connecting S7 with wincc


Thread Starter



We have six S7 300+2DP plc that work separately "e.g.
plc-1 and plc-2 and plc-3 and plc-4 and plc-5 and

each plcs work separately with its op170B and cpus aren't link together. For connecting plcs together and to three wincc station what should I do? I want to know, should I configure a new project including six simatic station 300?
Means i must create a new project for example "total" and configure six simatic station 300 according to stations that have been configured In six separate projects? and then configure all CPUs as DP-Master with bus profile "Standard". in Net pro of total project we will see all cpus that connected to profibus DP sub net. if i configure in each plc, its CPU as DP-Master with bus profile "Standard" without define new project "total" means in Netpro only one cpu appeared, will be ok? If one cpu in network go to fault, we would have fault In all cpu?

If we want to have 3 station as wincc HMI, can I use
from cp5611? do I need another software? should I define PG/PC or other station or simatic pc station for wincc station?

Best regads

david mertens

Athough it is possible to connect WinCC to a PLC using the DP protocol, this is rarely done. The DP protocol is a master slave protocol which supports only one cyclic master. This means that in your configuration with DP you could only have 1 WinCC standalone or server connected as a master to the PLCs. You can connect the 2 other PC stations to the server which would give you 3 operator stations. However there is only one connected to the PLCs and if this server goes down you don't have a backup.
If you want to use profibus to connect the PLCs to the PCs you should use FMS protocol which is not a master-slave but a peer to peer protocol allowing multiple stations to access the PLCs. However this protocol is (as far as I know) not supported by the DP ports on the CPU. The only way to make this kind of connection would be by adding a CP343-5 card in each PLC rack.

A better solution would be to go to the ethernet protocol and instead of a CP343-5 add a CP343-1. This is the way to a flexible and expandable S7-WinCC solution. Also I would suggest to use 2 redundant WinCC servers and 1 client this would give you 3 operator stations with redundancy at a price that is below the price of 3 stand-alone WinCC stations (Except if only very little data are needed <8K tags) and gives better availability and online changeability than 1 server with 2 clients.
It's best to have all six PLCs in one project as well as WinCC integrated in Step 7 project by inserting a PC station.

If 3 independent stations is configured, then each station must have a CP5611 card.

If setting up as server-client configuration then only one CP5611 is required.
Wrong on all accounts. You can have up to 64 S7315-2DP PLCs connected to one WinCC station and there is no need to use FMS; however, I wouldn't do it that way if you have a lot of DP I/O hanging on the network. Use the MPI ports on the PLC, they are better geared for communications.

Ron P
Who cares? WinCC uses S7 communications to the S7 315 PLC. This allows you to have multiple masters on one network.

Ron P
Yea--finally someone got it right. That is the beauty of the Siemens TIA approach, it's easy.

Ron P
Although true the original proposal that Ethernet is the best communications solution is still valid, that uses S7 functions as well.


Powers, Ron SEA

Excellent observation, but the original poster wanted to connect the WinCC Stations via DP. Connecting via Ethernet would be my choice. I would use the new CP343-1 Lean which is half the price of the CP343-1. Same functionality; however, you can only configured 8 S7 connections.

Ron P.