Design And Implementation Of Serial Server Based On W5500 And STM32

Serial server is an equipment which can mutually transfer serial signal and network signal.In the hardware of serial server,it transfers serial port data into online data,and transmits online data to serial server management software in the remote host,and further transfers online data into virtual serial port data.Nowadays,traditional equipments mainly adopt serial communication,and now it can’t satisfy the requirements of long-distance transmission and the rapid networking.Thus the serial server is mainly adopted in automation of serial equipment.This thesis designs a serial server adopted in smart grid acquisition in communities,which has three main functions:(1)it comes up with a hardware design scheme combining with STM32F103RCT6 microcontroller and W5500 network chip.It designs a microprocessor-based circuit,lattice circuit,serial communication circuit,Anti-reverse circuit and power regulator circuit.According to schematic circuit diagram and placement and routing,the author designs PCB Circuit board.(2)it designs a serial server firmware,and put forwards a way of adopting random noise signal collected by AD as random seeds.And through tests,this way is available.This is used to encrypt communication in network design.It designs a digital protocol which transfers serial port and network data,and it realizes functions of serial server’s hardware.(3)It put forwards three-level data transmission models: serial port server management software,serial port management driver and virtual serial port.It designs serial port management software,serial port management driver and USB Virtual Com Driver.By predicting the arrival time of data,it can assure the time of sending heartbeat packets and achieve realizing sending fewer heartbeat packets to avoid the effects of anti fake-animation.Eventually,through actual on-line testing,it shows the serial server designed by the thesis can satisfy requirements of the projects.