Siemens Simatic PCS 7 Function Manual page 218

Failure, switchover and reintegration of high availability components
7.10 Guide to updating a redundant OS in runtime
Checking time synchronization
To avoid any jumps in time (UTC/local standard time) when "updating redundant systems in
runtime", check the time synchronization of the OS in the updated PCS 7 project on the ES:
1. Open SIMATIC Manager.
2. Select the OS in the component view.
3. Select the menu command Edit > Open Object.
WinCC Explorer opens.
4. Click the "Computer" object in the tree view.
5. Select the menu command Edit > Properties.
The "Computer Properties" dialog box opens.
6. Select the "Parameters" tab.
7. In the "PLC Clock Setting" group, activate the "PLC is set to coordinated universal time
(UTC)" check box.
Objectives of the update
● The automation system remains uninterrupted in RUN mode.
● The process remains controllable at all times.
Sequence of the Update
Updating involves five phases:
Phase
Phase 1
Phase 2
Phase 3
Phase 4
Phase 5
218
Action
Updating Server_2 (Page 224)
Updating the OS clients interconnected with Server_2 (Page 227)
Downloading the connections, gateways and changes to the AS (Page 229)
Updating the OS clients interconnected with Server_1 (Page 230)
Updating Server_1 (Page 232)
High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA