S7 Protocol (RFC 1006)

  • The S7 Protocol (RFC 1006) enables the connection of S7 automation devices with any communication partner. It provides direct access to the S7 user memory without changes in the user application itself.

    As shown in the figure below, the S7 Protocol (RFC 1006) supports a variety of different transportation methods.For the usage of TCP/IP, only a communication unit (CP) for Ethernet connection or alternatively an onboard Ethernet interface that supports ISOonTCP (RFC1006) must be available.

    ISO - OSI classification
    chart: ISO - OSI classification

    In comparison to Simatic Fetch/Write, the S7 Protocol (RFC 1006) allows the addressing of all internal on the PLC side, i.e. no limitation on the data blocks (DB). Depending on the PLC only small or no configuration changes at all must be made to support the S7 Protocol (RFC 1006).

    The SIMATIC® S7 series supports the protocol ISO-on-TCP natively in passive mode, i.e. it operates as a server and accepts client connections.

7 Application Layer S7 Protocol
6 Presentation Layer n/a
5 Session Layer n/a
4 Transport Layer ISO-on-TCP (RFC 1006)
TCP (RFC 793)
3 Network Layer IP (RFC 791)
2 Link Layer IP (RFC 894)
1 Physical Layer Ethernet (IEEE 802.3)
Available Protocol Stacks

S7 Protocol, Client

Applicable Products
  • ipConv

    Universal protocol converter for highest degree of flexibility

  • ipConvLite

    Universal protocol converter for small and distributed applications

  • ipConvLite/MEC2PBS

    Universal protocol converter with integrated PROFIBUS-DP, slave interface

  • ipConvLite/MEC2PBM

    Universal protocol converter with integrated PROFIBUS-DP, master interface

  • ipConvLite/MEC2PNS

    Universal protocol converter with integrated PROFINET-IO, slave interface

  • ipConvOPC

    Windows software package for universal conversion between diverse standard protocols

  • ipConv/VM

    Universal protocol conversion for VMware Workstation and VMware ESXi

  • ipConv/Cloud

    Universal protocol conversion for the cloud environment or Linux based edge devices

  • ip4Cloud

    Link critical processes securely to IT/Cloud/SCADA services

  • ip4Cloud/SEC3PB

    Capture PROFIBUS data by eavesdropping and transmit it to Cloud/IT or SCADA services

  • ip4Cloud/SEC3IO

    Switch and monitor digital I/O states to transmit them to IT/Cloud/SCADA services

  • ipELB

    4-Port Ethernet Line Breaker with relay controlled Ethernet ports and integrated I/O module