SINUMERIK ONE PLC Basic Program Plus – Modular Machine Control Architecture
This application example demonstrates how to create a modular and scalable PLC software architecture for SINUMERIK ONE using the PLC Basic Program Plus integrated with SIMATIC S7-1500 and engineered in TIA Portal.
The concept focuses on reusable code, reduced complexity, and easy machine scalability across different configurations.
Application Overview
With SINUMERIK ONE, the SIMATIC S7-1500 PLC is fully integrated into the CNC environment, allowing modern PLC programming methods such as symbolic addressing, optimised block access, and software units to be used directly within CNC applications.
This enables a unified engineering workflow between CNC, PLC, and HMI inside TIA Portal.
Modular Software Architecture Concept
The example introduces a modular machine-oriented structure where:
- Each machine function is implemented as independent PLC modules (FBs/FCs).
- Modules communicate through a central Machine Data Model data block.
- Functions remain decoupled, allowing independent development and testing.
This approach simplifies scaling, maintenance, and reuse across multiple machine types.
Machine Data Model (Core of the Design)
The Machine Data Model contains all operational and status data exchanged between NC, PLC, and machine control panel.
- Centralized structured data keeps large projects manageable.
- New modules can be added without affecting existing ones.
This structure enables clear separation of machine components such as axes, channels, and operating modes.
Program Structure Strategy
The PLC program is divided into compact logical modules grouped into aggregations, each representing a machine function (e.g., axis control).
Advantages of this design include:
✔ Easier diagnostics and maintenance
✔ Reusable blocks across machines
✔ Scalability for optional configurations
✔ Reduced interdependencies between modules
The PLC program is divided into compact logical modules grouped into aggregations, each representing a machine function (e.g., axis control). SINUMERIK ONE PLC Basic program…s
Use of Software Units in TIA Portal
Software Units are used to divide the PLC project into independent functional areas that can be edited and loaded separately.
Example units include:
- UnitCycle – controls PLC execution cycle
- UnitMachineFunctions – implements machine modules
- UnitToolManagement – handles tool changer logic
- UnitLibrary / UnitAlarming – shared functions and alarms
This improves modularization and supports parallel engineering.
PLC Program Cycle Integration
The execution sequence is organized using standard organization blocks:
- OB100 (Startup) – initializes NC-PLC data exchange
- OB1 (Main Cycle) – executes machine modules
- OB40 (Interrupt) – processes CNC-related events
The main cycle is further divided into:
- PostMain → alarm handling and registration completion
- PreMain → data synchronization
- CycleMain → module execution
Example Machine Configuration Modeled
The sample system represents a CNC machine, including:
- One operating mode group
- Multiple channels and machine axes
- Machine control panel (MCP) and operator interfaces
- Tool management and alarm handling functions
Key Engineering Goals Achieved
The application emphasizes:
✔ Code reusability across machine families
✔ Easy expansion for optional machine features
✔ Compliance with SIMATIC programming style guidelines
✔ Simplified troubleshooting and monitoring
Practical Benefits for Machine Builders
This architecture is ideal for:
- CNC machine OEM development
- Modular machine platforms
- Standardizing PLC structures across product lines
- Scaling machines with optional technology packages
- Digital manufacturing and high-flexibility production
