How can i simcom a7682e module as a modbus tcp server. i use at+serverstart module. it returns me "OK" but i cannot connect with modbus poll or i cannot ping to ip addr with command prompt. i get server ip address using at+ipaddr command. socket is 502. what is wrong?
There is too much context missing from your question.
The SimCom A7682E module A7682E is a comms module, but I don't see that it supports Modbus.
I suspect you are using the SimCom module to connect to something that is a Modbus server, but without information I can only guess.