Managing Windows Network Shares and S7Proj Folder Mappings in SIMATIC PCS 7

In SIMATIC PCS 7, local project folders stored in C:\Program Files (x86)\Siemens\Step7\S7Proj (such as Proj_1, Proj_2) often have different network share names (such as WinCC_Project_SRV_PM) across the Windows network. To identify which local directory corresponds to a given network share, open Windows Computer Management (compmgmt.msc), navigate to System Tools > Shared Folders > Shares, and view the mapping between Share Name and Folder Path. Never rename or reconfigure PCS 7 network shares manually in Windows, as WinCC OS Compile, Target OS Path resolution, and SIMATIC Shell rely on exact share definitions configured by the engineering system.

Network Sharing Architecture in SIMATIC PCS 7 Multi-Station Systems

In a distributed SIMATIC PCS 7 environment (comprising an Engineering Station 6ES7651-5AA58-0YA5, redundant OS Servers 6ES7652-0XX08-1XB0, and OS Clients 6ES7652-0CX08-1XB0), file sharing over the Windows terminal bus is fundamental. When an OS Server project is created or configured in SIMATIC Manager, the engineer specifies a Target OS and Master OS path. During project commissioning, PCS 7 automatically shares the project folder across the network so that the Engineering Station can execute Compile and Download OS and transfer runtime project packages.

By default, an OS project folder located locally on an OS Server PC at D:\WinCC_Projects\OS_SRV1\ is assigned a Windows network share name. This share name may be set to WinCC_Project_OS_SRV1 or a custom identifier designated during engineering. If an engineer accesses the Engineering Station or OS Server over Windows Explorer network neighborhood (\\ES_PC\), the displayed share names reflect Windows share names, not the underlying local folder names (e.g., Proj_1, Proj_2).

Windows Share Management vs PCS 7 Target OS Directory Mapping

The following matrix compares how directory paths, Windows shares, and PCS 7 internal mappings correspond in a multi-station plant:

Context / LevelLocation / InterfaceConfiguration EntityPurpose and Access RulesLocal FilesystemC:\...\Step7\S7Proj\Proj_1Windows DirectoryPhysical storage of Step 7 multiproject and AS hardware databases.OS Project StorageD:\WinCC_Projects\SRV_AWindows DirectoryPhysical storage of WinCC MCP project files, graphics, and SQL databases.Network Share\\SRV01\WinCC_Project_SRV_PMWindows Share NameNetwork endpoint used by ES during Compile and Download OS.SIMATIC ManagerOS Properties > Target OS and Master OSUNC Path MappingConfigures exact target share path (\\SRV01\WinCC_Project_SRV_PM).SIMATIC ShellNetwork Adapter SettingsBroadcast / Multicast BusTerminal bus interconnect resolving station names and redundancy pairing.Security ControllerWindows Security PoliciesSiemens Group PoliciesGrants SIMATIC HMI and SIMATIC NET user rights to shared folders.

Table 1: Directory mapping and network sharing entities across PCS 7 stations.

Inspecting and Verifying Share Mappings via Computer Management and PowerShell

To identify which physical directory corresponds to a specific Windows network share on any PCS 7 station:

Via Windows Computer Management GUI:
* Log into the station with Windows Administrator privileges.
* Press Windows Key + R, type compmgmt.msc, and press Enter.
* In the console tree, expand System Tools > Shared Folders > Shares.
* Locate the share name in the Share Name column (e.g., WinCC_Project_SRV_PM).
* Read the corresponding physical directory under the Folder Path column (e.g., D:\WinCC_Projects\Proj_1\wincproj\OS(1)).
Via Windows PowerShell / Command Line:
* Open PowerShell as Administrator and run:
powershell Get-SmbShare | Select-Object Name, Path, Description | Format-Table -AutoSize
* Or use legacy command:
cmd net share
* Both commands immediately output the exact cross-reference between network share aliases and local disk paths.

Configuring Shared Paths for OS Download and SIMATIC Shell Operation

When configuring target paths in SIMATIC Manager:

Open the PCS 7 Multiproject in SIMATIC Manager on the ES.
Select the OS Server object, right-click, and select Object Properties.
In the Target OS and Master OS tab, verify the UNC target path. It must reference the network share on the OS server (e.g., \\OS_SRV1\WinCC_Project_OS_SRV1).
Ensure the share permissions on the target server include:
* Group SIMATIC HMI: Full Control / Modify.
* Group SIMATIC NET: Read & Execute.
* Group Administrators: Full Control.
If shares were created or permissions disturbed, execute the SIMATIC Security Controller (Start > Siemens Automation > Security Controller > Repeat Settings) to restore all necessary Windows DCOM and SMB folder permissions.

Verification

To confirm proper network share configuration and accessibility:

On the Engineering Station, open Windows Explorer and type the UNC path directly into the address bar (e.g., \\OS_SRV1\WinCC_Project_OS_SRV1).
Verify that the remote folder opens without credentials prompts and displays the .mcp WinCC project file.
In SIMATIC Manager on the ES, right-click the OS Server object and select PLC > Download. Confirm the download initiates without path unreachable or permission denied errors.
Open SIMATIC Shell in Windows Explorer on both stations and verify that all redundant servers and clients appear blue (active) and interconnected.

Limitations and Operational Precautions

Never rename, remove, or recreate shared folders manually via Windows Explorer for an existing PCS 7 project. Manual renaming breaks the Target OS path stored in the ES database and causes OS download failures.
Never share the root drive (e.g., C:\ or D:\) as a replacement for project folder shares; WinCC and Simatic Shell require explicit project folder shares with SIMATIC HMI group permissions.
Changing Windows share names requires updating the Target OS path in SIMATIC Manager and re-executing a complete OS Compile and Download.

Engineer FAQ

Can two different PCS 7 projects share the same network share name on one computer?

No. Windows requires unique share names per host. If two projects on the same machine require network sharing, they must use distinct share names. In typical PCS 7 architectures, each physical computer hosts only one active OS runtime project.

Why do I get 'Path not found' during OS Download even though the share is visible?

This occurs when the ES user account is not a member of the SIMATIC HMI user group on the destination OS server, or if Windows Firewall / Network Profile changed to Public instead of Private/Domain. Run SIMATIC Security Controller to restore firewall and DCOM rules.

Should S7Proj engineering projects on the ES be shared across the network?

Engineering multiprojects (S7Proj) should only be shared if multiple engineering stations collaborate via multi-user engineering. For runtime operation, only the OS runtime target directories on OS Servers need network shares.