WinCC Tag Logging Archive Backup Configuration Reference

WinCC Tag Logging Archive Backup Configuration Reference

Overview

WinCC Tag Logging provides two parallel storage paths for process value archives: the active runtime store under %ProjectPath%\ArchiveManager\TagLoggingFast and %ProjectPath%\ArchiveManager\TagLoggingSlow, and a user-defined backup destination such as D:\BackupArchive. When backup is activated in the Tag Logging Editor, the WinCC ArchiveManager copies each completed segment from the runtime store to the configured backup directory. Understanding the exact transfer timing, retention rules, and segment-change synchronization is essential for designing a documented, audit-ready process historian that survives drive failures without violating regulatory retention windows.

This reference covers three platforms:

• WinCC V7.5 / V7.5 SP1 (TIA-adjacent configuration in WinCC Explorer)
• WinCC RT Professional in TIA Portal V18 / V19 / V20
• PCS 7 V9.x with Process Historian and Storage Plus

Archive Manager Directory Structure

The WinCC ArchiveManager creates a fixed directory layout under the project root when the runtime database is initialized. The default paths and their purposes are summarized in the table below.

Segment Change and Backup Trigger Timing

A WinCC Tag Logging archive is composed of time-based or size-based segments. A segment change closes the current segment file and opens a new one. The backup operation is triggered by this event.

Per the WinCC documentation, the backup copy normally starts 15 minutes after the first time-related segment change. The 15-minute offset is intentional - it prevents the backup process from contending with the segment-close write that the ArchiveManager is still finalizing. If you require the backup to begin exactly at Runtime start, the start time of the segment change must be defined prior to starting Runtime so that the first segment change coincides with the project activation timestamp.

Backup Configuration in WinCC V7.5 (Tag Logging Editor)

The legacy and current WinCC V7.x configuration is performed inside the WinCC Explorer on the Engineering Station (ES).

1. Open WinCC Explorer on the ES and load the target project.
2. Right-click Tag Logging in the navigation tree and select Open.
3. In the Tag Logging Editor, expand Archives in the navigation area.
4. Select Archive configuration → TagLogging Fast or TagLogging Slow.
5. In the data area, double-click the archive to open the Properties dialog.
6. Switch to the Backup tab.
7. Tick Activate backup.
8. Enter the destination path, for example D:\BackupArchive\TagLoggingFast. The path must exist before runtime starts; the ArchiveManager does not create intermediate directories.
9. Confirm with OK and save the project.

Steps for linking an already-archived backup directory are documented in the Siemens V7.5 support entry "How to Link an Archive Backup - WinCC V7.5" via the shortcut menu Archive configuration → TagLogging Fast/Slow → Link archive.

Backup Configuration in WinCC RT Professional (TIA Portal)

RT Professional uses a different paradigm: each data log owns its own log backup configuration instead of the global ArchiveManager directory.

1. Open the HMI device configuration in TIA Portal.
2. Navigate to Runtime settings → Logs → Data logs.
3. Select the target data log (e.g., ProcessValues_1Hz).
4. Open Properties → Backup.
5. Configure the following parameters:

The TIA Portal V20 cloud documentation "Configuring the log backup (RT Professional)" confirms that "the backup normally starts 15 minutes after the first time-related segment change." This timing is identical to the V7.x behavior, simplifying migration planning.

PCS 7 Backup and Recovery Strategy

PCS 7 extends the WinCC archive model with the Process Historian and Storage Plus for redundancy. The official Siemens whitepaper "PCS 7 - How do you optimize your backup and recovery strategy for the process historian?" (entry ID 109808141) recommends:

• Use a dedicated backup partition or LUN sized for the largest expected retention window (typically 12-36 months for FDA 21 CFR Part 11 installations).
• Separate the Process Historian primary store from the backup volume by physical disk controller (independent I/O path).
• Schedule daily backups during low-load windows (02:00-04:00 local).
• Document and validate the segment-change schedule so the first backup completes within 15 minutes of project start.
• Verify backup integrity with the PH Maintenance tool: phmaintool -verifybackup -path D:\BackupArchive.

For PCS 7 V9.x, the Process Historian mirrors WinCC segments to the configured backup target and additionally replicates to the redundant PH server if configured.

Original Archive vs Backup: Retention Behavior

One of the most common sources of confusion in WinCC archive administration is the asymmetry between the runtime store and the backup destination.

Verifying the Backup Path is Active

1. On the WinCC server, open Windows Explorer and navigate to the configured backup path.
2. Wait at least 15 minutes after the first segment change of the day.
3. Confirm at least one file with extension .MC7 or .DBF (V7.5 legacy) or .tlg (TIA RT Professional) is present.
4. Cross-reference the file timestamp with the expected segment-close timestamp in WinCC Explorer → Tag Logging → Archives → Statistics.
5. If no file appears, check the Windows Application Event Log for sources WinCC ArchiveManager and CCArchiveManager.

Troubleshooting Matrix

Service Account and Security Considerations

The WinCC ArchiveManager service runs under the SIMATIC HMI or the configured CCArchiveMgr user context. The backup destination inherits the same identity. For network paths:

• Use a dedicated service account (do not reuse Administrator).
• Grant Modify on the backup share, not Full Control.
• Set Encrypting File System (EFS) or BitLocker on the backup volume for audit-sensitive installations.
• Disable 8.3 name creation on the backup volume to avoid path-length surprises on long archive names.

For PCI-DSS, 21 CFR Part 11, or IEC 62443 compliance, ensure the backup share supports audit logging at the storage layer (Windows file server audit, NetApp FPolicy, or equivalent).

Capacity Planning Formulas

Estimate the backup storage requirement with the following relationships:

The required backup capacity is:

BackupBytes = N_tags * f_s * B_v * T_ret * K_safety

Worked example: 500 tags at 1 Hz, 4 bytes per compressed value, 365 days retention, 1.3 safety margin:

BackupBytes = 500 * 1 * 4 * (365 * 86400) * 1.3
            = 500 * 4 * 31_536_000 * 1.3
            ~ 82 GB

For higher-frequency logging, substitute the per-tag sampling rate and recompute per archive group (Fast vs Slow).

Verification Checklist

1. Backup destination path exists and is writable by the ArchiveManager service account.
2. First segment change occurs within the first 15 minutes of Runtime start (or scheduled offset).
3. First backup file appears within 15 minutes after the first segment change.
4. Subsequent backup files appear on every segment change without manual intervention.
5. Runtime store (TagLoggingFast/Slow) enforces cyclic retention as configured.
6. Backup destination retains files indefinitely until external purge.
7. Capacity monitoring is in place (e.g., SCADA-side threshold alarms at 70% and 85% disk usage).
8. Restore test has been performed within the last regulatory audit cycle.

FAQ