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only one block read-write, the rest read-only?

Created by: peva at: 1/18/2010 9:03 AM (7 Replies)

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1/18/2010 9:03 AM	Rate (0)
peva Posts: 38 Rating: (0)	Hi all, we use a third-party S7-300 project, and we would like to add a functionality to it. The easiest way would be by adding one FB/FC, with our code. The problem here is, that the manufacturer of the project wants to preserve the project in the "read-only" mode. To add our FB/FC would of course mean that we will need to modify it, and maintain it later on. They propose to add an external PLC, comunicating with inputs-outputs. This seems to me an overkill for such a simple problem. But is there a solution so that both parties would be satisfied: i.e. we will have a read-only access to all blocks but the "our" one, we will have a read-write access to our block? Thank you in advance, Petr
peva Posts: 38 Rating: (0)
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1/18/2010 9:24 AM	Rate (0)
UMENCHO Diamond Member Joined: 3/21/2006 Last visit: 4/12/2023 Posts: 10221 Rating: (1176)	Hello, If you put write password this will be valid for all program. A user who does not know the password can then read the program in the CPU, without entering a password. However, he cannot make changes within the program. Perhaps in your case would be helpful to use block protection (Know_How_Protect). You can find more information about this under "Block protection (Know_How_Protect) for DBs, FBs and FCs" - entry ID: 10025431. Hope this helps. Best regards, Hristo Mihalev
	Last edited by: UMENCHO at: 1/18/2010 9:25 AM
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1/18/2010 2:32 PM	Rate (2)
fritz Diamond Expert Joined: 10/7/2005 Last visit: 5/29/2023 Posts: 2965 Rating: (1025)	Hello peva I must admit I am a bit confused. If the manufacturer of the project currently uses PLC wide "write protection" (set in theCPU properties from HWconfig)you will need to get the password from the manufacturer to be able to download your new block (and the one from which you want to call it). Once you have the password, you will always be able to modify and download your blockagain but assuming the end customer does not have this password will still be unable to changethe manufacturers program (and your new block will be write protetced in the PLC too now). Wouldn't this be the easiest solution (the trick will be to get thepassword from the manufacturer)? Assuming you really want the give the customer read/write access to your new block but keep all existing blocks as "read only", you will first of all again have to get the "write protection" password from the manufacturer, change the HWconfig (remove the write protection) and download it. Rather than doing Know_How_Protect (which would mean that the end customer can't monitor Blocks anymore), youcould thereafter use the"Store Read only .." functionality to create "read only" versions of all manufacturers blocks (make sure to have a backup copy of all Blocks before you save them as a read only copy, the "Store Read only .."is available in later Step 7 versions from the File menu when a Block is open). This now means that the offline version of the individual read only saved Blocks can't be changed anymore,rather than having a PLC wide write protection(which is what I believe you want to achieve). NOTE: The end customer will now be able to use forcing and Variable Table related "writes" into the PLC (which is something he can't do if PLC wide "write protection" is set and the manufacturer mayobject to this). Food for thought anyway andI hope this helps
	Cheers fritz The advice and opinion given in this thread is that of the author and does not necessarily reflect the views of I S Systems Pty Limited. To find out how I S Systems can help you with your automation needs please visit www.issystems.com.au.
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1/19/2010 8:14 AM	Rate (0)
peva Posts: 38 Rating: (0)	UMENCHO Hello, If you put write password this will be valid for all program. A user who does not know the password can then read the program in the CPU, without entering a password. However, he cannot make changes within the program. Perhaps in your case would be helpful to use block protection (Know_How_Protect). You can find more information about this under "Block protection (Know_How_Protect) for DBs, FBs and FCs" - entry ID: 10025431. Hope this helps. Best regards, Hristo Mihalev Hristo, thanks for your input. The Know_How_Protect unfortunatedly means, that we won't be able to monitor the block anymore. So we can't use this option. Best regards, Petr
peva Posts: 38 Rating: (0)
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1/19/2010 8:34 AM	Rate (0)
peva Posts: 38 Rating: (0)	fritz Hello peva I must admit I am a bit confused. If the manufacturer of the project currently uses PLC wide "write protection" (set in theCPU properties from HWconfig)you will need to get the password from the manufacturer to be able to download your new block (and the one from which you want to call it). Once you have the password, you will always be able to modify and download your blockagain but assuming the end customer does not have this password will still be unable to changethe manufacturers program (and your new block will be write protetced in the PLC too now). Wouldn't this be the easiest solution (the trick will be to get thepassword from the manufacturer)? Hi Fritz, sorry, I didn't explain our problem quite well. The problem is, that our manufacturer doesn't want to give us the permission to modify his part of the program. So he won't give us the password. He proposes us, that we should add an external PLC, and he will send us necessary information via inputs/outputs. This is of course costly solution and it needs quite a lot of work. The main problem here is, let's say, rather "political" than technical. That means, also that it's more complicated than pure technical problem. fritz Assuming you really want the give the customer read/write access to your new block but keep all existing blocks as "read only", you will first of all again have to get the "write protection" password from the manufacturer, change the HWconfig (remove the write protection) and download it. Rather than doing Know_How_Protect (which would mean that the end customer can't monitor Blocks anymore), youcould thereafter use the"Store Read only .." functionality to create "read only" versions of all manufacturers blocks (make sure to have a backup copy of all Blocks before you save them as a read only copy, the "Store Read only .."is available in later Step 7 versions from the File menu when a Block is open). This now means that the offline version of the individual read only saved Blocks can't be changed anymore,rather than having a PLC wide write protection(which is what I believe you want to achieve). NOTE: The end customer will now be able to use forcing and Variable Table related "writes" into the PLC (which is something he can't do if PLC wide "write protection" is set and the manufacturer mayobject to this). Food for thought anyway andI hope this helps Yes, thanks, that "Store Read only" looks quite interesting. I will definitively look into it. Thanks for your valuable input, Danke Petr
peva Posts: 38 Rating: (0)
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This contribution was helpful to 1 thankful Users fritz

4/28/2016 7:33 AM	Rate (0)
vipz Gold Member Joined: 9/2/2012 Last visit: 4/29/2023 Posts: 711 Rating: (30)	Dear Fritz, its very old post, but very useful... Now only i come to know, we have option like this in STEP7 !!! is any option to do the same for hardware configuration ?
	With Best Regards VIPZ
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4/28/2016 7:47 AM	Rate (0)
ANKURGAMIT Silver Member Joined: 10/2/2013 Last visit: 5/16/2023 Posts: 339 Rating: (51)	vipz Dear Fritz, its very old post, but very useful... Now only i come to know, we have option like this in STEP7 !!! is any option to do the same for hardware configuration ? Sir, are you about Know_How_Protect ? Or other ?
	PROBLEMS ARE OUR ASSEMBLY POINTS. SO WE THANKS TO PROBLEMS.
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4/28/2016 7:55 AM	Rate (0)
Ibrahim Fathy Bronze Member Joined: 9/18/2013 Last visit: 5/9/2022 Posts: 203 Rating: (12)	vipz Dear Fritz, its very old post, but very useful... Now only i come to know, we have option like this in STEP7 !!! is any option to do the same for hardware configuration ? Hello, Do you mean "Store Read Only" for the hardware configuration?! I think what is available for Hardware configuration is the Protection settings set from CPU properties in HW config. Also if any changes is modified in HW config. it can be easily known (that changes are made) through SDB Dialog Box
	Last edited by: Ibrahim Fathy at: 4/28/2016 8:08:25 AM
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