Hello,

I have a project running in WinCC Professional v15.1 Update 5.

It has been running for a while on site, and they have asked me to add new variables to the historical data. In order to keep things tidy, I have a few Data Logs, each corresponding to one of the subsystems of the plant.

The problem is that when I add a new Logging Tag to one of the existing Data Logs the data is not actually logged. The new tag can be found and added to a trend view window, but there is not data being displayed

If I add a new Data Log with the new tag, or if I completely delete and then re-create a Data Log adding the new Logging Tag, it works fine.

But I don´t want to be adding new Data Logs every time they ask for a new variable, and I'm afraid that deleting a Data Log and recreating it with the new tags added, will mess with the existing historical data and won´t be able to retrieve the older data

Does anyone know why this happens, and how could I fix it? Should I overwrite data when loading the new project? Will this affect my older logs?

Thanks in advance,

Gonzalo

Hi gniski,

Perhaps the database has not been dimensioned correctly for the Tag Loggin.

What is the maximum Logging time (months, weeks, etc.)? And the maximum size of each segment?

Perhaps a screenshot of this configuration section in the project will help.

Hello itafusna,

As far as I can tell, those are not limitations in WinCC Professional. Or at least, I can´t find that information. Do you know where would that be?

Hi again,

I don't know if it is documented, I haven't found it either. But I understand that the following must be fulfilled, both for WinCC 7.X and WinCC Professional, in the Tag Loggin configuration:

- Total size of the segments, maximum 6 months.

- Total sum of segments in ArchiveManager (Alarm Logging + Tag Logging (Fast + Slow)) not exceeding 200 segments.

-Each segment no more than 2GB.

Also, if you want log data for more than 1 year, the additional Process Historian tool would be needed.

Hi,

thanks to both for the answers. I clearly don´t know enough about this to answer right away, so I'll check the FAQ to see if I can get that information.

However, it doesn´t seem to be a limit problem, because if I add a new Data Log, I can add the new logging tag, and many more, and they work perfectly fine. The problem seems to only happen when I try to add a new Logging Tag to an existing Data Log. The "old" tags are still being logged but the new one isn´t. But if I add a new Data Log, then I can have the "old" plus the new, all working fine

Can you think of something else that may be causing the issue? Could it be that I need to perform a full load, with overwriting everything, instead of a delta load?

Thanks,
Gonzalo