i may be confused here but the encoder only puts 3.5 volts on A or any other phase when its made any other time the phases are at 0 volts so wouldnt the relay only come on when a phase is made and thus showing motion? so when A is made 3.5 volts would trigger a relay and send 24voltbpower to bei card which sees 24 volt input and outputs 5 volts to the plc to be read as A+ on then go off when A goes to 0v B phase would go to 3.5 volts and trigger another relay and then drop to 0v and so on