Resolving WinCC 6.2 Server Name Overwritten by ES Computer Name

Problem Overview

A SIMATIC Manager-integrated WinCC V6.2 project showed the engineering station host name (LAMWRK01) in the WinCC Explorer Computer list, in place of the configured OS server (LAMSRV01). Every subsequent project open returned the prompt "Server not found. Do you want to start server locally?" and selecting Yes rebuilt the local WinCC master database around the current host. The configured clients (LAMCL01, LAMCL02) remained unaffected, and the SIMATIC Manager project tree was still correct. Reinstalling WinCC had no effect because the project's master database file (<ProjectName>.PNL) and runtime configuration (CCConfigure.ini) live in the project folder, not in the installation directory.

Observed Symptoms

• WinCC Explorer → Computer list displays LAMWRK01 instead of LAMSRV01 on the engineering station.
• Manual rename of LAMWRK01 → LAMSRV01 followed by project close/open reverts the server name back to the local host.
• Runtime startup dialog "Server not found - start server locally?" appears on every project open.
• SIMATIC Manager project hierarchy is intact, with Server Name (LAMSRV01), WinCC Application, and Project Name WinCC nodes in place.
• Client entries LAMCL01 and LAMCL02 are still listed.
• No backup OS exists - the project was never re-downloaded from the engineering station.

Root Cause Analysis

The behavior is reproducible and corresponds to the documented Siemens Support entry 15252277. When WinCC Explorer is opened on a station that is not the configured server, WinCC attempts to bind to the Computer list entry for the configured server. If the named server cannot be resolved on the network, the runtime issues the prompt "Server not found - Do you want to start the server locally?". Selecting Yes rewrites the local project copy so that the local computer name takes over the role of the configured server name.

The information that ties a SIMATIC Manager WinCC project to its OS station lives in three places:

1. SIMATIC Manager OS reference in the S7/PCS 7 project hierarchy, which names the target computer for the OS station and drives what computer name is written into the master database at download time.
2. WinCC master database <ProjectName>.PNL, which holds the Computer list shown in WinCC Explorer.
3. Runtime boot file CCConfigure.ini, which contains the [Server] section read at runtime start.

Once a server-name rewriting pass has been executed on the engineering station, the next launch of WinCC on the same station again asks for the server, again reverts to the local name, and the OS reference in SIMATIC Manager no longer matches the WinCC Explorer project state. Renaming LAMWRK01 → LAMSRV01 in WinCC Explorer only changes the display entry until the next save - it does not change the OS reference that resolves host names at runtime startup. Reinstalling WinCC wipes the installation directory but leaves the project directory and its master database untouched.

Pre-Diagnostic Checklist

Run the following commands on LAMWRK01 before touching any project files. If server-name resolution is broken at the operating-system level, fixing it removes the prompt directly.

If any DNS/WINS/hosts resolution check fails, repair the OS-side naming first. In many support cases the prompt disappears without any project surgery.

Solution Workflow

Four procedures are presented, ranked from recommended (procedure 1) to last-resort (procedure 3). Procedure 1 is the supported path in a production PCS 7 / WinCC V6.2 environment.

Procedure 1 - Re-download the project from ES to OS with corrected OS reference

The OS reference in SIMATIC Manager on the engineering station tells Download which target computer name to stamp into the project master database. A complete download from the ES to the OS re-creates the binding with the correct server name.

Prerequisites

• SIMATIC WinCC V6.2 with a valid runtime license on the OS station LAMSRV01.
• OS station reachable from the ES by name and IP (pass the pre-diagnostic checklist).
• SIMATIC Manager open on LAMWRK01 with the project that contains Server Name (LAMSRV01).
• S7-400 / S7-300 station CPU online and accessible via the configured Ethernet route.
• S7DOS Helper Service running on both stations.

Step-by-step

1. In SIMATIC Manager, right-click Server Name (LAMSRV01) and choose Object Properties. Open the WinCC tab.
2. Confirm the Computer Name field reads exactly LAMSRV01. If the project state shows LAMWRK01, correct it to LAMSRV01 and apply. This is the OS reference that Download will use.
3. Open the OS project locally: right-click WinCC Application → Project Name WinCC → Open in WinCC Explorer. Close WinCC Explorer again without saving to flush any cached local-host binding.
4. Back in SIMATIC Manager, right-click Server Name (LAMSRV01). Choose Target system → OS → Complete download.
5. The dialog prompts to choose the OS target. Accept the configured computer name LAMSRV01 and confirm with OK.
6. WinCC remote service accepts the download. On the OS, CCProjectMgr.exe receives the master database, graphics, and server-name binding.
7. Wait for the dialog Download complete before continuing. Exit the dialog. Start WinCC Runtime on the OS (WinCC Explorer → Activate Runtime).
8. Re-open the project in WinCC Explorer on the ES. The Computer list should now show LAMSRV01 as the server entry with the green status indicators and the runtime icons blue.

What if "Complete Download" is rejected?

• If Computer Name and Server Computer do not match, the dialog blocks with the error "OS reference does not match". Set both to LAMSRV01.
• If the OS is unreachable, the dialog aborts with a TCP timeout. Fix network reachability first, then retry.
• If the ES shows a license error, confirm the runtime license on the OS with Automation License Manager → View Available Licenses.

Procedure 2 - Re-set the OS reference without re-download

Use this when the engineering station cannot reach the OS for a download but the SIMATIC Manager tree still appears correct. The mismatch is between the SIMATIC Manager OS reference and the local WinCC master database on the engineering station.

1. In SIMATIC Manager select Server Name (LAMSRV01); press Alt+Enter to open Properties.
2. Tab WinCC: set Server name to LAMSRV01 and Server computer to LAMSRV01. Apply and confirm the prompt that the project will be recompiled.
3. Right-click the Server Name node and choose Open in WinCC Explorer. Close WinCC Explorer without saving.
4. Stop the SIMATIC WinCC CCProjectMgr service on the ES to flush any cached local-host binding.
5. Re-start the service and verify the Computer list with WinCC Explorer: the server entry should read LAMSRV01.
6. Schedule a Complete Download as soon as OS network access is available so the master database on the OS is realigned to the corrected local-side binding.

Procedure 3 - Manually correct the WinCC master database (last resort)

Use only when neither ES nor OS can talk to the other, no current archive exists, and the project must be made usable from the engineering station. This is invasive; create a full backup of the project folder before starting.

Default WinCC V6 project file locations

Procedure

1. Stop WinCC Explorer on the ES and stop the SIMATIC WinCC CCProjectMgr service.
2. Copy the entire project folder to <Project>_backup_YYYYMMDD.
3. Open <ProjectName>.PNL in a hex editor (HxD, WinHex). Search ASCII for LAMWRK01; replace only the instance that corresponds to the server-role entry with LAMSRV01. Do not touch other strings; the file has internal offsets that depend on the byte-exact layout.
4. Edit CCConfigure.ini with Notepad. Locate the [Server] section and confirm ServerName=LAMSRV01. Save the file as UTF-16 LE without BOM if Notepad prompts.
5. If a redundancy configuration is present, open Redundancy.TXT and validate that the partner name still matches the configured standby server.
6. Re-start CCProjectMgr. Open the project in WinCC Explorer and verify the Computer list.
7. If WinCC Explorer reports Database corrupted, restore from the backup and escalate to procedure 4.

Procedure 4 - Restore the project from a known-good archive

If a project archive (*.zip, *.tar, *.bak) was produced with SIMATIC Manager → Archive prior to the incident, de-archive it into an empty directory on the ES. The de-archived project starts with the original server-name binding. Re-run the OS reference settings as in procedure 2 before any download.

Verification Steps

1. Open WinCC Explorer → Computer on the ES. Confirm LAMSRV01 is listed as the server entry with the green icon, not LAMWRK01.
2. Start runtime on the OS. Watch the bottom status bar of WinCC Explorer - the server entry should turn from grey to green once the runtime is fully started on the OS.
3. Sign in on LAMCL01 and LAMCL02 with a configured user; both clients should connect to the server without errors.
4. Trigger a tag update from the AS. The value should propagate through the server to both clients within one cycle (typically 250 ms - 1 s for WinCC).
5. Inspect <Project>\<ProjectName>_<date>.LOG in the project folder for any Server disconnect / reconnect traces around startup. Absence of these is the cleanest signal that the binding is correct.
6. Close and re-open the project three times consecutively. The server name must remain LAMSRV01 on every open, with no start server locally prompt.
7. Reboot the engineering station to confirm that the binding persists across cold boots, not just warm restarts.

Server / Client / ES Role Reference

The relationships between the engineering station, the WinCC server, and the client stations in a V6.2 SIMATIC-Managed layout are summarized below.

Best Practices to Avoid Re-Occurrence

• Treat the engineering station as a single-purpose SIMATIC development host. Open unrelated WinCC projects only on a dedicated secondary machine so their master databases never cross paths with the managed one.
• Always keep a current OS package image. With an OS source available, Complete Download re-stamps the server-name binding in a single, traceable operation.
• Disable Auto-Download Server experiments unless the OS is wired up. The prompt "Do you want to start the server locally?" should never be accepted on an ES that is not licensed for runtime - the prompt is itself a cue that something is misconfigured.
• Use a backup virtual machine that mirrors the OS hardware profile. A virtual OS lets you verify that Complete Download finishes cleanly before putting the production OS at risk.
• Document every download in a logbook with date, ES operator, OS station name, download type (Complete / Changes) for traceability and root cause analysis.
• Maintain a current archive of the project, refreshed after every successful download or significant change, so procedure 4 is always available.

Integrating OPC Connectivity after the Server Name is Restored

Once the server-name binding is correct and runtime activates, integration with external data sources such as TOP Server via OPC DA completes the data path. The TOP Server / WinCC V6 integration provides a worked example of building an OPC Channel in Tag Management, browsing the server's namespace in OPC Item Browser, and validating each tag mapping from the diagnostics view before runtime activation.

• Reference: Software Toolbox - Using TOP Server with WinCC V6

Troubleshooting Matrix

Reference Procedure - First Download of a SIMATIC-Managed WinCC Project

The procedure that originally establishes the OS reference is the same procedure that fixes the issue. For new project commissioning on a fresh OS, execute the following in sequence:

1. On the OS, install the matching WinCC V6.2 build and load the runtime license.
2. Configure PG/PC Interface on both ES and OS so the S7ONLINE access point targets the same Ethernet adapter.
3. Set the OS Reference on the ES: SIMATIC Manager → Server Name → Object Properties → WinCC tab → Computer name = LAMSRV01.
4. Right-click WinCC Application → Project Name WinCC and choose Open in WinCC Explorer on the ES. Save and close.
5. Right-click Server Name (LAMSRV01) and choose Target system → OS → Complete download. Select the configured computer LAMSRV01.
6. The download progresses through Compile OS, Transfer master database, Transfer graphics, and Activate Runtime.
7. Confirm the green icon on the ES-side Computer list. Runtime is then live on the OS.

FAQ