Showing junk data in RS485 Protocol using pic24f?
This is the most common method of interconnecting RS485 devices: -



Note two important things: -


0V is common to all slaves and master
End-of-wire termination resistors (LT) are used


Here's another example: -



And another here that tries to avoid earth fault currents in an installation: -



This one is quite pretty too: -



Note that the black circles around the red and green pair imply a screened cable that is earthed.