It's difficult to help you, since you don't ask any specific question. Siplus CPU is the same CPU as normal, except it has conformal coating applied.

Now UDP stands for user defined protocol - you're should be the first to know how you did define your protocol.

You will need first a manual where is a description of communication functions TCON, TDISCON, USEND.

If you are using Step7, download OC Wizard and examples:

http://support.automation.siemens.com/WW/view/en/25209116

If you have a protocol description/code post it.

Exactly, you can program ethernet ports on CPU freely. With UDP you can expect two possible scenarios:

1.CPU will stream out data in custom format without acknowledgment

2. A complex handshaking protocol between CPU and PC, difficult to implement in CPU