Consolidating Multiple WinCC Projects into One Master Project

1. Overview: The WinCC Consolidation Problem

Operators running a multi-line plant frequently inherit a portfolio of stand-alone HMI/SCADA stations. Each station is delivered as its own SIMATIC project with its own PLC (S7-200, S7-300, or S7-400) and its own WinCC HMI/SCADA application. When a control room consolidation project is initiated, the engineer is asked to bring all process screens, alarms, archives, and tag databases under a single supervisory application.

Siemens WinCC does not provide a native "Merge Project" command. Whether the runtime is WinCC 7, WinCC Professional (TIA Portal), or WinCC Unified (TIA Portal), you must consolidate projects by importing the engineering objects from each subordinate project into a single master project. This document covers the import strategy, the loss of "integrated" AS-OS coupling for S7-200/300/400, and the multi-device loading pattern available in TIA Portal V20 for WinCC Unified PC RT.

2. Prerequisites

Before beginning the consolidation, verify the following engineering preconditions:

• Source projects must be exportable. In WinCC 7.x, the project must be opened in WinCC Explorer; in TIA Portal, the project file (.ap20 for V20, .ap17 for V17, .ap16 for V16) must open without conversion errors.
• All source PC stations must run a WinCC version compatible with the master project. Mixed WinCC 7.0 / 7.4 / 7.5 sources, for example, must first be migrated to a common service pack.
• The master PC station must meet the WinCC installation requirements for the total tag count after import. WinCC 7.5 supports 256 power tags per server by default and up to 102,400 with the ASIA / 8K/64K/256K power-packs. Plan license counts before consolidation.
• Source S7 projects must be in STEP 7 V5.5 / V5.6 (for classic WinCC) or TIA Portal V16/V17/V18/V19/V20 (for WinCC Professional / Unified). S7-200 requires either STEP 7 Micro/WIN V4.0 SP9 or migration to a S7-200 SMART for inclusion in a TIA project.
• Backup of every source project (full .zip export of the WinCC project directory and the STEP 7 S7 program archive .s7p/.s7l) is mandatory before any copy operation.

3. Architecture Decision: Integrated vs. Non-Integrated AS-OS Coupling

Source projects fall into one of two categories, and the consolidation procedure differs for each.

The S7-200 driver channel is special: S7-200 CPUs communicate over PPI/MPI/TCP using the SIMATIC S7-200 PC Access OPC server, not the native WinCC S7 channel. When consolidating, install and register S7-200 PC Access on the master PC and configure an OPC DA channel in the master WinCC project pointing to OPC.S7200PCAccess.

4. Component-by-Component Import Procedure

The WinCC project database stores the following engineering objects. Each must be migrated individually because WinCC does not provide a project-level merge.

4.1 Pictures (Graphics Designer / PDL / Screen)

WinCC 7 uses .pdl files in the project GraCS/ directory. To migrate:

1. Open the source WinCC Explorer and select Graphics Designer.
2. Export each picture: File > Export > PDL to PDL or copy *.pdl from <ProjectPath>\GraCS\.
3. In the master project, copy the .pdl files into <MasterProjectPath>\GraCS\. WinCC detects new pictures on next start of Graphics Designer.
4. For TIA Portal Unified screens, use Project tree > HMI > Screens > Export/Import as .xml exchange format. Imported screens are re-numbered; rename the screen object to preserve any script references.

4.2 Tags and Tag Connections

Tag import is the most error-prone part of consolidation because tag addresses collide between PLCs that share a common address range.

Use the following CSV column template for WinCC 7 classic import (UTF-8 encoded, comma-delimited, header row required):

Example row for a discrete input from an S7-300 on MPI address 2:

4.3 Messages (Alarm Logging)

Message consolidation in WinCC 7 must preserve the message number range and the message class structure. Use:

1. Alarm Logging > Tools > Export > CSV on the source project.
2. Open the exported CSV in Excel; concatenate all source CSVs vertically.
3. Reassign message numbers in 1000-block ranges per source area to avoid duplicates (e.g., source A uses 1-999, source B uses 1001-1999, source C uses 2001-2999).
4. Import the combined CSV into the master project's Alarm Logging editor.

4.4 Tag Logging and Archives

Tag Logging archives migrate through three steps:

1. Export the archive configuration (tag selection, acquisition cycle, archiving cycle, archive name) from each source project via Tag Logging > Tools > Export.
2. Recreate the archive layout in the master project using the same parameters.
3. Use the WinCC CCArchiveImportTool.exe utility (located in <WinCCInstall>\bin\) to import historical segment files (*.lrf) from the source archive directories (<ProjectPath>\ArchiveManager\) into the master archive path.

4.5 Reports and Print Jobs

Copy *.rpl report layouts from each source project's PrintJobs/ directory into the master. Re-link report connections to the new (master) tag names using the Layout Designer. Print jobs themselves are stored in the WinCC project database and must be re-defined in Report Designer > Print Jobs.

4.6 Global Scripts (C / VBS)

WinCC 7 C and VBS scripts are stored in the project database, not as files. To consolidate:

1. Open the source project in WinCC Explorer.
2. Right-click each action or function in Global Script > Export.
3. In the master project, right-click Global Script > Import and load each .pas (C) or .vbs (VBS) file.

Search every script for hard-coded tag names that must be updated to the new master tag names. Use the Global Script editor's "Find" function to batch-rename references.

5. Building the Master Navigation Picture

After all subordinate pictures are imported, build a start picture in the master project that exposes one button per consolidated area. The simplest mechanism is a button with the following C action (WinCC 7):

For VBS on WinCC 7 or WinCC Unified:

Place a Screen Window object on the master start picture and assign each area button to change the Screen property. This avoids the performance penalty of opening multiple GraphIC Designer instances.

6. User Administration Consolidation

Each source project may carry its own User Administrator database. If the access levels differ between projects (e.g., Line 1 uses 0-5, Line 2 uses 0-7), you must reconcile them.

Re-authorize each user's level mapping per area. Use WinCC's Authorization property on each operator input object to gate specific actions, e.g., Level 1 (Lead Operator) required for Line1 setpoint write.

7. Connection and Channel Configuration

Each source PLC requires its own logical connection in the master project. Avoid sharing one S7 connection across multiple PLCs — Siemens recommends one connection per CPU for diagnostic clarity.

Connection timeout parameters should follow the master project's policy; do not retain the per-source values, as they reflect individual network characteristics that may differ in the consolidated plant.

8. Multi-Device Loading in WinCC Unified (TIA Portal V20)

If the consolidation target is not a single PC but a coordinated multi-station operator floor, TIA Portal V20 provides a multi-HMI load mechanism for WinCC Unified PC RT. The procedure is documented in the TIA Portal Help for V20.

1. In the TIA project tree, multi-select the WinCC Unified PC devices: hold Ctrl and click each PC RT node under Devices & networks.
2. Open the toolbar and click Load. The "Load preview" dialog shows the changes for every selected device in a single view.
3. Confirm the load to push the consolidated engineering data to all selected PC RT stations simultaneously.
4. Verify on each PC that the WinCC Unified RT runtime has entered Running state and the operator start picture is displayed.

Reference: TIA Portal Help V20 > Compiling and loading RT Unified > WinCC Unified PC RT Unified > Downloading projects (RT Unified) > Loading projects of multiple HMI devices simultaneously (RT Unified) (see the official TIA Portal V20 documentation).

9. Recipe and Data Record Handling

WinCC 7 Recipes (or WinCC Unified Recipes in TIA V17+) are stored per project. When consolidating:

1. Export each source recipe as *.csv via Recipe Editor > File > Export.
2. In the master, create one recipe per source area, preserving the original element names where possible.
3. Recreate recipe views on the master start picture, grouped per area, so operators see the recipe tree relevant to their line.

10. Verification Procedure

After consolidation and before cutting the master over to production:

1. Compile check — In TIA Portal, run Project tree > master project > Compile > Software (rebuild all). In WinCC 7, use the Status dialog in the project properties; resolve every error and warning.
2. Tag connection test — In WinCC 7 Tag Management, right-click each connection and select Status. The Quality Code must be 0xC0 (Good). For OPC connections, use the OPC Scout to verify the server returns live data.
3. Alarm simulation — Trigger each imported message class in test mode; verify the text and acknowledge behavior in the master message list.
4. Archive round-trip — Force a tag to change value, wait one archive cycle, export the archive segment, and confirm the timestamp and value are recorded.
5. User authorization test — Log in as each role (0 through 5) and verify that operator inputs are gated correctly per the matrix in Table 3.
6. Load test — In WinCC 7, use Server Tasks > Performance to monitor tag polling and alarm throughput. A consolidated project should not exceed 70% of the license tag count at peak loading.

11. Troubleshooting Matrix

12. Long-Term Maintenance Recommendations

• Establish a naming convention for all future WinCC projects: prefix every tag, picture, archive, and message with the area code (e.g., AREA_TAGNAME) to prevent collisions when re-consolidating.
• Use a central SIMATIC Logon server for all user administration so that consolidation does not require user re-creation.
• Maintain a project functional specification that documents the loss of AS-OS compile coupling (for S7-300/400 classic configurations) and the CSV import pattern used in its place.
• Schedule quarterly archive backups using WinCC's Configuration > Archive Backup to limit exposure to data loss during future re-consolidations.
• For new projects, prefer WinCC Unified PC RT (TIA Portal V17+) and the multi-device load pattern described in Section 8, which avoids many of the manual import steps above.