Modbus Protol

Projects Networking, Protocols, and Devices
1

Dear all,
I am trying to implement modbus protocol with arduino UNo Board.Can someone suggest me the Pin configuration with arduino uno board fro modbus protocol with example codes.
Is there any library available for Modbus protocol with arduino. If any link with more example help me to learn

Actual purpose: I am having SCADA system which have modbus protocol acts as mAster. I have 2 arduino boards acting as slave.
I wanted to transmit Serial out via modbus protocol.

http://playground.arduino.cc/Code/ModbusMaster#.UzPmV6iSwXu

2

I have GOne through lot of link

http://forum.infiniteautomation.com/forum/posts/list/0/567.page#2721
https://code.google.com/p/simple-modbus/