Ethernet VISA read timeout

[SKim.1761]

I am using stm32f4 for lwip ethernet

 

It works nice with my custom monitoring program, hercules or etc

 

But in VISA instrument monitoring program it make some problem

 

RsVisaTester7.2.3 is now I am using 

 

When do Query with my device that bring data exactly but TMO(timeout) occuried

 

My code is take the client's ip address and save it on transmit socket

 

After parsing it transmit with saved one

 

Is there anything to solve this problem?

 

thank you