No Connection To Data Server! WinCC

Hi All, 

I would like to share a weird experience i have on this " No Connection To Data Server "Topic.

Case Study

1. The system is PCS 7 V8.0 Up1, Windows Server 2003. 

2. Both OS Servers （Master and standby) was running good. 

3. OS_B runtime deactivated manually, but unable to complete deactivation. 

4. Used reset_wincc to kill the process and do something. 

5. restart and try start up, OS project is not responding , stuck at Autostart. Project cannot be opened. 

6. restart the system and cancel the autostart. Download OS Project WinCCAppl_Stby from ES. Executed successfully. 

7. restart OS_B. Autostart successfully. But when the OS_B activated and go into runtime, alarm one line showed "No Connection to Data Server" . 

8. after 30 seconds , force restart windows popped out , " An error has occurred that requires a restart of computer" (seem like a simatic net issue)

9. After checking around, Terminal Bus adapter was disabled. 

10. Restarted and check the Ping, simatic shell, station configuration , the result are all the same. No connection to data server. 

11. Since the OS_A is running and the production cannot be stopped, i have no choice but to continue at next available chance. 

12. I shutdown the OS_B station for a night, and restart the second day. 

13. OS_B booted into runtime without issue. 

Weird experiences. At the end, my solution is, download the OS project again, and "SHUTDOWN" , then start it again. Hope it is helpful for someone in the future. 

For other related topics, please refer below: 

1. No Connection to data server - 20200811

2. No connection to data server - 20171201

3. WinCC Alarm Logging - 20140820

4. No Connection to data server - 20140827

5. No Connection to data server - 20150907