How to Synchronize PCS 7 V8.2 Automation and Operator Stations

To synchronize AS1, AS2 and both PCS 7 V8.2 OS servers, configure one coherent time architecture and assign each station a master or slave role supported by its hardware and network. Siemens documents both central-clock and cooperative OS-server designs, but the exact AS settings vary by CPU, communications processor and bus topology. Because those details are not given here, select the matching V8.2 configuration before changing a running plant.

Select One Time-Synchronization Architecture

First choose a single, documented time architecture that fits the actual network and AS hardware. PCS 7 V8.2 supports plant designs using a central plant clock and designs using OS servers as cooperative time masters. Avoid configuring separate independent masters on the same synchronization stratum: Siemens defines one active master per stratum. The source question does not specify CPU models, CPs, network topology, domain/workgroup, or an installed central clock, so those details must be checked before choosing the branch.

An external central clock is the clearest common reference where available. In Siemens' V8.2 example, SICLOCK distributes time on the plant and terminal buses; OS clients obtain time frames from an OS server. In a workgroup without a central clock, Siemens documents cooperative OS-server masters and AS devices configured as slaves, subject to hardware constraints.

Configure OS Servers for the Chosen Design

For a V8.2 workgroup design with central SICLOCK, the manual's OS-server procedure is:

In the PCS 7 project on the engineering station, open the OS server.
In WinCC Explorer, open the Time synchronization editor.
Enable Synchronization via System Bus (Master, Slave) and Display symbolic name of the access points.
Select the appropriate network adapter under Access point 1 and select Master as required for the documented cooperative-master arrangement. Configure a redundant access point only if the station and communications processor support it.
Apply and download/activate the configuration using the site's approved PCS 7 change procedure.

The manual lists OS server communications-processor requirements: CP 16x3/16x8 in specified larger or fault-tolerant configurations, or BCE/Softnet up to eight AS; BCE/Softnet cannot be configured redundantly. The exact applicable processor and network settings must match the hardware.

Configure AS Devices as Time Slaves

For the documented V8.2 example using a central clock with S7-400 modules, time synchronization is configured in HW Config. One illustrated configuration uses a CP 443-1 to receive plant-bus time and distribute it on the C bus, with the CPU and CP 443-5 Ext receiving it as slaves. The manual's example then configures the CPU's Diagnostics/Clock synchronization mode as As slave and, for its specified CP 443-5DX05 fieldbus path, selects From station to LAN. These settings are specific to that example's modules and bus arrangement; do not copy them to a different CPU or CP without checking its applicable table in the V8.2 manual.

The OS-server-to-AS option in the ticket is therefore not a generic setting sequence. Select its direction and forwarding path from the actual AS communications hardware and Siemens' matching V8.2 configuration figure. Some CPU families or integrated interfaces support only NTP; the manual notes restrictions where SIMATIC-mode cooperative OS masters are used.

Use a Consistent Time Basis

Choose and apply a time basis appropriate to the plant. The ticket reply suggests UTC for the PLC and local time display on the OS, but Siemens' manual covers time-zone and UTC behavior in more detail; the correct setup depends on the architecture. Keep the underlying synchronization method and displayed time-zone conversion distinct. Ensure Windows domain policies or other time services do not compete with the PCS 7 time-synchronization method. The V8.2 manual explicitly warns against using multiple synchronization methods simultaneously on PC stations configured for its NTP procedure.

Expected Results and Verification

Verify every layer independently: the active time source, OS-server synchronization status, AS time status, and the displayed event timestamps. Siemens' V8.2 manual includes checks for PC stations, communications processors, and the OS server's time-master role. Check that AS1, AS2, OS Server 1 and OS Server 2 converge on the intended reference and that the selected OS time-zone display is understood. A successful project download alone does not prove that all nodes receive frames on the intended network.

Limitations and Operational Precautions

Exact settings depend on CPU model, firmware, communications processors, bus topology, redundant configuration and workgroup/domain design. The source does not provide these data; use the corresponding Siemens V8.2 configuration branch before changing a running plant. Time corrections can affect event chronology: Siemens documents that a deviation greater than ±5 seconds causes an immediate clock reset in the described synchronization response, and warns that data sent before and after the reset can have non-monotonic timestamps. Plan changes with operations, preserve the current configuration, and verify event logging after controlled implementation.

Verification

Record the chosen master and path for each segment, then inspect the synchronization status and clocks at AS1, AS2, both OS servers and any client. Compare timestamps over a controlled interval using a common reference and confirm the OS display time zone. If stations disagree, check frame reception, selected network adapters, whether another time service is active, and whether the configured CPU/CP supports the selected mode.

Engineer FAQ

Should the PLC or OS server be the master? PCS 7 V8.2 documents multiple architectures. Select one based on the central time source, buses and supported AS hardware; do not assume either direction is universal.

Can two OS servers both be configured as masters? In Siemens' cooperative design, OS servers may be configured as cooperative masters; the first active one not receiving another master's frame assumes active-master operation, while peers become slaves.

Can I use SIMATIC time synchronization across routed networks? No. Siemens describes SIMATIC mode as MAC-address-based Layer 2 communication that is not routing-capable.

Does the ticket establish the correct settings for my AS? No. CPU and CP types are missing, and the manual's settings differ among hardware configurations.

Is the OS display necessarily in UTC? Not necessarily. The synchronization basis and the OS's local-time display and daylight-saving configuration are separate considerations.

Technical References

Siemens, Time Synchronization (V8.2), Function Manual, 03/2016, A5E36200246-AA, Sections 3.7–3.8, 6.4 and 6.6 (operating principles, architectures, OS servers and AS configurations): https://cache.industry.siemens.com/dl/files/963/109485963/att_878545/v1/ps7tsy_b_en-US.pdf

How to Synchronize PCS 7 V8.2 Automation and Operator Stations