Android : Android app to PLC communication

I want to write an android app to communicate with the PLC devices which this app is supposed to send command and receive some data from the PLC.

My android device and the PLC device is connected to same local network.

If I know the PLC IP address, how can I connect and communicate with it via network?

I'm looking for right way of doing that, some search keys or java libraries will helps.

I found some P2P connection classes in android SDK, but I don't know if it helps. or I don't know if socket programming works for this problem.