title: S7 200/1200 to oracle database data transfer. Choosing OPC. Ways of communication with WinCC6
body: <p>I'm a newbie in PLC.<br>
  Currently I have an s7-200 cpu + cp243-1 and an s7-1200 cpu connected to a factory network (ethernet). The goal is to transfer data to an Oracle database from these two cpus. My part of work is to convey data to the opc server. I'm considering 3 variants:</p>
  
  <p>-<strong>Pc Access OPC</strong> (6ES7840-2CC01-0YX0). Really cheap, but I've noticed that there is "SINGLE LICENSE F.1 INSTALLATION". I wonder what it means? Does it mean that I'll be able to install it on one machine for multiple times or just one time? Also, as far as I can see on the web, there could be some issues when working with S7-1200 because it was originally designed to work with s7-200.</p>
  
  <p>-<strong>Simatic Net OPC</strong>. What are the advantages of this one? </p>
  
  <p>-<strong>Matrikon Siemens S7 PLC OPC Server</strong>. Seems a good one, but expensive.</p>
  
  <p>I need to transfer only about 30 tags and that keeps me from spending money on Matrikon and in this case my priority is Pc access, but some say that it can be unstable sometimes.
  Btw I have a WinCC 6 (not flexible) installed on some computers in a factory network. As far as I know WinCC 6 includes its own opc server (not sure). So is it possible to transfer tags there? So far I've found 2 sources:</p>
  
  <p><a href="http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&amp;lang=en&amp;objid=21915573&amp;caller=view" rel="nofollow">Here they say that OPC is needed to communicate with WinCC.</a></p>
  
  <p><a href="http://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&amp;lang=en&amp;objid=14587200&amp;caller=view" rel="nofollow">Here they imply that additional opc is not needed. Comes as a part of WinCC..</a></p>
  
  <p>Honestly, I'm not experienced with WinCC, so I need your advice.</p>