Read data from Simatic S7-400

Gentlemen,

Is there a dll library to allow me access the SIMATIC S7-400 using C# or VB.NET?

We're having this SIMATIC S7-400 installed in our Silos Plant and it does the basic jobs like moving materials from Silos to Load Bins and so on.

We will install Load Cells in the load bins so that we know the materials loaded from the bins and we keep track of them.

I honestly know no STL, SCL, LAD nor FBD. I tried to develop an application using high language like C# and I used the provided dll libraries with S7 PRODAVE but couldn't.

Please advise.

I am assuming you are using the Load Cell modules Siemens has. I think you should forget trying to use C++ and learn SCL. You should get the source code from the installer and then, using Step7 Professional, you will have SCL and it would be easy for you to learn. Prodavi is designed to use as an HMI to communicate through the programming port and gather data with MPI to the CPU, not to control the I/O.

Thanks RRobbins.

Does that mean that even OPC Server/Client wouldn't be a solution at all?

I like SCL it looks like as if you're writing code in Pascal but I'm not sure how fast will that be.

Thanks in advance for your help.

OPC Cliet / Server is an excellent way for data collection, set values, etc. Are you trying to write your own, over MPI or TCP? If you are going TCP, I have attached a sample VB ap that will help you get started, using Native TCP.

Thanks again RRobbins.

Excellent. In fact I'm going to use MPI protocol and as per your advice, I'm going to purchase Matrikon OPC Server for Siemens MPI and OPCClientNET so that I can develop my own application using C#.

The bottom line is that all intake, transfer and load processes should be done through the application I'm going to develop (what's PIC). That's operators will have to stop using the current control system which does basic materials movements and use the application I'm going to develop.

I'd like to hear your recommendation before I go ahead and purchase the above software.

P.S. I'm sure the attached file will be of a great help when I try to connect to the PLC using TCP/IP protocol.

Looking forward to hearing your recommendation.

For those who would like to communicate with any OPC server using .NET Framework language, they may use OPC.ClientX.NET. I used MOS (Merz OPC Server) to communicate with the SIMATIC S7-400 and developed my application in C# to communicate with the MOS. The most interesting part is when you develop your ASP.NET application and let remote users control some parts of the plant.