I am developing a solution for Powerline communication. Study different Circuits, I stuck when I send a signal from USB to rs485 Converter to my module it is not read any data on the slave side . when I check with MSO I find out that signal Transmitted, but the Differential signal was less them 200 millivolts. Then I study that I need an AC / DC square wave signal for communication when I send it through DC line the RS485 chip not read this differential signal.
So according to my investigation, I find either I have to generate a square wave power supply for communication over DC power.
Reference Design from :
**Using SN65HVD96 to Create a Power-Over-Data and Polarity Immunity Solution