Hi,

I have Wincc7.2 and with Trend page but there is no connection with database (icon with little pc is red), and the error  Message is "Tag invalid or No connection to database"

I have tried to copy the project in another system with the same PLC and same HMI, same model and same OS Windows 7 64bit,  and It works fine.

I have done again installation of WINCC but same problem, Could be some Windows option that I need to check? There is some SQL option that I need to check?

What could be the problem? Thanks in advance

Hi giuseppepa,

Pleas check following points
1.If you System is a client server system please check follow point.

Why does the message "No connection to the data server" appear on the client in Alarm Logging / Tag Logging OCX?
https://support.industry.siemens.com/cs/ww/en/view/16720071

2.Pleas check the Quality Code of the Tag.
Stop the Runtime and reset the Tag Logging
As from SIMATIC WinCC V6.2, how can you delete the Runtime data of the Alarm Logging and Tag Logging?
https://support.industry.siemens.com/cs/ww/en/view/17853608

3 Stop the Runtime an close the WinCC Explorer.
Delete the dcf file in the project folder
Why will the WinCC project runtime not start?
https://support.industry.siemens.com/cs/ww/en/view/26134056

Best regards

schufri