SAP PI web services integration for high-accuracy boiler testing with secure plant network isolation.
Industry: Manufacturing (Boiler/HVAC)
Quick Facts
| Attribute | Value |
|---|---|
| Application | Boiler test station with SAP PI integration |
| Flow Rates | 3-5 million BTU range |
| Accuracy | 1% of reading |
| PLC Tags | 82 tags per station |
| Recipe Parameters | Up to 24 per test |
| Response Time | 3ms from WCF interface |
| Protocol | Modbus TCP/IP |
| Integrator | Mesa Associates (CAP certified) |
The Challenge
Challenge: Engineer a new boiler test station solution that retrieves test parameters from a remote SAP PI system (Ohio) while maintaining network security and high-accuracy flow measurement.
Specific pain points:
- System must query SAP database using unit serial numbers for specific test parameters
- Production test stands must be separate from SAP PI interface for network security
- High-accuracy flow meters monitoring gas flow (3-5 million BTU, 1% accuracy required)
- Easy to install with recovery files consisting of two or fewer files
- Must be easily expandable
- Need to monitor connection to SAP PI web services
- Budget constraints — other SCADA solutions required expensive server systems with thin manager or ERP integration
Impact: Most SCADA packages reviewed drove project cost out of budget range due to infrastructure requirements for web services access.
The Solution
Architecture
| Tier | Component | Capabilities |
|---|---|---|
| SAP PI | Remote server (Ohio) | Test parameters, recipe database |
| Main Server | Web server with dedicated internet | WCF Test Server, isolated from plant |
| Test Station | FrameworX + Custom DLL | SCADA interface, Visual Studio DLL |
| PLC | Cymon via Modbus TCP/IP | Flow meters, flow switches, sensors |
Data Flow
SAP PI Server (Ohio)
|
Main Server (WCF Test Server)
|
| (3ms response)
|
Test Station (FactoryStudio + DLL)
|
Cymon PLC (Modbus TCP/IP, 82 tags)
|
Flow Meters & Sensors
Security Architecture
- Main web server has dedicated internet access outside plant
- Multiple access to web services without allowing internet to plant floor
- Simple file protocol interface (text files only)
- No special software requirements — simple file sharing via shared drives
- Production test stands separated from SAP PI interface
DLL Integration
| Feature | Implementation |
|---|---|
| Recipe Transfer | One line of code transfers up to 24 test parameters |
| Structure Mimicking | DLL properties structured as FactoryStudio tags |
| Event Procedures | Easily picked up from DLL (.NET compliant) |
| Testing | Robust compliance testing in Visual Studio environment |
| Communication | Windows File API functions, directory change events |
Multi-Station Support
- System designed for multiple stations
- File interface acts as storage buffer for simultaneous requests
- Each station contains FrameworX + embedded DLL
- Real-time updates to operator screens via events
Key Enablers
FrameworX capabilities that made this solution possible:
| Capability | Application |
|---|---|
| Full Visual Studio Compliance | Custom DLL development with .NET integration |
| Low I/O Point Cost | Budget-friendly for 82-tag stations |
| Structured Tag Support | DLL properties mimic tag structures |
| Event Procedures | Real-time screen updates from DLL events |
| Web Services Interface | SAP PI connectivity without expensive infrastructure |
| Simple Recovery | Two or fewer files for project backup |
The Results
Budget Achievement — Full Visual Studio features and low I/O cost kept project within budget
3ms Response Time — Fast data exchange between WCF interface and test stations
Secure Architecture — Plant network isolated while maintaining SAP PI connectivity
Simplified Development — One line of code transfers 24 recipe parameters via DLL structure
External Testing — Heavy lifting in DLL code allows testing outside FactoryStudio in Visual Studio
Scalable Design — Multiple stations supported with file buffer for simultaneous requests
Easy Installation — Simple file sharing via shared drives, no special software required
High Accuracy — 1% reading accuracy maintained for 3-5 million BTU flow measurements
Customer Testimonial:
"Most standard SCADA packages we reviewed had a subset of Visual Studio capabilities or a trimmed down version of VBA. FactoryStudio from Tatsoft was finally selected due to the full Visual Studio compliant features and low I/O point count cost."
— Greg Dixon, Project Manager & CAP Integrator, Mesa Associates
Resources
Download case study: CaseStudy_BoilerTestStation.pdf
This case demonstrates SAP PI web services integration for boiler test stations with secure network isolation and Visual Studio DLL development.
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