The core safety functionality for STEP 7 "Classic" (V5.x) is managed through the V5.4 SP5 release:
For more information on S7 Distributed Safety V5.7, please refer to the following resources: s7 distributed safety v57 download link
To download S7 Distributed Safety V5.7, you can visit the official Siemens website or other authorized sources: The core safety functionality for STEP 7 "Classic" (V5