A Simple example to understand DNP3 protocol

[Siddharth Chhokar]

Hello,

Could someone share a basic example of Master and outstation simulator talking each other, to understand DNP3 protocol ?
Also, if possible please share set of Java APIs to implemenet DNP3 protocol in a Master and outstation simulator program.
Any information, any important document or link would also be very helpfull.

Thanks
Siddharth