I have Arduino Uno and ethernet shield HANRUN HR911105A 17/02
I want it act as Modbus SERVER , 40001 to 400010 should have some Values which I will try to read from another PLC
How can I do that -I am new
I assume that because you mention the Ethernet shield, that you are hoping to use Modbus TCP, rather than Modbus RTU?
You could start with the ArduinoModbus library.
If that doesn't suit your needs, then Google is your friend. A quick search for "arduino modbus tcp" will provide lots of hits.