S7-300 Software Redundancy

Dear Experts,

I am working on a system with S7-300 software redundancy due to high availability requirements of the control logic. My question is, can I do it with a single profibus network? I came to this question because there is a DC drive with profibus interface that is controlled by the PLC system and should be online always on either station A(master) or B(back-up). Need some inputs on this issues.

Thanks,
Alex Senagan
Republic of the Philippines

how would you achieve any communication redundancy with just 1 connection ?

Redundancy is a generic term that need specific definitions. You can achieve plc redundancy only with your setup (not i/0 and device) but it is useless since parts that is more willing to fail is probably i/os...

Real and complete redundancy is made using s7-400h

you have to use a Y-Link [FONT=Arial, sans-serif] 6ES7197-1LA04-0XA0[/FONT]
Is a module that connects two segments profibus coming out with a single cable

Sorry, Y-Link doesn't work on simatic 300