Working with RS485

[dhouston]

• http://en.wikipedia.org/wiki/Ground_loop_(electricity)
  http://www.epanorama.net/documents/groundloop/
  http://www.trinitysoundcompany.com/grounding.html
  http://zone.ni.com/devzone/cda/tut/p/id/3394

• http://en.wikipedia.org/wiki/DMX512-A

[The Master]

Ive read all of those documents. I understand the one about DMX but the ones about ground loops are a bit confusing. From what i can see i shouldnt have a problem because all devices are isolated from the mains using a transformer for power and opto isolators for the triacs. There are earth wires going inside the lights but they dont connect to anything since the lights are made of wood. Each light has IEC in and out sockets so all of the lights could be run from a single socket. In practice i will probably have them in 2 groups (left and right) but no matter how many groups i have they will all plug into an extension so they will all run from just one wall socket.

I wouldnt have thought i would have any problems because of all the low voltage stuff being completely isolated from the mains and the short cable distance but i have noticed problems with my speakers before. If i connect a laptop to my mixer at the same time as my speakers i get very loud buzzing until i press the ground lift button on both speakers. That happens with the laptop, mixer and speakers all plugged into the same extension