Cross-Multiproject OS Client Architecture in SIMATIC PCS 7: Configuring Multi-Project Server Data Import and WinCC Picture Access

To display WinCC process screens and HMI data from one SIMATIC PCS 7 project on the OS Clients or Servers of another project, configure a cross-multiproject multi-client architecture. First, ensure both multiprojects share a common physical or routed Terminal Bus network with synchronized Windows domain workgroups and identical SimaticRights. In the source engineering station, compile the source OS Server to generate its Server Data package (.pdk). Copy or import this server data package into the destination OS project. Assign the imported package to the destination OS Clients. The OS Clients can then access pictures, alarms, and tags across both multiprojects simultaneously.

Cross-Multiproject HMI Integration Challenges in Large Plants

In extensive industrial facilities, automation architectures are frequently segregated into separate SIMATIC PCS 7 multiprojects. For example, a chemical facility may manage the utilities plant in Project A and the process units in Project B. Operational requirements often mandate centralized supervisory control where an operator sitting at a single OS Client station must view process mimics, acknowledge alarms, and operate drives originating from both multiprojects.

Because each PCS 7 multiproject maintains its own engineering database, Component View, and Plant Hierarchy, an OS Client cannot be directly assigned to OS Servers outside its host multiproject using standard local assignment dialogs. To overcome this boundary, PCS 7 provides the cross-multiproject Server Data export/import mechanism.

Network Prerequisites and Terminal Bus Architecture

Before configuring software packages across multiprojects, verify the underlying infrastructure:

Terminal Bus Connectivity: All OS Servers, OS Clients, and Engineering Stations must be reachable over the Terminal Bus. Subnet masks, default gateways, and DNS/WINS name resolution must operate seamlessly without blocked ports (especially TCP 135, TCP 445, and WinCC communication ports TCP 102 and TCP 1433/1434).
Security and SimaticRights: All stations should belong to the same Windows Active Directory Domain or identical workgroup with mirrored local Windows accounts and identical passwords. Users must belong to the SIMATIC HMI and SIMATIC NET local groups on all nodes.
SIMATIC Shell Encryption: If encrypted communications are enabled in SIMATIC Shell, both multiproject stations must share the identical PSK (Pre-Shared Key) certificate settings.

Exporting Server Data Packages (.pdk) from the Source Multiproject

The source OS Server generates a binary metadata package containing tag prefixes, tag names, alarm archives, and picture names:

In SIMATIC Manager on the Source ES, right-click the OS Server object and select Compile OS.
Perform a complete compilation of the OS Server.
In WinCC Explorer on the Source OS Server, right-click Server Data and select Create.
WinCC generates the server package file <OS_Name>.pdk in the project subfolder \wincproj\<OS_Name>\Packages\.
Copy this .pdk file across the network share or via removable storage to the destination Engineering Station.

Importing and Assigning Server Data in the Destination Project

On the destination Engineering Station:

Open the destination multiproject in SIMATIC Manager.
Open the WinCC project of the destination OS Client (or destination OS Server if performing server-to-server linking).
In WinCC Explorer, expand the project tree, right-click Server Data, and select Load.
Browse to the directory containing the copied source <OS_Name>.pdk and complete the import.
In SIMATIC Manager, right-click the destination OS Client, open Assign OS Server, and verify that the external server package is checked.
Configure the Standard Server settings if split alarm or archive logging is required across project boundaries.

Cross-Project Picture Navigation and Standard Picture Transfer

When an OS Client opens a picture belonging to an external server, WinCC utilizes the syntax <Package_Prefix>::<Picture_Name>.PDL:

Picture Tree Integration: If picture tree hierarchy from both multiprojects is desired on the client, the Picture Tree manager can incorporate nodes referencing the foreign package prefix.
Screen Scripting: In C-Action or VBS scripts, tag calls must explicitly include the server prefix if accessing tags outside the default server: GetTagDouble("SourceOS::TI_101.PV_Out").
APL Block Icons: APL block icons generated from the source project will automatically resolve their tag prefixes through the imported server data package, allowing faceplates to open transparently across project borders.

Cross-Multiproject Integration Architecture Matrix

The following table compares integration characteristics between standard single-project and cross-multiproject client configurations:

Architectural CharacteristicSingle Multiproject ClientCross-Multiproject MultiClientCross-Project Server LinkingServer Data GenerationAutomatic during OS CompileManual or Scripted PDK TransferManual Export/Import of PDKTerminal Bus RequirementSingle Local SubnetRouted Subnet with Full Name ResolutionRouted Subnet with High BandwidthSecurity AuthenticationLocal Domain / WorkgroupCross-Forest Trust or Identical AccountsSynchronized SIMATIC HMI Group UsersPicture SynchronizationIntegrated WinCC DownloadIndependent Picture Directory SyncWeb/Server Client Package QueryRedundancy SwitchingAutomatic via Redundancy Server DataFully Supported with Pair PDKsPartner Status Monitored via Internal TagsSIMATIC Shell DiscoveryAutomatic Multicast BroadcastDirected Multicast or Network BridgingBroadcast across Shared Adapter

Step-by-Step Procedure to Link OS Clients Across Two Multiprojects

Follow this engineering procedure to establish cross-project OS Client monitoring:

Compile Source OS: In Project A, execute full compilation of OS_SRV1.
Generate Server Data: In WinCC Explorer of OS_SRV1, right-click Server Data -> Create. Verify the generation of OS_SRV1.pdk.
Establish Shared Transfer Path: Share a designated folder on the Project B ES or copy OS_SRV1.pdk directly to the Project B ES local disk.
Load Package in Project B OS Client: Open WinCC Explorer for OS_CLI_01 in Project B. Right-click Server Data -> Load, and select OS_SRV1.pdk.
Configure Default / Standard Servers: In Project B WinCC Explorer, right-click Server Data -> Standard Server. Designate which server handles Alarms, User Archive, and Split Screen Manager if unified handling is desired.
Verify Picture Pathing: Copy any custom project-specific PDL graphics from Project A's GraCS directory to the Project B Client GraCS folder if local client caching is utilized, or ensure OS Clients load graphics dynamically from server shares.
Download Client: In SIMATIC Manager Project B, perform an OS Download (Changes or Entire) to target station OS_CLI_01.
Runtime Validation: Start WinCC Runtime on OS_CLI_01. Open process mimics from Project A and Project B, verifying live tag updates and faceplate operation.

Verification

Validate cross-multiproject operations using these diagnostic steps:

Check Server Data Status: In WinCC Explorer on the destination client, verify that the source server package appears under Server Data with a green or valid loaded indicator.
Check Tag Logging and Online Values: Open WinCC Tag Management -> select the imported package prefix. Verify that external tags display live process values without quality code 0x00 (Bad Configuration) or 0x18 (Connection Failure).
Alarm Control Verification: Open the WinCC Alarm Control on the client. Verify that alarm events originating from AS controllers in Project A arrive in the client alarm journal alongside alarms from Project B.
Redundancy Switchover Test: If Project A utilizes redundant servers (OS_SRV1A and OS_SRV1B), temporarily disconnect the active server network cable and verify that the Project B client automatically switches to the standby server without process picture failure.

Limitations and Operational Precautions

Observe the following operational constraints when architecting cross-multiproject systems:

Package Refresh Lifecycle: Whenever tags, messages, or AS connections change in Project A, the server data must be regenerated in Project A and re-imported into Project B. There is no automated real-time cross-project push mechanism.
Maximum Server Data Limits: A WinCC OS Client supports up to a defined maximum number of simultaneously loaded server packages (consult the version-specific PCS 7 Plant Configuration Guide, typically 12 to 18 server pairs depending on PCS 7 release).
Time Synchronization: Both multiprojects must synchronize to a single Central NTP Time Master (such as SICLOCK TC 400). Time drift between servers causes inconsistent message sequencing and split-screen timestamp discrepancies.
Commercial Accuracy Disclaimer: Software order numbers (MLFBs), package structures, and hardware capacity prerequisites vary across PCS 7 versions and hardware platforms. System integrators must confirm exact software entitlements and licensing requirements against the official Siemens Catalog CA 01 and obtain an authorized Siemens distributor quotation prior to purchasing.

Engineer FAQ

Can an OS Client issue setpoints and control commands to controllers in the external multiproject?

Yes. As long as the operator has the appropriate WinCC user authorization levels (e.g., Higher Process Controlling) and the source project security settings permit client write commands, the client can operate APL faceplates and modify setpoints across both multiprojects.

What happens if the source OS Server is renamed?

Renaming the source OS Server invalidates all previously imported server data packages. You must regenerate the server data package under the new name, remove the obsolete package from the destination client, load the new package, and update any hardcoded picture scripts or tag prefixes.