protect FC or FB

how can I hide inside code of FC or FB in siemens s7 ?

Create source from fc or fb. Add know_how_protect to the source and recompile. Than the block is "protected". Another option is the use of a tool to add remove the know_how_protection.

As mentioned add the text Know_How_Protect after the I/O/Stat/Temp parameters in the soutrce for each block you want to protect then re-compile.

You would need to keep the source seperate then, export the protected blocks and keep somewhere.

The only down side is this is very easy to open.

One way I've seen to make it difficult to read the code is to use UDT's extensively and then remove the UDT's and symbols from the source code. People can still get in but cannot easily dedcipher the code.

thank you it was very helpful. you mentioned its very easy to open a protected block can you explain about it .it sounds intersting

Have a look here for unlocking blocks.... http://www.plctalk.net/qanda/showpost.php?p=116925&postcount=7

Also widely used but not free


http://www.runmode.com/s7canopener.html