rs485 cct
I've used a isolated link dc-dc converter for the +5v.
I've also used opto 6n137. protection using P6KE6.8 TVS diodes.
So the question is... for this isolated link, should I earth all terminals with a 3rd wire, or earth each with 100R resistor with a common 3rd wire or
should I join all terminals ground together with a 3rd wire.(no connection to earth) ? Its a mouthful ...I know.
Using only 2 wires, my 485 are damaged quite frequently esp. outdoor sites ,though there's no sign of lightning damage...system offline...sustained customer abuse... help..
thanks.