Step7

STEP 7 is Siemens’ engineering software used to configure and program Siemens S7-300 and S7-400 programmable logic controllers (PLCs) within the SIMATIC family. It provides a project-oriented environment for hardware configuration, PLC programming, and diagnostics. Programming is commonly performed in ladder logic (LAD), function block diagram (FBD), and structured text (ST), with program blocks such as OBs, FCs, FBs, and DBs organizing the logic and data. STEP 7 integrates offline design of the control system with online monitoring and debugging, enabling engineers to configure I/O, networks, and communications for the PLC hardware.

The software traditionally works together with SIMATIC Manager to manage projects that include hardware configurations, network setups, and PLC code. It supports integration with industry networks such as MPI, Profibus, and Industrial Ethernet, facilitating communications between PLCs and peripheral devices, drives, and HMIs. STEP 7 also provides diagnostic tools and online editing features to monitor PLC status, view variable values, and troubleshoot in real time.

Historically, STEP 7 served as the core engineering tool for the S7-300 and S7-400 families and remains associated with the legacy STEP 7 Classic environment. In recent years, Siemens has shifted emphasis toward the TIA Portal, which consolidates STEP 7 functionality into a newer platform while offering migration paths for existing STEP 7 projects. As a result, STEP 7 is often considered a legacy or transitional tool, primarily used to maintain and update older projects or to support environments still running S7-300/400 controllers.