When you create a new tag in WINCC TIA 15.1, the only way to specify a designation to this tag seems to enter this designation in the HMI comment field.  

For many reason, I would like to be able to get this designation at running time by script (C-script or VBScript). But it doesn't seem possible. Do you confirm ?

Else do you have any other suggestion to be able to associate a designation to a tag and than how to use it by script ?

Hello BruceBacc,

a similar discussion alread exists:
https://support.industry.siemens.com/tf//ww/en/posts/wincc-professional-hmi-tags-comment/150773?page=0&pageSize=10

I also know no simple way to achieve this.

But as a general approach to such situation I would go in this direction:
If I need some complex data, bound together, then I use a complex datatype.
In other words, make a struct or UDT and set up fields like "value" for the actual value information and "designation" for the designation information of this tag.
So you always have all the related information within one (complex) variable.

Could be a way. 

Let me hear your opinion.

Regards,

Nzett11

Thanks for your answer

We have already created UDTs for some useful "structured" equipment in PLC that contains many information : measuring unit, display pattern, tag display name, main and maxi range conversion". 
These sub-tags are directly used by WINCC for display. 
Indeed, we could have the possibility to add also a new "string" subtag in this UDT to contain complete designation. 

But not all the PLC tags are handled by this way.
Many of them are only BOOL tag and it will be too heavy to create a UDT for each of these tags in PLC. 

Really, it is a pity and it is surprising that is it not possible to get the 'Comment' field by script for that purpose. Any other SCADA system will allow to get tags designation. 

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Previoulsy, we had a database inside an excel sheet that generates automatically a CSV file imported manually in WINCC HMI tags list. 

This file contains two tags to describe one tag. Exemple : "MyPLCTag" and "MyPLCTag.Params"
- MyPLCTag is WINNC tag connected to PLKC tag.
- MyPLCTag.Params is an internal WINCC tag. Its initial value contains a string with useful fields separated by semicolon (designation, unit, IO address, curve limit, ...)

But the process was too heavy to handle each time we had an modification to integrate in WINCC (so that this excel sheet is always up to date) 
And now because we are using UDT, it becomes almost irrelevant since many WINCC tags and subtags are automatically created by drag&drop from PLC. UDT ... except for these many BOOL tags.


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To simplify the process, I think to following solutions :

1 - external file reading in memory
When RunTime starts (or when user presses a button in some kind of maintenance mode), I would like to :
- read once a file that contains a lot of lines containing a pair of 'TAG Name'='Tag Designation',
- put all these pairs in a global memory table in WINCC
- have a function in a script called f_get_tag_designation (s_tag_name) that search tag designation in this memory table

Unfortunately, I can find a solution to create such memory table by script by allocating memory dynamically. And I can't create a static memory table with two dimensions (for instance a_designations[<number of tags>][<designation buffer size)])  since this one is limited to 64 ko, which is not enough. 


2 - pi ssing lines in internal script :

function f_get_tag_designation (s_tag_name)
{
   if (strcmp (s_tag_name, "TOTO")==0) return "TOTO designation"
   else if (strcmp (s_tag_name, "TITI")==0) return "TITIdesignation"
   else
   .... 
   ...
   else return "????"
}

But this doesn't work if number ot tags to implement is important because script size is also limited. 
And this is not a very clean method. You need to modify WINCC script each time you want to make a designation change, then sending the archive to site, then...