Which are you currently using (e.g., Step 7 V5.6, TIA Portal V17)?
If you unlock an SCL (Structured Control Language) or CFC (Continuous Function Chart) block, you will not get the original source text file. You will receive the compiled version of the block, which appears as plain STL (Statement List) code without comments, variable names, or graphical layouts. This can be difficult to understand, but it is often the only way to recover the logic of a lost program.
It can remove the KNOW_HOW_PROTECT attribute from FBs, FCs, OBs, and DBs on the fly.
The term "S7 Can Opener" is a slang term for a set of third-party utilities designed to interact with Siemens S7 PLCs at a low level. The most famous of these is a command-line tool often simply called s7canopener.exe or associated with the library and "S7-200 Password Cracker" variants.
You can download and run the program without paying. However, in Demo mode, the software will only allow you to view the blocks and see their protection status. It will not actually remove the KNOW_HOW_PROTECT flag or allow you to modify the project files. To actually make changes, you must register the software.
While the S7 can opener software offers several benefits, there are some potential issues and limitations to consider: