connecting s7 300 siemens plcs together


Thread Starter

suleyman igde

There is 3 individual machines with s7 300 siemens
plc. We want to make one scada system (and workstations) to all machines (not individual scadas)

machine #1
s7 300 cpu 316-2-dp siemens plc
20 profibus slaves (drivers and et200 modules)
1 pc (connected with mpi port to the plc)

machine #2
s7 300 cpu 315-2-dp siemens plc
NO profibus slaves
1 pc (connected with mpi port to the plc)

machine #3
NO plc (but there is a lot of et200l sc)
40 profibus slaves (drivers and et200 modules)
1 pc(a) connected to profibus
1 pc(b)connected to pc(a) with ethernet

Can you help us about
1-how can we connect these plc's on same network
2-various network type's,
3-hardware requirements,
4-software requirements.

Note: we want to use opc server at first but it
can be change. And can we do this with a prog.
language (example:delphi) instead of scada.
Because there is too much client workstations.

I think one solution is;
1 pc with 3 profibus pci card,
1 opc server (1 or more ?) for profibus dp
1 scada sever (which one genesis?) or if possible

is this solution works?
what is your different ideas?
what is the inexpensive way configuration?
what is the most powerfull way conf.?

suleyman igde
[email protected]
You can make a MPI network, but first you must look what pc card (CP5412, CP5613, .. etc) you use to connect the DP slaves of the third
machine to the PC.

If your PC (third machine) card has an available MPI port you would can connect the two S7-300 and PC in one whole MPI network.

In this manner you will have one MPI network with two PLCs and one PC and three DPs subnetworks for each MPI device.

Luis Rios
[email protected]
Let me extend my last reply ...

All SIEMENS S7 PLCS with DP inteface (as you have) have a MPI interface, you can use it to daisy chain the two PLC and the PC(a) (if you Profibus PC card do not have a MPI port you can replace it with one that have one or put another
card with that port).

The above is turns the things easy, you only need to connect three ports, configure the MPI network and then install a DDE/OPC MPI server in the third
machine PC(a) and use it (the server) to spread the process information, as you like (maybe using Delphi as you write), over the Ethernet network.

Also you can do the follow: if you have in the third machine PC(a) a SIEMENS CP5412 (A2) profibus card, you can connect the PLCs and PC(a) using its DP ports, then in the PC(a) you must configure by software two S7-Comunication
Link, one between the CP5412 (A2) and the PLC of machine #1 and another between the CP5412 (A2) and the PLC of machine #2. In this case you need install a DDE/OPC server for S7-Comunication in the PC(a) (I used Siemens DDE/OPC server and Wonderware I/O server, i like more Siemens because you access the data structure of the PLC graphically as a tree and you can copy and past DDE link between applications). In the past i implemented that solution with great success.

Also you must have in mind that you have a lot of DP devices therfore, if you consider the last solution, you will need network repeater each 32 devices.

Luis Rios
[email protected]

p.d.: I will really appreciate that Mr. Ashish Atre share his solution with us.

Zan Von Flue

I would also use a MPI metwork for the first 2 PLC's, the MPI card installed on the 3rd PC.
The Scada/HMI can also be installed on the third PC. If OPC is needed, we use iFix from Intellution, easy to install and work with. It has both HMI/SCADA in one. The Demo works full for 2 hours. But, Siemens has also a OPC server. The Client(HMI) is seperate. It's alittle bit more complicated installing but works better. However I'm not excited about OPC, if possible I would still stay with DDE even though I heard it is dying. It works good with windows stuff like
Excel etc.
Here a NT/2000 system is needed, at least a 600MHz computer (for the Scada(iFix) alone!) and MPI card (you have profibus). I had everything on 1.2 GB harddrive.

Comtrol's DeviceMaster was able to solve all my problems connecting simens plcs together. I've always been a fan of the Rocketport - but the Devicemaster is a site to be seen! Thank you Comtrol!

Donald Pittendrigh

Hello Suleyman

Would you mind giving us a description of the system as implemented with device master, it sounds very interesting.

Donald P
I have had nothing but issues with my DeviceMaster RTS. It is constantly down. It seems out of any of the embedded servers I have tried -- Lantronix XPORT is by far the best. The fact that it has data rates between 300 to 230 kbps is what makes it my favorite EDS.

Carry J.