Data Monitoring of S7 via MPI or Profibus port


Thread Starter

Hywel Thomas

I need to monitor a small amount of data from an S7 CPU316-DP (~8 REAL's @ 2s rate) for loop tuning. The CPU has an MPI port and a Profibus port, and I would like to be able to make selected data from a DB available at a PC over DDE. I have used OPC via Ethernet on other
systems, but this one does not have the CP316 Ethernet module. Does anyone know if there is any software available to monitor data over the MPI link (like an Online Variable Table in the Step7 programming package, which we have)
but then making this available to other applications via DDE? I don't mind writing something if the details of the S7/MPI protocol are available, but I suspect this is not the case.

Many thanks for any information.

Hywel Thomas

Manchester, UK

John deKrafft

Siemens has an ocx that will allow you to communicate with the plc but it is quite expensive (~ $1000). I don't think Siemens makes the protocol readily available.

If you use WinCC for the HMI you could trend it there. The data would also be available through ODBC.

Hakan Ozevin

You may think to use Siemens ProTool/Pro as SW and MPI cable as the HW. With this solution you do not get only an MPI driver, but also an HMI SW for monitoring purposes. The only problem may be the cost, which will be about 1000 USD.
Hello Thomas,

you have more possibilities. Just a few of them only. You can use SW called PRODAVE from Siemens, this SW contain the tool to set up the COM port on your PC to be able to communicate with Siemens PLC by using MPI/Profibus. You get a library for C++ and VB too ( take a look in "": ), my coleague had developed smart application by using this SW, ask him, I don't know if it is
ready ( "[email protected]", mailto:[email protected] ). You can use the SW products of "DELTALOGIC" company "": . Or you can visit the "": . The ATS company had developed DDE driver it could be the simplest solution for you. Demo of DDE driver could be downloaded from address mentioned above.
I wish you be successful.
Best regards
Pavel Horak