Copyright © 1998-2017 Luca Gallina

Runmode, programming Siemens PLCs

Free tools, hints, tips and tricks. Interesting and specialized applications are also on sale, all developed by programmers for programmers.

S7 Can Opener

Set and remove on the fly the KNOW_HOW_PROTECT

on S7-300/-400 blocks!

NOTE: it does NOT unlock latest S7 v5.5 “Block privacy” protection

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How to order

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Language supported: English only.

Download S7CanOpener v1.3 (demo version)

Download S7CanOpener manual

Current version is v2.0    
If you are a registered user and own an older release, contact us for a free update.

The automation software house will be no longer in business?   So, why should I put my hi-tech machinery in jeopardy?

Your machinery supplier or system integrator does no longer support the software they developed and you are in trouble with S7 PLC programs where some blocks say "block is protected"?

You lost your source code and you cannot access your compiled blocks anymore?

You like to keep just one copy of your blocks instead of maintaining both compiled and source copy of each block?

You like to toggle the know_how_protect keyword on-the-fly, without having to compile your blocks?

If you find yourself in one of these situations, the S7CanOpener can solve your problem!

S7CanOpener FAQs

Q: What's the S7CanOpener purpose?

A: the S7CanOpener can unlock S7 blocks protected with the "know_how_protect" keyword.

Q: Can it unlock also S7 libraries?

A: Yes, it works on S7programs (*.s7p) and S7libraries (*.s7l)

Q: Can it unlock Step7 v5.5 new “Block Privacy” protection ?

A: No, at the moment the tool is not able to decrypt such protection.

Q: I have a PLC that requires a password for online operations, can I use the S7CanOpener to defeat the password?

A: No. The S7CanOpener operates on projects stored on the hard disk, it does not operate online in the PLC memory and does not remove the password set in the CPU at hardware configuration level.

Q: Will I be able to read the comments within an unlocked block?

A: Yes, if the original block contained comments.

Q: I have some SCL or CFC blocks, can I reverse the code to obtain the source file?

A: No. In case you have SCL, CFC, GRAPH7, HIGRAPH blocks, once unlocking them you will get the compiled version of the block or, in other words, plain STL code with no comments and no variables name at all.  If you expected the full-source text file, it is not possible: in that case your only chance is to get the original SCL or CFC source file.  On the other hand, if you are however interested in the blocks' contents, you have a way to peep into the STL version of the code.

Q: Can I lock/unlock UDTs?

A: Yes, from version v1.4 you can lock also UDT (User Data Type) blocks. Unlike all other blocks (OB, FC,FB), a protected UDT cannot be modified but its contents can be displayed.

Q: Can I unlock SFCs and SFBs?

A: SFCs and SFBs cannot be unlocked since they are functions stored in the PLC's system memory and cannot be read. What we see and use in S7 is just the block's interface (parameters assignment) and not the complete block.  Offline SFCs and SFBs contain no S7 code.

Euro 50.00

Euro 50.00 + 22% IVA/VAT tax = Euro 61.00

Price and tax (when applicable)

Shipping and billing

The program, registration code and invoice will be sent via e-mail upon payment.

We normally deliver within 24 hours from payment.