Acorn to G203v Pullup Resistor

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legacytorch
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Acorn to G203v Pullup Resistor

Post by legacytorch »

I plan to run my new Acorn CNC control with Gecko G203V drivers. I see that according to drawing S14842 from the website this configuration requires the use of an external 5vdc power supply and 220 ohm resistors. Scott form Centroid tech support explained that the resistors are needed to insure a clean output signal.

I think I understand what it is doing, but I am still not clear about how to wire it up. Do I need to isolate the different axes? I probably just don't understand the theory but in my head there should be signal crossover with the way it is wired in the diagram.

Also, what wattage of resistor is required? I have some 1/4w ones, are they large enough?

Just hesitant to release any magic white smoke!

Thanks
762x51
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Re: Acorn to G203v Pullup Resistor

Post by 762x51 »

You would want to wire up each axis as shown on the drawing.

A lot of us use the Meanwell RD-35B to power the Acorn and supply the +5 VDC for the stepper or servo drivers. You can get them from Jameco for $11.95 + shipping.
tblough
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Re: Acorn to G203v Pullup Resistor

Post by tblough »

1/4W resistors are fine for pull-ups. These maintain 5V on the data lines until a device pulls them down to ground. There is very little current involved.
Cheers,

Tom
Confidence is the feeling you have before you fully understand the situation.
I have CDO. It's like OCD, but the letters are where they should be.
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Re: Acorn to G203v Pullup Resistor

Post by diycncscott »

FWIW (Assuming no internal pull ups)

5VDC = 470 ohm
12VDC = 1.1K ohm
24VDC = 2.2K ohm

All = ~10ma

5VDC = ~.05W
12VDC = ~.13W
24VDC = ~.26W
legacytorch
Posts: 42
Joined: Fri Dec 29, 2017 2:39 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 985DAD489A3F-1215170079
DC3IOB: No
CNC11: No
CPU10 or CPU7: No

Re: Acorn to G203v Pullup Resistor

Post by legacytorch »

The drawing only shows the one axis. I have modified it to include the other two as I assume it needs to be.
Acorn_G203V mod.jpg
I know that this is simple, but I really don't feel like cooking something.
762x51
Posts: 119
Joined: Wed Aug 02, 2017 8:40 pm
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: B0D5CC56DD75-0605170063 , 985DAD4295CF-0928170127 , 38D2694E4703-1222170401
DC3IOB: No
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Location: Near Guilford College, Greensboro, NC
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Re: Acorn to G203v Pullup Resistor

Post by 762x51 »

legacytorch wrote: Fri Dec 29, 2017 10:32 pm The drawing only shows the one axis. I have modified it to include the other two as I assume it needs to be.


I know that this is simple, but I really don't feel like cooking something.
You have it right - Nice job of modifying the drawing
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