NetToPLCSim extends the Siemens PLC Simulation Software "PLCSIM" by a TCP/IP network interface for variable services, so you can test your HMI/SCADA-Software together with PLCSIM without real hardware.

Version information

There are two versions of NetToPLCSim which are using a different interface to exchange data with PLCSim:

It's recommended to use the S7online-Version.


The S7online-version is using an inofficial interface to PLCSim, which is called S7online.

This is the same interface which is used for programming the PLCsim from the Simatic Manager. This interface "speaks" the S7-protocol, so NetToPLCSim has to wrap/unwrap the data into the network layer (TCP / IsoOnTcp).

The version supports multiple clients and multiple PLCsim instances.


The S7ProSim-version is using the official interface which PLCsim provides. This is a OCX which is called S7ProSim.

This interface has some limitations of the data areas you can get access to. Also this interface is rather slow. In this version, NetToPLCSim implements the all parts of the S7-Protocol which are used for variable access.

It does only support a single client and a single PLCsim instance.

This version is not developed any further. You can use it as example how to use the S7ProSim interface for your own applications (e.g. process simulations), or when you got problems with the S7online-Version.