Design of preverifying Serial-Ethernet communication gateway based on LM3S8962

To connect different RS485 networks and transmit data on Ethernet without changing the current network structures and configurations, a preverifying Serial-Ethernet communication gateway is designed based on an ARM Cortex-M3 architecture microcontroller LM3S8962. It transfers the data through its integrated Ethernet controller, MAC link layer and PHY physical layer, as well as 2 Uart interfaces. The real-time operation system uC/OS II v2.89 has been ported and LWIP protocol stack also runs on the system. The preverifying function is optional applying to different communication protocols. Therefore, it is effective to reduce the load and collisions over the Ethernet. Certified the gateway accomplished, two RS485 bus with Modbus Protocol could connect via Ethernet to achieve a low-cost, long distance, transparent and reliable data transmission.