Troubleshooting Process Historian Not Receiving Process Tags from WinCC Tag Logging

When SIMATIC Process Historian (PH) fails to receive historical tag logging data from WinCC OS Servers, the failure is primarily caused by stalled Microsoft Message Queuing (MSMQ) outgoing queues, uninstalled or corrupted 'Process Historian Ready' components on the OS Servers, or mismatched SQL Server communication states. In PCS 7, OS Servers stream tag logging archives asynchronously to PH via MSMQ. If the MSMQ storage quota is exceeded, if the OS Server is not registered in the Process Historian Management Console (PHMC), or if DNS name resolution fails across the Terminal Bus, tag streaming halts. To resolve this, verify MSMQ queue delivery, ensure the PH Ready service is active, register the OS Server in PHMC, and purge stalled message buffers.

Architecture of Tag Logging Data Streaming to Process Historian

In SIMATIC PCS 7 (V8.0, V8.1, V8.2, and V9.0), SIMATIC Process Historian (6ES7652-7AX58-0YA0) serves as the central, long-term plant archive for all OS Servers, Batch Servers, and Route Control systems. The streaming of historical process tags (Tag Logging Fast and Tag Logging Slow) differs fundamentally from short-term local circular logs.

The data ingestion pipeline consists of:
1. WinCC Tag Logging Engine (CCAlgDataMgr.exe / CCTlgServer.exe): Writes real-time tag samples to local short-term SQL Server segments on the OS Server.
2. Process Historian Ready Component (CCProcessHistorian.exe): Installed on every OS Server (6ES7652-7BX58-0YB0), this background agent monitors Tag Logging archives and serializes tag packages for transmission.
3. Microsoft Message Queuing (MSMQ): WinCC pushes tag packets into dedicated transactional MSMQ private queues (private$\PH_Data_Queue). MSMQ handles asynchronous, store-and-forward transmission over the Terminal Bus.
4. PH Ingestion Service (ProcessHistorianDataService.exe): Consumes incoming MSMQ packets on the central PH server and executes bulk SQL INSERT operations into the Microsoft SQL Server enterprise database.

Root Causes of Tag Logging Data Transmission Stalls

When process tags fail to appear in Process Historian or Information Server reports, investigation reveals four typical failure modes:

MSMQ Outgoing Queue Stalled or Saturated: By default, Windows MSMQ allocates a maximum storage limit (typically 1 GB or 4 GB). If the network connection between OS and PH is interrupted, or if PH cannot process packets fast enough, the queue fills to 100%. Once saturated, WinCC drops new tag packages, permanently halting transmission.
OS Server Not Registered or Disconnected in PHMC: The Process Historian Management Console (PHMC) maintains a whitelist of authorized data sources. If the OS Server was renamed, re-imaged, or its computer certificate expired, PH marks the server status as 'Disconnected' or 'Unauthorized'.
Terminal Bus Name Resolution Failures: MSMQ uses direct NetBIOS and DNS computer names (FormatName:DIRECT=OS:<PH_Server>\private$...). If DNS fails or the hosts file lacks accurate IP-to-hostname mappings, MSMQ cannot establish socket connections.
WinCC Historian Status Flag Inactive: In WinCC Explorer, under Computer Properties -> Process Historian tab, the status indicator must read 'Active'. If unlinked, the OS Server assumes local-only archiving.

Comparison of Data Streaming Diagnostics: OS Server vs Process Historian

The following table compares diagnostic indicators and log locations between OS Server and Process Historian:

Diagnostic CheckpointLocation / ToolNormal Operational StateError / Stall IndicationWinCC PH Ready StatusOS Server: WinCC Explorer -> Computer Properties'Process Historian: Active''Inactive', 'Disconnected', or Greyed OutMSMQ Outgoing QueuesOS Server: compmgmt.msc -> Services and Applications -> Message QueuingQueue empty or oscillating < 10 messagesQueue state 'Paused' or thousands of unacknowledged packetsPH Data Source StatePH Server: Process Historian Management Console (PHMC)OS Server listed with Green checkmarkRed cross, 'Offline', or 'License Missing'WinCC System DiagnosticsOS Server: WinCC\Diagnose\WinCC_Sys_01.logZero MSMQ errorsMSMQ error 0xc00e0027: Queue storage quota exceededPH Database Commit RatePH Server: Windows Performance Monitor (perfmon)Continuous SQL transactions/sec0 transactions/sec; SQL Server disk idleTerminal Bus HeartbeatOS Server to PH Server: ping -a <PH_Hostname>Reply < 1ms with verified hostnameRequest timed out or unresolved host name

Step-by-Step Procedure to Diagnose and Restore Tag Streaming

Follow this procedure to recover stalled tag logging data streaming into Process Historian:

Verify Terminal Bus Network and Host Resolution:
- From the OS Server, open Command Prompt and execute ping -a <PH_ComputerName>.
- Ensure bidirectional ping succeeds using hostnames, not just IP addresses. If resolution fails, update the Windows hosts file (C:\Windows\System32\drivers\etc\hosts).
Check MSMQ Outgoing Queue Status on OS Server:
- Open Computer Management (compmgmt.msc).
- Expand Services and Applications -> Message Queuing -> Outgoing Queues.
- Locate the queue pointing to the Process Historian server.
- If state is 'Paused', right-click and select Resume.
- If the queue contains thousands of orphaned packets and reports quota exceeded, increase the MSMQ quota under Message Queuing Properties -> General tab (e.g. increase to 8,000,000 KB).
Verify OS Server Registration in PHMC:
- Log onto the Process Historian server with administrative privileges.
- Open the Process Historian Management Console.
- Under Data Sources, verify that the OS Server appears in the list.
- If the status is 'Unknown' or 'Offline', right-click the server and select Authorize / Activate Data Source.
Restart PH Ready Services on OS Server:
- In Windows Services (services.msc) on the OS Server, locate SIMATIC Process Historian Ready Component.
- Restart the service.
- In WinCC Explorer, verify that the Process Historian status icon returns to green/active.
Monitor Tag Streaming Recovery:
- Watch the MSMQ outgoing queue in Computer Management. The message count should steadily decrement as cached tag packets are transmitted to PH.

Verification

Confirm data streaming restoration through the following verifiable steps:
1. In the Process Historian Management Console, navigate to Diagnostics -> Performance Counters. Verify that 'Tags processed/second' shows active non-zero values.
2. Open SIMATIC Information Server in a web browser. Generate a trend report for an active analog tag (e.g., reactor temperature) over the past 2 hours. Confirm that continuous trend points populate without time gaps.
3. On the OS Server, verify that the MSMQ outgoing queue remains below 50 messages during normal runtime cycles.
4. Check the PH diagnostic log (C:\ProgramData\Siemens\ProcessHistorian\Trace\) to confirm clean database bulk copy acknowledgments.

Limitations and Operational Precautions

Never Manually Purge Active MSMQ Queues: Purging the outgoing MSMQ queue on an OS Server permanently deletes historical tag data that has not yet reached the Process Historian. Only purge queues as a last resort during initial commissioning.
SQL Server Database Growth: Ensure the Process Historian data and log drives have adequate disk space. If the disk hosting the SQL Server database runs below 10% free space, Process Historian halts all incoming data ingestion to protect database consistency.
License Constraints: Process Historian requires valid Basic Package and Archive Tag count licenses in Automation License Manager. If license counts are exceeded, tag archiving stops after a grace period.

Engineer FAQ

Why are alarms archiving to Process Historian, but tag logging is not?

Alarms and process tags use separate transmission channels. Alarms use smaller payload packets that may succeed even when tag logging queues are saturated or when Tag Logging Fast/Slow archive segments fail to trigger export events.

What happens to tag data if the Process Historian server goes offline for maintenance?

The Process Historian Ready component buffers tag packets locally inside the OS Server's local SQL database segments and MSMQ queues. When the PH server comes back online, the OS Server automatically transfers the buffered data in a store-and-forward sweep.

Where is the Process Historian Ready software installed?

Process Historian Ready must be installed on every WinCC OS Single Station, OS Server pair, and SIMATIC BATCH Server. It is included on the PCS 7 installation media under additional software.