To understand the magic of the Beckhoff implementation, we first have to look at the source. SISTEMA (Safety Integrity Software Tool for Evaluation and Machine Application) is a software tool developed by the IFA (Institute for Occupational Safety and Health) in Germany. It is the global gold standard for calculating the safety performance of machinery. It answers the critical question: “Is this safety system reliable enough to prevent injury?”
However, out of the box, SISTEMA is a standalone database. You manually look up components, enter data, and generate a report. It is disconnected from the actual code running the machine.
Use the ST_Sistema_Config structure to define your safety category: beckhoff sistema library
stConfig.Category := SISTEMA_CATEGORY.CAT_3; // Category 3 architecture
stConfig.MTTFd_Channel_A := eStop_MTTFd;
stConfig.MTTFd_Channel_B := eStop_MTTFd;
stConfig.DC_Avg := eStop_DC;
stConfig.CCF_Score := eStop_CCF;
stConfig.Nop := 1; // Number of operations per year (for MTTFd calculation)
The library implements the standard formula for Performance Level:
[ PL = \textFunction of ( \textCategory, \textMTTFd, \textDC, \textCCF ) ] To understand the magic of the Beckhoff implementation,
Where:
The FB_Sistema_Channel function block handles these parameters. The library implements the standard formula for Performance
In the world of industrial automation, the complexity of machine programming has grown exponentially. Modern machines are no longer collections of independent cylinders and motors; they are highly interdependent systems requiring state management, error handling, and coordinated motion. While standard PLC programming (using TIA Portal, RSLogix, or TwinCAT’s standard libraries) provides the building blocks, managing large-scale applications often leads to monolithic, hard-to-debug code.
Enter the Beckhoff Sistema Library (Tc2_Sistema). This powerful, often underutilized library provides a framework for designing robust, reusable, and highly structured control applications. It brings concepts from object-oriented programming (OOP) and state transition logic directly into the IEC 61131-3 environment of TwinCAT 3.
This article will dissect the Beckhoff Sistema Library, exploring its core components, practical applications, and why it should be a staple in your TwinCAT development toolkit.
Once the safety logic is running, the library allows you to calculate DC (Diagnostic Coverage) dynamically based on: