Open a graphics, all the objects' value display normally, when there is a power cycle on the controller which the objects resided., the graphics will not poll the objects' value, unless reopen the graphics or move to design mode then go back to run mode.
SQL express 2005 + Windows 7
SQL server 2008 R2 +Windows server 2008 SP2
- Controller is in a heavily workload condition, the scan value reaches to high value
- Write value to the point under another controller but the controller is offline or there is some communication failure, although the scan is low but the program not work
- Delete or disable the program
- Modify the program to make sure the scan value is not greater than 1