Configuring External Archiving Providers (Acron) as Windows Services in WinCC Service Mode

In SIMATIC PCS 7 V9.0 SP2, when operating redundant OS Servers in WinCC Service Mode (where WinCC runs in non-interactive Session 0 without an interactive user login), third-party archiving providers like VIDEC Acron V8.5 cannot be launched via the WinCC startup list. Instead, the Acron Provider must be registered as a native Windows Service using the Acron Service Manager. To prevent startup crashes caused by unmounted WinCC archive databases, configure a Windows service dependency on the WinCC project service (CCProjectService) or establish a delayed startup mechanism that verifies the availability of the WinCC SQL Server instance and archive manager before initiating data collection.

Executive Summary

Plant management environments frequently pair SIMATIC PCS 7 with dedicated long-term data archiving and environmental reporting software such as VIDEC Acron (V8.5 or newer). On modern redundant PCS 7 OS Servers operating in WinCC Service Mode, the automation system starts automatically upon Windows boot without requiring an operator desktop logon. However, legacy startup workflows—where Acron data providers were registered in the WinCC Explorer startup application list—fail entirely in Service Mode because Session 0 isolates background tasks. This article details the proper architecture for running third-party data providers as Windows services with WinCC dependencies.

Architecture and Fundamental Mechanics

The Windows operating system enforces Session 0 Isolation to mitigate privilege escalation vulnerabilities. In SIMATIC WinCC:
1. Standard Interactive Mode: WinCC Explorer and all runtime subsystems execute in the interactive user desktop session (Session 1 or higher). Any application listed in Computer Properties -> Startup launches within the user's interactive space.
2. WinCC Service Mode: WinCC Runtime operates as a Windows service in Session 0. WinCC graphic windows, desktop dialogues, and standard startup executables configured for desktop display are strictly suppressed or fail to initialize.

Archiving Provider (Acron V8.5) Integration:
Acron interfaces with WinCC via the WinCC ODK (Open Development Kit) API or directly via WinCC OLE-DB / SQL Server providers to extract compressed historical process values (ArchiveManager\TagExport) and alarm records. If the Acron Provider service initializes before the WinCC Runtime engine has fully mounted its SQL database segments, the provider encounters connection refusals (Error Connecting to WinCC Database) and terminates abnormally.

Analyzing WinCC Background Services:
- CCArchiveConnMon: Starts automatically at Windows boot, but only monitors connection states; it does NOT indicate active runtime archiving.
- CCProjectService / CCDataServer: Initialized when the WinCC project opens and runtime activation begins.
- CCArchiveManagerService: Responsible for active alarm and tag logging, starting only when the runtime engine mounts historical database segments.

Configuring the Acron service to depend on CCProjectService combined with an internal connection retry loop (or 30-second initialization delay) ensures reliable, unattended startup.

Step-by-Step Implementation Procedure

Convert Acron Provider to a Windows Service:
a. Open the VIDEC Acron Service Manager application on the OS Server with administrative privileges.
b. Remove the Acron Provider from the interactive user startup folder and WinCC Explorer startup list.
c. Register the Acron Provider as an automatic Windows Service (AcronProviderService).
Identify Target WinCC Service Name:
a. Open Windows Services management (services.msc).
b. Locate the Siemens WinCC services and inspect their service names: CCProjectService (WinCC Project Service) and CCArchiveManagerService.
c. Confirm their startup type is set to 'Automatic' (as managed by WinCC Service Mode).
Establish Windows Service Dependency:
a. Open an administrative command prompt (cmd.exe).
b. Configure the Acron service to depend on the WinCC project service by executing:
sc config AcronProviderService depend= CCProjectService
(Note: The space after depend= is mandatory in Windows sc syntax).
c. Alternatively, if multiple dependencies are needed:
sc config AcronProviderService depend= CCProjectService/WinCC_SQL_Instance.
Configure Provider Startup Delay and Authentication:
a. In services.msc, right-click AcronProviderService and select 'Properties'.
b. Set 'Startup type' to 'Automatic (Delayed Start)' to provide additional buffer time for SQL archive mounting.
c. Switch to the 'Log On' tab: ensure the service runs under the designated WinCC Service Account (which must be a member of the local SIMATIC HMI group).
d. In the 'Recovery' tab, configure 'First failure' and 'Second failure' to 'Restart the Service' after 1 minute.
Test Redundant Server Reboot:
a. Restart OS Server B to verify automatic unattended startup.
b. Confirm that WinCC Runtime activates in Session 0 and the Acron service establishes database communication without errors.

Verification

In Windows Services (services.msc), verify that both CCProjectService and AcronProviderService show 'Running' status following a system reboot.
Open the Acron diagnostic log (Acron_Provider.log): verify that the provider successfully connects to the local WinCC SQL database without returning authentication or missing database errors.
Open Acron Reporter on an administrative client: confirm that recent process archive values populate continuously from the OS Server.
Check the WinCC Diagnostic directory: confirm that WinCC_Sys_01.log shows clean OLE-DB / ODK connection handshakes.

Limitations and Operational Precautions

Third-party archiving tools querying WinCC SQL Server databases must use read-only queries via the official WinCC OLE-DB Provider or ODK interfaces; directly writing to or modifying internal WinCC SQL tables (CC_<ProjectName>) will cause database corruption, invalidate system warranties, and halt runtime redundancy synchronization.

Engineer FAQ

Why did Acron fail when listed in the WinCC Explorer startup list?

WinCC Service Mode runs in non-interactive Session 0, where applications in the WinCC startup list that expect interactive desktop user sessions cannot launch properly.

What does the service CCArchiveConnMon do?

CCArchiveConnMon is the Archive Connection Monitor service that starts at Windows boot, but it does not represent an active, mounted WinCC runtime project.

Why is 'Automatic (Delayed Start)' recommended for third-party services?

It gives WinCC Runtime and the Microsoft SQL Server instance approximately 2 minutes to mount archive databases before the provider service attempts connection.

What Windows user account should run the Acron Provider service?

The identical Windows account configured in WinCC Service Mode (Project Properties -> Options -> Service), which must belong to the local SIMATIC HMI group.