Comm Error Solved.

[rebajm]

Trying to find the cause of the dreaded occasional “Comm. Error” and after reading that for some, the problem stopped when they used a laptop, an idea came to mind. A laptop is not grounded through its power supply like desktop computers are, therefore no ground loop. I dug up an old 3 to 2 prong grounding adaptor that sat in the junk drawer for years and attached a length of 12 gauge THHN wire between the ground lug on the adaptor and aluminum control box on my PRT Alpha. (Do not rely on the USB cable solely to provide the ground connection between the control box and computer.) I plugged my computers power strip into the adaptor and then the adaptor into the outlet. (Anything else connected to the computer like the monitor or printer must be plugged into the same power strip to be also isolated from the outlets ground.) I’ve not had a single problem since providing this system ground method.

[myxpykalix]

YAAAA!!:rolleyes: lol

I use a laptop and have not had any issues. I recall when i first started i was getting errors and determined it was from static electricity because my dust collection was not grounded. Since i fixed that i have had no errors in years. Is your DC grounded?

it feels good when you finally solve a problem that has been biting you in the butt:eek:

[rebajm]

That was my point, those that went to using laptops were not having a problem afterwards. I made sure all dust collection was well grounded, but still the same problem. Look a it this way, your ShopBot and other toys may be hooked up to a sub-panel in your shop, but yet you plugged your computer into an existing wall outlet that's feed from your main panel. How many feet of ground wire are now between your computer and control box? And how long is your USB cable? That, I'm sure is a large ground loop, which can cause all kinds of induced interference into the connections of that small USB cable. A direct ground connection between the computer and control box, and by eliminating the outlet ground, fixed it for me.

[dana_swift]

John- glad you solved your problem. Most folks dont have any idea what a ground loop is, or how to avoid them.

There is a belief the the solution to everything is to ADD ground wires, not remove them. Congratulations on the insight and solution!

Looking forward to your future contributions to the forum!

D

[rebajm]

Thanks Dana. I must say that projects are much more enjoyable when you don’t have to worry about the machine shutting down.