profibus to ethernet

Hi All,
I looking for easy solution for my task. My customer want to collect all scada visualisations to one PC. There are six PLC's(Siemens CPU315,CPU315,CPU400)and each PLC separetly has own SCADA. Customer want to collect all visualisation to one SCADA. Some PC's are connected to PLC by profibus and some by ethernet. I had idea to connect all PLC by Ethernet to one PC. And problem is that this PLC's are far away from control room where this SCADA will exist. I don't like to pull new cables so I had idea to use this profibus cables which are already there. Is possible to use this profibus cable to another SCADA ? eg. by using converter to ethernet?? Thanks for all sugestions

It is possible, but I do not recommend to join separate Profibus networks into one network as you suggest.
The performance of the profibus network will drop (by a factor 10).
The probability of errors will increase.
The consecuense of a Profibus error will be more severe, since now 6 systems will go down in stead of 1 (or you add repeaters to isolate an error, which means more costs).
The system will be very inflexible and hard to maintain and troubleshoot.

I suggest that your try one of these:
1. Add ethernet to each CPU. That is the one I would chose.
2. Use OPC on each PC, and forward the OPC connection to the data collection PC. Traditionally DCOM is supposed to let this be possible. However I have heard endless stories about DCOM problems. Instead I suggest you invest in OPC software that acts as a middleware between the OPC server on one PC and the OPC client on the other PC.
3. Use remote operation software on each PC to allow remote visualisation and control on another PC. I suggest Teamviewer. Cheapskate solution, but it works.