Glossary · Industrial communication
S7 protocol
Also known as: S7 communication, S7comm
German: S7-Protokoll
In industrial communication, the S7 protocol is Siemens' proprietary communication protocol for SIMATIC S7 controllers, used for programming, diagnostics and data exchange with HMIs, SCADA and other controllers, typically over ISO-on-TCP on port 102.
- Industrial communication
- Vendor product
- OT security
In one sentence
The S7 protocol is Siemens' proprietary protocol for SIMATIC S7 controllers, used for programming, HMI and data exchange.
Example
A third-party SCADA driver reads data blocks from an S7-300 controller via the S7 protocol, while newer S7-1500 controllers are connected via OPC UA.
How it applies
- Engineering: Many HMIs, SCADA systems and data collection tools include S7 drivers. Newer controller generations use extended and secured variants of the protocol, and some features of third-party drivers depend on settings in the controller (such as allowing PUT/GET access).
- Security: The classic S7 protocol has little or no authentication, so anyone with network access could read or write data. Protection comes from network segmentation, protocol-aware firewalls, access-level settings in the controller and, where available, the secured protocol variants.
- Integration: For vendor-independent integration, OPC Unified Architecture (OPC UA) is increasingly used instead.
- Documentation: The documentation team documents which systems access controllers via S7, which data areas they use and which protection settings are active.
Keep in mind: Product names, protocol variants and security features change. Check the vendor's current documentation for supported controllers and settings.