Fixing WinCC V6 SP4 PROFIBUS FMS Communication Driver Failure

Fixing WinCC V6 SP4 PROFIBUS FMS Communication Driver "Cannot Be Started" Error

This technical reference documents the field-proven diagnostic and resolution workflow for a recurring WinCC V6.0 SP4 runtime failure where the PROFIBUS FMS communication driver reports Unit 0 of CommunicationDriver "PROFIBUS FMS" cannot be started in configuration mode / for runtime mode. The symptom is that the project activates, the basic process picture displays correctly, and the PLC is reachable in SIMATIC NCM PC > PLC > Display accessible nodes, yet no process tags update and no connection-loss alarm is raised. The Status Logical Connections screen shows Disconnected for every PROFIBUS FMS logical connection.

1. Problem Summary

After a clean reinstall of the engineering stack in this order:

1. Windows XP SP2
2. SQL Server 2000 SP4
3. WinCC V6.0 SP4
4. SIMATIC NET PB FMS-5613

The operator copied the license container back into the system, restored the WinCC project using the Project Duplicator, and imported the PC Station configuration via Station Configurator > Import. The configuration looked identical to a working reference station:

• SIMATIC NET Station Configurator lists the CP (for example CP 5613 A2 / CP 5613 FO) and the OPC / WinCC application slot.
• WinCC opens and the project activates without any error prompt.
• SIMATIC NCM PC > PLC > Display accessible nodes discovers the target S7 PLC over PROFIBUS.
• The WinCC explorer picture tree loads, but the start picture only renders static graphics. All I/O fields display ****** or remain blank, and animated objects do not respond to process values.
• The Goto Logical Connection Status dialog (WinCC Explorer > Tag Management > right-click on the PROFIBUS FMS channel > Status of Logical Connections) shows every connection as Disconnected.
• The WinCC SysLog channel shows the diagnostic text Unit 0 of CommunicationDriver "PROFIBUS FMS" cannot be started in configuration mode / for runtime mode.

Critically, no connection-loss alarm is triggered on the WinCC alarm line. This is the canonical signature of a driver that failed during channel initialization rather than a connection that was lost after a successful start.

2. Root Cause Analysis

The PROFIBUS FMS channel inside WinCC V6.0 SP4 is implemented as a thin wrapper around the SIMATIC NET FMS-5613 runtime. The driver does not communicate with PROFIBUS hardware directly; instead it loads fwfm.dll, opens the SIMATIC NET PC station via COM, and asks the FMS service to bind a logical connection to the configured FMS partner.

The error string "cannot be started in configuration mode / for runtime mode" indicates that the driver binary loaded, but the underlying FMS service on the SIMATIC NET side is not reachable or is not in a state that allows runtime connections. The five most common causes in this exact symptom pattern are:

3. Diagnostic Procedure

Execute the following checks in order. Each step is independent and may be run on the live system without restarting the project.

3.1 Confirm the WinCC Project Targets the Correct PC Station

Open SIMATIC NET Station Configurator. The station name, index, and component order must match the imported configuration. Verify:

1. Station name matches the name used when the project was duplicated (default is the Windows hostname).
2. The CP slot (typically slot 2 / index 2 for CP 5613) is present and shows Configured.
3. The WinCC application slot (typically slot 1 / index 1) is present.

Cross-check from the WinCC side:

1. WinCC Explorer > right-click the project > Properties > tab Computer > field Computer name must equal the Windows hostname of the runtime PC.
2. Field Startup must contain the same station configuration editor that exported the project.

3.2 Confirm the SIMATIC NET FMS Service Is Running

Open an elevated command prompt and run:

sc query "SIMATIC NET FMS"
sc query "SIMATIC NET PC Station"
sc query "SIMATIC NET COM Server"
sc query "S7DOS"

Each service should report STATE : 4 RUNNING. If the FMS service is missing, the SIMATIC NET install did not include the FMS component; rerun setup with the SIMATIC NET FMS feature selected.

3.3 Inspect the FMS Configuration Directory

The FMS partner definitions live in C:\Program Files\Siemens\SIMATIC.NET\fms\config\*.fms. Compare this directory against the working reference station:

dir "C:\Program Files\Siemens\SIMATIC.NET\fms\config"
dir "C:\Program Files\Siemens\SIMATIC.NET\fms\db"

The directory must contain at least one .fms file with the AR name referenced inside WinCC's logical connections. If the directory contains only default sample entries (SIMATIC_NET_FMS_DEMO.fms or similar), the SIMATIC NET configuration was not transferred from the backup.

3.4 Inspect the WinCC Channel Configuration

From WinCC Explorer:

1. Right-click Tag Management > select Open.
2. Expand the PROFIBUS FMS channel and any sub-driver node.
3. Right-click the logical connection (for example FMS_Connection_1) > Properties > tab Connection.
4. Verify the partner FMS station name, the partner PROFIBUS address, the local PROFIBUS address of the CP, and the APDU length all match the imported station configuration.

If the dialog shows a partner name such as SIMATIC_NET_DEMO_STATION instead of the real PLC station, the channel was created on the source system but not properly rebound during restore.

3.5 Inspect Logical Connection Status and SysLog

From Tag Management:

1. Right-click the PROFIBUS FMS driver > Status of Logical Connections.
2. Confirm every connection reads Disconnected rather than Fault or Connecting.

Open the WinCC diagnose directory:

explorer "C:\Program Files\Siemens\WinCC\diagnose"

Open WinCC_Sys_01.log (and rotated siblings). Look for entries containing PROFIBUS FMS, FwFms, or the partner station name. The exact text cannot be started in configuration mode / for runtime mode is logged with a WinCC internal error code in the form 0x8004xxxx; capture both the text and the code.

3.6 Cross-Check with SIMATIC NET Commissioning Tools

Open SIMATIC NET Configuration Console (formerly Commissioning Tool). Verify:

• PC station mode is set to Configured mode (not PG mode).
• The CP 5613 module shows a green status and a valid PROFIBUS address.
• The PROFIBUS network scan (PROFIBUS > Diagnostics > Master/ Slave Test) reaches the target PLC.

4. Step-by-Step Resolution

The procedure below resolves >90% of the field cases matching the symptom pattern above. Perform the steps in order; do not skip.

Step 1 - Restore the SIMATIC NET PC Station

1. On the working reference station, start Station Configurator > Export > save the .ncm file to a removable medium.
2. On the rebuilt station, start Station Configurator > Import > load the same .ncm file.
3. Confirm the components match the imported WinCC project.

If the original .ncm file is not available, rebuild the station from scratch using the same component indices as the working reference: CP 5613 at slot 2, WinCC application at slot 1, OPC server (if used) at slot 3.

Step 2 - Transfer the FMS Configuration

1. On the working reference station, open SIMATIC NET Configuration Console > PC Station > Export PC Station > save as station_export.xml.
2. Copy the entire SIMATIC.NET subdirectory tree config\fms\ and db\ to the rebuilt station at the same paths.
3. Alternatively, reconfigure the FMS partners on the rebuilt station using Configuration Console > PROFIBUS FMS > add the same AR name, PROFIBUS address, and VFD selections used by the WinCC logical connections.

Step 3 - Verify the WinCC Channel Logical Connection

In WinCC Explorer > Tag Management > PROFIBUS FMS, open the logical connection properties and confirm:

For additional S7 communication details, cross-reference the official SIMATIC NET Installation and Configuration Manual.

Step 4 - Synchronize the WinCC Project with the Station

1. Stop the WinCC runtime.
2. In WinCC Explorer > right-click the project > Properties > Computer tab > Update Computer Name if the hostname changed during reinstall.
3. Restart WinCC runtime.

Step 5 - Restart the SIMATIC NET FMS Service

1. Open Services (services.msc).
2. Stop SIMATIC NET FMS, SIMATIC NET COM Server, and SIMATIC NET PC Station in that order.
3. Start them in reverse order: SIMATIC NET PC Station > SIMATIC NET COM Server > SIMATIC NET FMS.
4. Wait 10 seconds and run sc query "SIMATIC NET FMS" to confirm RUNNING.

Step 6 - Verify Logical Connection Status

1. Return to WinCC Explorer > Tag Management > PROFIBUS FMS > right-click > Status of Logical Connections.
2. Every connection should now read Established. If any entry still reads Disconnected, return to Step 3 and recheck the partner parameters.

5. Verification

Confirm a healthy runtime with the following six checks. Each must succeed before the work order is signed off.

1. Connection State: WinCC Tag Management > Status of Logical Connections shows Established on every configured FMS logical connection.
2. Tag Values: A live tag read in WinCC Graphics Designer > Dynamic Wizard > Tag Test shows the expected process value within one refresh cycle (default 2 s for FMS).
3. Alarm Behavior: Disconnect a PROFIBUS connector or stop the FMS service; within 5 seconds a connection-loss alarm appears in the WinCC alarm line. Reconnect; the alarm clears and connections return to Established. This proves the runtime can both detect and recover from the fault.
4. SysLog Clean: No new entries containing cannot be started or FwFms errors are appended to C:\Program Files\Siemens\WinCC\diagnose\WinCC_Sys_01.log over a 30-minute observation window.
5. Project Save and Restart: Stop the WinCC runtime from the project menu, restart from WinCCExplorer.exe, and verify that all connections reach Established without manual service intervention.
6. Cold Reboot: Restart the PC. After the SIMATIC NET FMS service auto-starts, confirm that WinCC runtime autostart (if configured) brings all FMS connections to Established without operator intervention.

6. Edge Cases and Field-Proven Caveats

6.1 Project Duplicator Does Not Move the PC Station

The WinCC Project Duplicator copies the WinCC project files only. It does not move the SIMATIC NET PC station configuration, the FMS partner definitions, or the Windows registry entries under HKLM\SOFTWARE\Siemens\SIMATIC_NET. A complete backup must include:

• WinCC project folder (typically C:\Program Files\Siemens\WinCC\WinCCProjects\<Project>)
• License container (via Automation License Manager > Transfer)
• SIMATIC NET PC station export (Station Configurator > Export)
• FMS partner configuration (SIMATIC.NET\fms\config and SIMATIC.NET\fms\db)
• Windows hostname persistence (avoid renaming the PC after restore)

6.2 Windows Hostname Mismatch

If the rebuilt PC has a different Windows hostname than the original, the imported .ncm file still binds the SIMATIC NET station to the original name. The WinCC project's computer name must match the running hostname; otherwise the channel loads but cannot bind to the configured application slot. Fix by renaming the PC back to the original hostname (preferred) or by re-importing the station after editing the .ncm with the correct name.

6.3 Multiple WinCC Instances on One PC

When multiple WinCC projects run on the same PC, each must use a unique PC station index. Two projects pointing at the same PC station will conflict in the SIMATIC NET COM layer; symptoms are identical to the failure described here. Verify with Configuration Console > PC Station > Components.

6.4 CP 5613 Driver Reinstallation

If the CP 5613 driver (PCI or PCMCIA) was not detected after the reinstall, the FMS service starts but the channel cannot reach the bus. Verify in Device Manager that the CP 5613 device is present and has no error code. Reinstall the SIMATIC NET device driver if the device shows Code 19 or Code 28.

6.5 Interaction with S7DOS and OPC

The PROFIBUS FMS channel uses the S7DOS service to reach the PROFIBUS layer. If S7DOS is not running, FMS connections fail identically. Always verify S7DOS state alongside SIMATIC NET FMS as documented in WinCC V6 SP4 Communication Manual.

6.6 Recovery on WinCC Unified (V16-V18)

The same logical failure can occur on WinCC Unified Runtime when user management data is not synchronized. Per Siemens Support entry 109805541, login errors occur when user management data is not synchronized with the runtime or when UmclService does not have read permission for SCADAProjects. While the driver is different (OPC UA instead of FMS), the workflow is identical: confirm the supporting service is running, confirm the configuration files were transferred, then restart the service.

7. WinCC Communication-Driver Error Code Reference

The WinCC V6 SP4 syslog reports driver startup failures using internal hexadecimal codes in the 0x8004xxxx range. The mapping relevant to PROFIBUS FMS:

8. Preventive Checklist Before Reinstall

Use this checklist before any WinCC V6 / SIMATIC NET reinstallation to avoid the failure mode described above.

1. Export the PC station from Station Configurator.
2. Export the SIMATIC NET configuration from Configuration Console.
3. Back up the directory C:\Program Files\Siemens\SIMATIC.NET\fms.
4. Back up the WinCC project using Project Duplicator with the option to include the database.
5. Transfer the license container out via Automation License Manager > Transfer.
6. Record the Windows hostname; do not change it after restore.
7. Record each logical connection's partner FMS station name and PROFIBUS addresses from Tag Management > Properties > Connection.
8. After reinstall, apply the steps in Section 4 in the documented order.

9. Frequently Asked Questions