Validating Engineering Standards and Commissioning Multi-Client Mode Across Multiple Projects

To successfully commission Multi-Client mode across multiple PCS 7 projects in a large plant, adhere to the definitive six-step Siemens engineering standard: establish a unified Terminal Bus with synchronized NTP system clocks, ensure uniform Windows user accounts and 'SIMATIC HMI' group permissions across all stations, generate and export server data (.pck) from each independent OS Server, import all server packages into the OS Client project, assign standard servers for Alarms and Split Screen Manager, and execute the OS Project Editor on the client.

Executive Summary

In large continuous manufacturing and processing facilities, the automation topology frequently spans multiple discrete SIMATIC PCS 7 (V8.0 through V9.1) multiprojects (e.g. Raw Material Handling, Polymerization Units, and Utilities). Centralized operations require multi-client operator stations capable of seamlessly supervising process units across all projects. Commissioning attempts frequently fail due to incomplete validation checklists, desynchronized clocks, and network security misconfigurations. This article provides a comprehensive, verified engineering validation standard for commissioning multi-client architectures across multiple multiprojects.

Architecture and Fundamental Mechanics

Multi-Project Multi-Client Integration Architecture and Engineering Standards:

Multi-Project Network Topology:
Multiple independent PCS 7 Multiprojects (Project A, Project B, Project C) share a common physical or routed Terminal Bus network.
Each multiproject operates its own autonomous AS controllers, redundant OS Server pairs, and local Engineering Stations.
Centralized OS Clients are hosted within one designated 'Master Client Multiproject' (or within one of the primary project containers).
Core Validation Pillars for Multi-Project Integration:
1. Time Synchronization Standard:
- All OS Servers, OS Clients, and AS controllers across all multiprojects must synchronize to a single central GPS/NTP master clock (e.g. SICLOCK TC400 or corporate domain time server).
- Time divergence $> 1000\text{ ms}$ between servers and clients corrupts WinCC alarm logging sequence stamps and causes server package rejection.
  2. Security and Name Resolution Standard:
- Forward and reverse DNS hostname resolution must resolve over the Terminal Bus for all participating nodes.
- In domain networks, all stations must join the same Active Directory domain. In workgroup networks, identical Windows usernames and passwords must exist on every station, and all accounts must belong to the local SIMATIC HMI group.
  3. Package Export and Loading Standard:
- Each OS Server compiles its local tag and alarm configuration, exporting a self-contained server package (.pck).
- The OS Client loads packages from all servers, aggregating disparate plant units into a single consolidated runtime interface.
  4. Standard Server Assignment Standard:
- Because multiple servers exist, the client must explicitly declare which server manages default alarms and Split Screen Manager (SSM) coordinate layouts.

Step-by-Step Implementation Procedure

Step-by-Step Commissioning Procedure for Multi-Project Multi-Client Systems:

Validate Network Infrastructure and Time Synchronization:
- Verify that all OS Servers and OS Clients can ping each other across the Terminal Bus using both IP address and computer hostname.
- Configure all stations to synchronize time via NTP to the central plant master clock; confirm time offsets are $< 100\text{ ms}$.
Establish Security and User Authentication:
- On every OS Server and OS Client machine, open Computer Management -> Local Users and Groups.
- Confirm the active operator user is a member of the SIMATIC HMI and local Administrators groups.
- Run the Siemens Security Controller on all nodes to apply standard Windows Firewall and DCOM communication exceptions.
Generate Server Data in Each Multiproject:
- Open Multiproject 1 in SIMATIC Manager on ES 1.
- Open the OS Server project; in Component View, right-click the OS Server object -> select Server Data -> Generate.
- Repeat this procedure for Multiproject 2 on ES 2.
- Export the generated .pck files to a shared engineering network staging folder.
Import Server Packages into the OS Client Project:
- Open the multiproject hosting the OS Client in SIMATIC Manager.
- Open the OS Client project.
- In Component View, navigate to Server Data -> right-click Server Data -> Load....
- Select and import the .pck file from Multiproject 1.
- Repeat Load... to import the .pck file from Multiproject 2.
Assign Standard Server and Split Screen Manager (SSM):
- In the OS Client project, right-click Server Data -> Standard Server....
- In the Standard Server dialog, assign the primary OS Server for Alarms and SSM.
Execute OS Project Editor and Download Client:
- In the OS Client project, double-click OS Project Editor -> select the multi-monitor or single-monitor layout -> click OK.
- Download the OS Client project to the physical client workstation.
- Activate WinCC Runtime on the client.

Verification

Verification Procedure:
1. Server State Verification: On the OS Client, open the 'States of Connected Servers' window (@ServerState.pdl). Confirm that all servers from Multiproject 1 and Multiproject 2 display green checkmarks with status 'Online'.
2. Cross-Project Process Navigation: Click picture navigation buttons for Unit 1 (Project 1) and Unit 2 (Project 2). Confirm that graphics load promptly and dynamic analog/digital tags update smoothly.
3. Unified Alarm List Audit: Trigger an alarm in Project 1 and an alarm in Project 2. Confirm that both alarms appear simultaneously in the OS Client's consolidated WinCC Alarm Journal.

Limitations and Operational Precautions

Operational Precautions and System Boundaries:
- Architectural Limits: Respect official Siemens maximum system limits: an OS Client can connect to a maximum of 18 OS Server pairs, and up to 64 OS Clients can access a server pair.
- Picture Naming Discipline: Maintain a unified, plant-wide naming convention; never use identical graphic picture (.pdl) names across different multiprojects.
- Commercial and Licensing Boundaries: Each physical client workstation requires exactly one OS Software Client runtime license, and each server pair requires appropriate OS Software Server Redundancy and OS RT PO licenses. Validate all quantities against the official Siemens ST PCS 7 catalog and an authorized distributor quotation.

Engineer FAQ

Can an OS Client display data from two different PCS 7 multiprojects?

Yes. By generating server data in each multiproject and loading both server packages into the OS Client project, the client can seamlessly supervise both projects.

What is the most critical network requirement for multi-project integration?

A unified, low-latency Terminal Bus with synchronized NTP master clocks and bidirectional NetBIOS/DNS hostname resolution across all nodes.

How many OS Server pairs can a single OS Client connect to?

In PCS 7 V9.0 and V9.1, an OS Client can connect to up to 18 OS Server pairs simultaneously.

Why is configuring a 'Standard Server' necessary on an OS Client?

The Standard Server defines which server manages default alarm logging and Split Screen Manager window geometry when multi-server packages are active.