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Problem with download of retained tags


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I have a project written in version 1.25.560 that I have renamed an upgraded to 1.35.227.

The program upgraded OK but when I try to download the retained tags from my old project i get the message below.

My program include  lots of parameters that is carefully tuned and I want to avoid  to do this tuning again.

Any suggestions on how I may solve this?




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Did you already download the project to the PLC?

If so, the retained tag should have their valid values before you've upgraded it. Is that the case?


If so, then there is no need to download the retained tags memory again, but I would upload the retained tags from the PLC again. 

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I have upgraded and downloaded the project, but then all the retained tags are set with their default value.

Is it a possibility to update the default values of the retained tags with the actual values in the PLC before I upgrade?

Previously (before upgrade) I have always used the function "Upload PLC retained memory to PC". This saves the values of the retain memory as a file. 

Then, in the new project I first have to download the PLC program, then I download the retained tags from this file to get my parameters correctly copied from the old project.

This has worked fine previously, but after I upgraded the software version I am no longer able to do copy the retained tags from the old to the new PLS in this way.

Do You have any other solutions to this?


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I'm not sure what your retained tags contain (Which tags and which structs). There is a chance that the upgrade caused the address of some retain tags to change (due to some retained tag that were of type of Reserved Structs that were changed from version 1.25 to 1.35), so in this case copying the values from the original project to original (old) address would be wrong, since the address is not correct.


You can send me the original project (in version 1.25), and the Retained tags file, and I will look into it.

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Actually, a function i have missed in Unilogic is the possibillity to update the default value in tags from the running program. Typically this would be useful for all parameters that is adjusted from the HMI-panel during commisioning, eg. controller parameters, I/O scaling etc. This will reduce the risk of problems later, typically if the battery backup fails.

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If I understand you correctly, you want to change the Initial Value of retained tags from the PLC, right?

(Initial value of a retained tag is the value it gets when you download the program on the first time, or you call Init retained tags). In this case, the values are compiled into machine code, so it's not possible.

If you want to just change values of retained tags, then you can create HMI screens for it, and maybe also edit the values from the UniApps (I need to check if it's possible, but even if can be done, then it's very uncomfortable because it was not meant for it)

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Yes, you understand me correct.

I have missed a function where i read the actual value for all (or selected) retained tags into the initial value. Then compile the code with this new values.

In Siemens there is a possibility to write both initial and actual values to Excel-sheets and then compare and copy actual values with the initial values.

But I have not found any similar function in Unistream. In my program I have a lot of parameters that I "tune" during commisioning, and now they are only stored with battery. This I do not feel as safe as having them as compiled code. And I am to lazy to copy by hand... 🙂

Also it would have solved my version-problem which i started this discussion with since I could have updated the initial values in the old project before upgrading.    


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