README updated

Author: goddland16

README.md

@@ -3,8 +3,23 @@ README
 
 Overview
 --------
-This is an Arduino library for communicating with Modbus server over Ethernet (via TCP protocol).
+This is an Arduino library for communicating with Modbus server over Ethernet (via TCP protocol). Arduino will act as a Modbus client and request data from Modbus Server(which could be any device or PLC).
 
+Hardware
+--------
+This library has been tested with an Arduino [Mega](https://www.arduino.cc/en/Main/ArduinoBoardMega) with following Compatible Ethernet ICs.
+
+1. Wizent W5100 - [Ethernet library](https://www.arduino.cc/en/Reference/Ethernet).
+2. ENC28J60 - [UIPEthernet library](https://github.com/UIPEthernet/UIPEthernet).
+
+Note: It can be made compatible with Wiznet W5500 model, by adding new [Ethernet2 library](https://github.com/adafruit/Ethernet2) in the header file.
+
+Settings
+--------
+Depending on the ic used set the following Macros.
+
+1. define WIZNET_W5100 = 0
+2. define ENC28J60     = 1
 
 Features
 --------
@@ -29,10 +44,5 @@ Registers
 
 
 
-Hardware
---------
-This library has been tested with an Arduino [Mega](https://www.arduino.cc/en/Main/ArduinoBoardMega) with following Compatible Ethernet ICs.
 
-1. Wizent W5100 - [Ethernet library](https://www.arduino.cc/en/Reference/Ethernet).
-2. ENC28J60 - [UIPEthernet library](https://github.com/UIPEthernet/UIPEthernet).