Avalanche

I was hoping to avoid using an OPC. Find some drivers somewhere but....

I am new to the PLC world but an old hat at DAQ and LV. I now need to connect a PC with a Siemens S7-200 PLC in order to do data logging, friendly interface, and a small amount of writing to the PLC. I don't know where to start. The PLC has an RS485 on it and we have the RS232-RS485 PPI cable from Siemens. What else do I need to do this? Are there Drivers? I would like to treat the PLC as a DAQ device and read the line states.