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Modbus TCP Server-Client communication through Ethernet switch

Associate II


I'm using 2 STM32F4 MCUs for Modbus TCP Server/Client implementation based on LWIP. One MCU as a Client and other one as a Server. I have connect both MCUs through D-Link DES-1016D ethernet switch.

The problem is when I connect both MCUs directly (ie: without Ethernet switch) both Server-Client communicates properly. But if I connect them through switch, communication breaks from server side for some time and reconnects again.

If I ping the IP of Client it responds continuously. But when I ping the IP of Server, it responds for sometime and hit Request timeout for sometime.Server IP Ping testServer IP Ping test

Because some other TCP connections also are in my setup so I need to connect both the MCUs through switch only. Does anyone already succeed implementing such behavior?


Thanks in advance.


Christian N
ST Employee

Hello Preeti,

Thank you for contacting STMicroelectronics. Your inquiry is being escalated for specialized support.

Kind Regards,


ST Support