, which was released by Siemens to improve the stability and security of their safety-related programming environment. You can find the official download and documentation on the Siemens Industry Online Support (SIOS) Key Details for Download:

For an engineer, downloading V64 specifically usually implies a need to maintain or upgrade a specific generation of hardware without fully migrating to the newer TIA Portal (Totally Integrated Automation) environment. While TIA Portal is the current standard, thousands of operational plants worldwide still rely on the "Classic" STEP 7 architecture. Therefore, V64 serves as a critical lifeline for these existing infrastructures, ensuring they remain supported, secure, and compliant with safety regulations without requiring a costly and risky total system overhaul.

: V6.4 introduces "Increased password security" as a default option for safety programs.