WinCC with 2 connections to a plc

[lauwerstim]

Is it possible in WinCC to connect to a plc via 2 different networks?

My situation is the following: i have 8 plc's (S7-300), each with two ethernet cards, each card is connected to a ethernet-fiber ring by means of a Scalance switch (the ring itself is plastic fiber, connection between CP-card and switch is normal copper)

So we have 2 ethernet rings, communicatian between PLC's is easy to do this way but connecting the WinCC looks harde because the WinCC has to look to connection 1 until the connection get dropped for 1 plc, then it has to look to the other connection.

So, is it possible?

ps: I know a double ring is quite useless but it's a brain f*rt from a client and he absolutely wants it.

 

[JesperMP]

WinCC or WinCC Flexible ?
S7ONLINE or SoftBus (= "PC Station") ?

 

[lauwerstim]

WinCC v7

S7ONLINE

 

[JesperMP]

In Set PG/PC Interface, you can try to create two access points, i.e. S7ONL_1 and S7ONL_2, and assign each its own ethernet card.
Then in WinCC I am guessing you can specify S7ONL_1 and S7ONL_2 in stead of the default S7ONLINE.
Not sure if it will work, but easy to try.

 

[lauwerstim]

Yeah, i've tried it and it works but not how I want it. Now you can look either to the first or second ring. But if on both rings there's an error, you always loose 1 plc because you can't look at both rings this way.

If I have a plc with a bad cp-card on ring 1 and another plc with a bad cp-card on ring 2, it should be able to see both PLC's on their working CP-card (ok, this is very far fetched but it's what the client wants)

 

[JesperMP]

There is a Simatic Net software option called Redconnect that will do it.

Maybe there is also a do-it-yourself approach. It could be possible to program two connections and use automatic changeover. There was a recent thread about this, but it was for WinCC Flexible, not WinCC.

edit: It is not a stupid customer requirement. He obviously has given it some thought, and want a system with networking redundancy. Quite sensible if this is a critical part of a large system.

 

[lauwerstim]

I'll try the redconnect thing and look up the WinCC flex thread.

Thanks again for the help.

 

[lauwerstim]

....

edit: It is not a stupid customer requirement. He obviously has given it some thought, and want a system with networking redundancy. Quite sensible if this is a critical part of a large system.

That's just it, it's not really critical and there's redundancy with a single ring too.
Extra: there's a coupling cel with one CPU315, if that fails, the entire project shuts down. Would make more sens to make this plc redundant and keep using a normal ring with OLM's (like we used to use in previous projects and never gave problems)

 

[JesperMP]

The dual rings with separate conenctions to each PLC/PC has a bit more redundant coverage than the single ring with one connection per PLC/PC.

For most applications, a single ring as a network backbone is a good compromise.
You could try to argue that the redundant PLC makes more sense. That you have references already with that setup may help convince your customer.