Design and Application of Custom RS485 Communication Protocol

As RS485 network has the character of simple construction, lower cost and easy extension, it has been widely applied to many application systems based on Radio Frequency Identification (RFID). In RS485 network the mainframe can access many readers. Aiming at the demand of a RFID application system in which the mainframe needs transmitting information to display terminal, this paper proposes a solution. Through connecting display terminal and readers into RS485 network, defining custom communication protocols between the mainframe and display terminal, the mainframe can access display terminal like the other readers. The implementation results show that the solution has achieved the anticipated target and run stablely and reliably.