Troubleshooting WinCC RT Professional Data Logging Error 1012240

Problem Overview

Operators running WinCC TIA Portal Professional V11 SP2 on Windows 7 Ultimate report that the trend control in runtime displays no historical data when panning back in time. The trend curve is empty, no archive segments are present, and the control behaves as if the logging service never started. Investigation of the WinCC Alarm Logging window reveals two related redundancy errors emitted at the same timestamp:

• 1012240 — REDRT: "<COMPUTERNAME>": RedundancyControl Error Application Health Check in CCDmRtServer_Sync causes state switch.
• 1012241 — REDRT: "<COMPUTERNAME>": RedundancyControl: Switchover to status Fault.

Both messages originate from the CCDmRtServer_Sync component, the WinCC RT Professional change-and-distribution server that synchronizes the in-memory process value buffer to the SQL-based logging database. When the health check inside this service fails, the redundancy control state machine transitions to Fault, the data logging service stops writing new records, and existing buffered segments are flagged as invalid. Trend controls that were never re-opened with a fresh connection then render the archive as empty.

Affected Environment

The same error pattern has been observed on V13 SP1 and V14 environments where the logging database has been detached, the log path is read-only, or the SQL Server service is running under an account without write permission to the archive directory. TIA Portal V11 is end-of-life, so many of the remedies require manual configuration because automated firmware update paths no longer exist.

Error Code Reference

1012240 — RedundancyControl Error Application Health Check

Emitted by the WinCC redundancy control when an internal application health probe returns a non-zero status. The probe polls a defined set of internal services at a configurable interval. A non-zero return from CCDmRtServer_Sync indicates that the change-and-distribution server cannot complete a database transaction within the timeout window.

1012241 — RedundancyControl Switchover to status Fault

Emitted when the redundancy control state machine transitions from Primary or Standby into Fault. In a single-node (non-redundant) runtime, this is a fatal state: the data logging service is suspended and the trend control cannot acquire new archive segments. The state can only be cleared by restarting the WinCC Runtime.

Root Cause Analysis

Five root causes are observed in the field, listed in order of frequency:

1. SQL Server service not running or in recovery state. After a Windows update, the SQL Server (WINCCPLUS) instance may be stuck in Recovery Pending or Suspect. The CCDmRtServer_Sync cannot open a session and the health check fails.
2. Archive path read-only or out of disk space. The default archive path C:\ProgramData\Siemens\Automation\WinCC\<ProjectName>\Archives\ (Windows 7: C:\Documents and Settings\All Users\Application Data\Siemens\...) must be writable by the user account running the SQL Server service and by the WinCC Runtime service.
3. Project migration residue from WinCC V7. When a V7 project is imported into V11 via the TIA migration tool, the database name and connection parameters are sometimes carried over with the old instance name. The V11 runtime then attempts to connect to a non-existent SQL instance and the health check fails within seconds.
4. Trend control configured to a non-existent archive tag. A renamed or deleted process tag referenced in the trend control causes the segment request to return zero rows; the trend view appears empty even though the logging system is healthy.
5. Antivirus or backup software locking the SQL data files (.mdf, .ldf) during a snapshot. This blocks the checkpoint operation and the CCDmRtServer_Sync health probe times out.

Data Logging Architecture (RT Professional)

RT Professional uses a three-layer logging model documented in the WinCC Data Logging (RT Professional) manual. Understanding these layers clarifies where 1012240 originates.

1. Process value buffer (in-memory) — the runtime caches the current value of every archived tag. The buffer is sized by the "Acquisition cycle" and the "Logging cycle" on the tag configuration.
2. CCDmRtServer (change-and-distribution server) — consumes the in-memory buffer, evaluates trigger conditions, and prepares the segment payload. CCDmRtServer_Sync.exe is the synchronization worker that pushes the prepared segment to the database.
3. SQL Server (WinCC logging database) — persists the segment. Default instance name is WINCCPLUS (TIA V11/V13) or WINCC_PRO_RT (TIA V14+). The schema contains the tables dbo.PDL_<TagName> and the configuration table dbo.MCPTArchive.

The application health check probed by the redundancy control includes a ping to CCDmRtServer_Sync. If the sync worker has not flushed a segment within the configured "Timeout for data logging" (default 30 s, parameter Logging.DmRt.SyncTimeout in the WinCC project file), the health check returns non-zero and 1012240 is raised. After three consecutive failures, the state machine moves to Fault and 1012241 is raised.

Diagnostic Procedure

Run the following steps in order. Each step verifies a single layer of the architecture.

Step 1 — Verify SQL Server is running

1. Open Start → Administrative Tools → Services.
2. Locate the service SQL Server (WINCCPLUS) (or SQL Server (WINCC_PRO_RT) on V14+).
3. Status must be Running, Startup type Automatic.
4. If stopped, right-click → Start. If it fails, check Event Viewer → Application for source MSSQL$WINCCPLUS.

Step 2 — Confirm the logging database is online

Open SQL Server Management Studio (SSMS) and connect to localhost\WINCCPLUS using Windows authentication. Run:

Expected output: one row with state_desc = ONLINE. If RECOVERY PENDING or SUSPECT, see the recovery section below.

Step 3 — Validate the archive path

1. In the TIA project tree, open Runtime settings → Services → Data logging.
2. Note the "Storage path" (default: <ProjectPath>\Archive).
3. In Windows Explorer, right-click the folder → Properties → Security.
4. Verify the user account that runs the SQL Server service and the WinCC Runtime service have Modify and Write permissions. On Windows 7, the typical account is SYSTEM or the local user that started the service.
5. Confirm the drive has at least 10 % free space. SQL Server will not start a checkpoint if free space drops below its configured threshold.

Step 4 — Check for migration residue

1. In TIA Portal, open the project and navigate to Project tree → Common data → HMI → Runtime settings → Services → Data logging.
2. Expand "Database connection". Verify the instance name matches the installed SQL Server instance. If the project says WINCCPLUS but the installed instance is WINCC_PRO_RT (V14+ upgrade), the sync worker will fail to connect.
3. Click "Recreate database" to regenerate the schema with the correct instance name. This is non-destructive: existing data is re-attached.

Step 5 — Verify trend control configuration

1. Open the screen containing the trend view.
2. Right-click the WinCC Online Trend Control → Properties → Data Source.
3. Verify the "Archive" dropdown shows the configured data log and the "Tag name" matches an existing process tag.
4. If the dropdown is empty, the archive name was renamed during migration. Rename the archive back, or recreate the trend control with the new archive.

Step 6 — Inspect CCDmRtServer_Sync

Open Task Manager → Details. Confirm CCDmRtServer_Sync.exe is running. If absent, the WinCC Runtime was started before SQL Server was ready, or the service was blocked by antivirus. Add the WinCC install path to the antivirus exclusion list:

Solution

A. Recover the SQL logging database

1. Stop the WinCC Runtime from the WinCC Explorer (or the system tray icon).
2. Open SSMS, connect to localhost\WINCCPLUS.
3. Run: ALTER DATABASE [CC_Project_1] SET EMERGENCY;
4. Run: ALTER DATABASE [CC_Project_1] SET SINGLE_USER;
5. Run: DBCC CHECKDB ('CC_Project_1', REPAIR_ALLOW_DATA_LOSS);
6. Run: ALTER DATABASE [CC_Project_1] SET MULTI_USER;
7. Restart the WinCC Runtime.

B. Reset the redundancy control state

1. Stop the WinCC Runtime.
2. Open Windows Services and restart SIMATIC WinCC RT Professional.
3. Confirm the REDRT alarm messages 1012240/1012241 do not reappear within 60 s. If they do, repeat Steps 1–5 of the diagnostic procedure.

C. Reconnect migrated projects

1. In TIA Portal, open the project.
2. Navigate to Runtime settings → Services → Data logging.
3. Click "Disconnect database" and then "Reconnect database".
4. Compile and download the project to the runtime PC.

D. Adjust the sync timeout (advanced)

If the SQL Server is correctly tuned but the application is large (more than 50,000 tags), the default 30 s timeout may be too short. Edit the file <ProjectName>.hmiscript in the runtime project directory and add:

Recompile the project. This parameter is documented in the WinCC Data Logging (RT Professional) reference.

Verification

1. Start the WinCC Runtime.
2. Open the trend control, navigate to the current time, then pan back 1 hour.
3. The trend curve must render historical data points.
4. Open WinCC Alarm Logging and confirm no REDRT messages with code 1012240 or 1012241 are present in the last 10 minutes.
5. Insert a test value in the PLC and confirm it appears in the trend within one logging cycle.
6. Run the SQL query SELECT COUNT(*) FROM dbo.PDL_<TagName>; and confirm the row count is increasing.

Migration Considerations (WinCC V7 to V11)

Projects migrated from WinCC V7 to WinCC TIA V11 SP2 carry a structural risk: the V7 archive API used ODBC names like CC_V7DB_1, while V11 uses the SQL instance WINCCPLUS. The migration tool updates most references automatically, but two areas require manual review:

1. Tag name length: V7 allowed up to 32 characters; V11 enforces 24 characters in some configurations. Truncated names break the trend control data source.
2. Archive configuration file: The V7 ArchiveManager.xml is converted to V11 native, but custom trigger conditions written in VBScript must be re-validated against the V11 script engine.

After every migration, run the "Project consistency check" in TIA Portal (Project → Compiler → Check consistency) before downloading to the runtime.

Preventive Measures

• Configure a scheduled task that backs up the SQL logging database every 24 h using sqlcmd -S localhost\WINCCPLUS -Q "BACKUP DATABASE [CC_Project_1] TO DISK='D:\Backup\<name>.bak'".
• Monitor the Logging.DmRt.SegmentsDropped performance counter with the WinCC Performance Viewer; a non-zero value indicates segment loss without an alarm.
• Reserve 20 % free space on the archive drive to absorb burst traffic during recipe changes.
• Exclude the WinCC and SQL Server directories from real-time antivirus scanning.
• Update to the latest TIA Portal version currently in general support. V11 reached end-of-life in 2014 and is not covered by Siemens security patches.

Related WinCC Alarm Codes

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