Architecting SIMATIC Process Historian and Information Server in PCS 7

In SIMATIC PCS 7, long-term central data archiving and web reporting are decoupled from runtime OS Servers by deploying SIMATIC Process Historian (PH) and SIMATIC Information Server (IS). Process Historian utilizes Microsoft SQL Server Enterprise with circular segment storage to archive terabytes of real-time process values, messages, and batch records from multiple OS Servers. Information Server provides thin-client, web-based reporting (reporting across shifts, batches, and alarms). Successful deployment requires dedicated server hardware, high-speed RAID disk arrays, and proper licensing.

Process Historian vs. Central Archive Server (CAS) Evolution

In legacy SIMATIC PCS 7 versions (V6.x and V7.x), long-term process archiving relied on the Central Archive Server (CAS) (StoragePlus / WinCC CAS). CAS suffered from significant architectural bottlenecks: storage capacity was limited, database recovery after communication interruptions was fragile, and generating cross-plant web reports required complex custom SQL queries.

Starting with PCS 7 V8.0, Siemens introduced the modernized archiving suite:
* SIMATIC Process Historian (PH): A high-performance, real-time database server based on Microsoft SQL Server. It automatically acquires and archives process variables, alarms, and SIMATIC BATCH data from multiple OS Servers in real time.
* SIMATIC Information Server (IS): A web-based reporting platform built on Microsoft SQL Server Reporting Services (SSRS). It allows operators, engineers, and plant managers to create, schedule, and view customized reports (Excel, Word, PDF) from any standard web browser without installing specialized client software.

Process Historian Database Architecture and Segmentation

Process Historian is engineered for high data throughput and multi-year data retention:
* Data Sources: Redundant OS Server pairs, Single Stations, and SIMATIC BATCH Servers connect over the Terminal Bus.
* Real-Time Replication: WinCC OS Servers maintain local short-term circular archives (typically 1 to 2 weeks of data). Simultaneously, the background service CCProcessHistorian.exe streams data records to the PH.
* Store and Forward: If the PH server or network is temporarily offline, OS servers buffer data locally. When PH connectivity restores, all buffered data is automatically backfilled into the historian without data gaps.
* Storage Segmentation: PH partitions data into Database Segments (Active, Closed, and Detached). Older closed segments can be automatically backed up to network storage or offline optical/tape media, ensuring the primary SQL database remains lean and performant.

Information Server Reporting Framework and Web Delivery

Information Server runs as a web portal hosted on Microsoft Internet Information Services (IIS):
* Template-Driven Reporting: Includes pre-configured industrial templates for shift logs, alarm frequency Pareto charts, PID loop tuning trends, and batch production summaries.
* Automated Distribution: Reports can be scheduled to run automatically (e.g. end-of-shift at 06:00, 14:00, 22:00) and automatically emailed to supervisors as PDF or Excel attachments.
* Direct Office Add-Ins: Engineers can embed live Process Historian historical queries directly into Microsoft Excel worksheets, creating self-updating production dashboards.

Historian Architecture and Sizing Parameter Matrix

The following matrix outlines hardware sizing and licensing guidelines for Process Historian:

Architectural MetricSmall Plant (< 5,000 Tags)Medium Plant (5,000–50,000 Tags)Large Enterprise (> 50,000 Tags)Server HardwareSIMATIC IPC647D / IPC847DDedicated Server Class HardwareRedundant PH Server PairCPU / Memory4 Cores, 16 GB RAM8 Cores, 32 GB RAM16+ Cores, 64 GB+ RAMStorage ArchitectureRAID 1 (OS) + RAID 5 (Data)RAID 1 (OS) + RAID 10 (Fast Data)Fiber SAN / High-Speed Enterprise RAIDNetwork Interface2x Gigabit RJ454x Gigabit RJ45 (Teaming)Dual 10 Gbps Fiber NetworkPH Software LicensePH Basic Package (6ES7652-0...)PH Basic + Tag Expansion PacksRedundant PH + Enterprise LicensingIS Software LicenseIS Basic (1–3 Clients)IS Multi-Client PackageIS Enterprise Client License

Step-by-Step Commissioning and Integration Workflow

Follow this procedure to deploy Process Historian and Information Server:
1. Prepare Hardware and Storage Volumes:
- Format independent disk arrays: Drive C:\ for OS, Drive D:\ for SQL Database Data files, Drive E:\ for SQL Transaction Logs, Drive F:\ for Historical Archives.
- Install Windows Server (e.g. Windows Server 2012 R2 Standard 64-bit).
2. Install Process Historian and SQL Server:
- Run the Process Historian installation media.
- Allow the installer to deploy Microsoft SQL Server Enterprise and configure database file paths across your segregated RAID arrays.
- Run the Process Historian Ready configuration wizard to initialize database catalogs.
3. Configure Information Server:
- Install SIMATIC Information Server on the same machine (or on an independent reporting server).
- Configure IIS and bind Microsoft SQL Server Reporting Services.
4. Integrate with PCS 7 OS Servers:
- On the Engineering Station in SIMATIC Manager, insert a Process Historian PC Station.
- Open NetPro: Establish the communication connections between all OS Servers and the PH over the Terminal Bus.
- Download the PC Station configurations.
5. Verify Store and Forward Activation:
- In WinCC Explorer on each OS Server, verify that the Process Historian status icon in the notification area displays Active / Connected (Green icon).

Verification

Verify that process data streams into Process Historian and reports generate:
1. Open the Process Historian Management Console:
- Check the System Status: Confirm all connected OS Servers report status Connected / Replicating.
- Check the Active Segment: Confirm that incoming tag counts and message counts increment steadily.
2. Open a web browser on an office PC: Navigate to https://<InformationServerName>/InformationServer.
3. Log in with authorized Windows credentials.
4. Select a standard template (e.g. Trend Report): Select process tags, select a time range of 'Last 24 Hours', and click Execute.
5. Confirm that the report renders high-resolution historical trends identical to the WinCC runtime trend displays.

Limitations and Operational Precautions

Never install Process Historian on an active WinCC OS Server; historian data writing and complex SQL aggregation will exhaust server CPU and disk I/O, destabilizing plant operator screens.
Segregating SQL Data files (.mdf), Transaction Log files (.ldf), and archive destination volumes on separate physical RAID disk arrays is strictly mandatory for performance.
Commercial licensing note: Process Historian and Information Server require dedicated software and tag capacity licenses (e.g. 6ES7652-0...); validate licensing schedules against an authorized Siemens distributor quotation.

Engineer FAQ

Can Process Historian run in a virtualized VMware environment?

Yes. Process Historian and Information Server are officially certified for deployment on VMware vSphere ESXi, provided dedicated CPU cores, reserved RAM, and high-performance SAN storage arrays are allocated.

What happens to data if the Process Historian server crashes?

OS Servers automatically engage Store and Forward mode, caching all historical data in local WinCC database files. Once the PH recovers, all buffered data is automatically backfilled with zero data loss.

Can external third-party software query Process Historian directly?

Yes. Process Historian supports the OpenPCS 7 interface and standard OLE-DB / OPC HDA queries, allowing external MES, ERP, or OSIsoft PI systems to read historical data securely.