Hello. There is a problem in the formation of WinCC graphs over time begins to "tighten" the testimony. Those. The graph displays readings offset more than 15 minutes. After restarting WinCC offset "zeroed" and eventually begins to grow.
The system - windows server 2012, WinCC V7.3, Intel core i3, 4 GB of RAM.
The controller's time is synchronized with the NTP on the system.

For example:
There are indications that reset on change - at 8.00, 16.00 and 00.00.
The graph clearly shows how the displacement increases with time.
In what may be the problem exists?

Screenshots in attachments

Regards!
 

Hello,

you should create a Service Request for the Technical Support.