Siemens SIMATIC PCS 7 Function Manual page 209

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
Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA
Failure, Switchover and Return of Fault-tolerant Components
6.10 Guidelines for updating a redundant OS in runtime
Action
Updating Server_2 (Page 214)
Updating the OS clients interconnected with Server_2 (Page 217)
Downloading the connections, gateways and changes to the AS (Page 219)
Updating the OS clients interconnected with Server_1 (Page 220)
Updating Server_1 (Page 222)
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