Thanks all for clarifying the cables so far, I’ve re-soldered the XLRs to keep pin 1 separate from the chassis. Had a quick look and am able to separate the mains earth and DMX ground quite easily in the units. Also
I'm paranoid it’s going to happen again, would optical isolators help to reduce this and would I need one on the input and output of each unit or is that overkill. Also do you think it’ll be enough to keep the grounds and earths separate.
Apologies, just to explain a little more, this is a setup over Xmas that I’ve been volunteered for for a local non profit organisation. I’m an electrician but when it comes to DMX I’m a plug and play kind of person with a basic understanding until it goes pop, and would like a set up we can just roll out and plug in every year.
thanks again, really appreciate all the help