Siemens Connection via Ethernet

Can some-one please help me.

I have a Siemens 317 2DP\PN CPU on a packaging line.
I would like to know that is the most effiecient way to get a couple of values from the PLC via ethernet to a PC.
If I use OPC how does it work ?

Ethernet/databases etc. are new for me.

We use Kepserver on any PC.
There are MANY ways to do what you want.

Can you explain how it works or can I go and read about it ?

Type in Kepserver in Google.

It is off the shelf software that is readily available that will communicate to various platforms, and transitions them to a location for you to use the data.