Communication with Simatic S7-300/400

ipConvLite offers a universal solution to connect Siemens® Simatic® devices of the S7-300/400 family to protocols such as IEC 60870-5-101, IEC 60870-5-103, IEC 60870-5-104, Telegyr 809, OPC. And you do not even need to modify any Simatic programming already done!

The advantages at a glance
  • direct access to all data areas of a Simatic S7-300/400 controller via the FETCH/WRITE interface
  • no Simatic programming necessary
  • fast integration 'on the fly', no service interruption of existing systems
  • simultaneous connection of several controllers
  • configurable data areas and access cycles
  • object oriented access, data is NOT transferred blockwise, but individual data points
  • may be used in combination with all implemented protocol stacks (see also ipConvLite)
  • supports nodes, i.e. simultaneous communication with multiple devices using different protocols
  • time stamping on change of data (configurable)
  • time synching via Network Time Protocol (NTP), communication protocol or external GPS/DCF77 module
  • redundant operation possible

The FETCH/WRITE API enables accessing of S7 PLC data. This allows direct access to data packets, inputs / outputs, flags, peripheral inputs / outputs, timers and counters. This does not affect the S7 PLC programming. All that is needed is the establishing of an additional communication link.

The following connection types are possible:

  • TCP
  • ISO-over-TCP (RFC 1006)
  • ISO 8073 (Sinec-H1)
  • 3964R
  • You can configure communication via the FETCH/WRITE interface by specifying the size and location of system data areas and access speed.

    Data are extracted as individual information objects, and they can also be transferred as individual information objects. Simatic addresses and target system addresses may be freely assigned. This method can also be used to limit the data volume to be transmitted to what is absolutely necessary. An Excel file can be used to configure device data points (see also ipConvLite. Of course, the ipConvLite standard functions also include data point processing, scaling and conversion.

    Information can be time-stamped locally in ipConvLite to keep track of changes. This means the internal clock of ipConvLite must be synchronized first. You can do this using the installed protocol (e.g. IEC 60870-5-101) , NTP or an external GPS/DCF77 module.

    The state of communications with Simatic determines information object quality attributes,i.e. if IEC 60870-5-101 is used as the target protocol, , and the connection to Simatic is disrupted, all the information objects transmitted take the value “invalid” or “not topical”. Upon reconnection, all data points take the value "valid" and are transmitted to the control system with their currently valid values.

    For further details see ipConvLite.


    This example shows a gateway upstreaming data to a remote control unit via the IEC 60870-5-101 protocol. Process data is also provided for local monitoring and control via the OPC DA XML interface.
    This example shows a redundant configuration. The redundant coupling can be realized over a serial RS232 line or over Ethernet.