just replied to Tim's post... COMMON in this case SHOULD BE Qualified with something else.
Common alone "implies" chassis or ground.

Even electricians should use the term Common and qualify it with Neutral etc.

The confusing thing is the data sheet shows the connection as +5V for that same terminal and the silk screen uses
the word Common, had the data sheet Explained the meaning intended for Common, perhaps I would not have been as confused.
I can see where space is an issue on the screen screen, but is hardly an issue when it come to a PDF file.

Best Regards
Hans W

Mariss Freimanis wrote:

> 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
>
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