Sistema Library — Beckhoff
[ PL = \textFunction of ( \textCategory, \textMTTFd, \textDC, \textCCF ) ]
PROGRAM Main VAR fbSistema_PLr : FB_Sistema_PLr; // For required PL calculation fbSistema_EStop : FB_Sistema_Channel; rRequiredPL : SISTEMA_PL; eStopResult : ST_Sistema_Result; bMachineAllowed : BOOL; END_VAR // Calculate Required PL based on risk assessment fbSistema_PLr( Severity := SEVERITY.SEVERE, // S2 Frequency := FREQ.LESS_THAN_1_HOUR, // F2 PossibilityOfAvoidance := AVOID.IMPOSSIBLE // P2 ); rRequiredPL := fbSistema_PLr.PLr; // Returns PLr = e beckhoff sistema library
This article provides an exhaustive deep dive into the Beckhoff Sistema Library—what it is, why it matters, how to implement it, and how it revolutionizes safety engineering from design to validation. 1.1 Defining the Core Concept The Beckhoff Sistema Library (often referenced under the TwinCAT 3 function Tc3_Sistema ) is a software library that allows safety engineers to perform Performance Level (PL) and Safety Integrity Level (SIL) calculations directly within a Beckhoff TwinCAT 3 project. [ PL = \textFunction of ( \textCategory, \textMTTFd,
Introduction: The Convergence of Automation and Safety Certification In the world of industrial automation, two forces are increasingly intertwined: high-performance machine control and strict functional safety compliance . For engineers using Beckhoff’s TwinCAT 3 software, bridging this gap traditionally meant manual calculations, external safety validation tools, and double-checking Parameter (P) values against complex standards like ISO 13849-1. It brings the federally recognized SISTEMA (Safety Integrity
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) Call the function block cyclically or on-demand:
// Validate Emergency Stop achieves PL e fbSistema_EStop( Enable := bMachineRunning, Config := (Category := CAT.4, MTTFd_Channel_A := 150, MTTFd_Channel_B := 150, DC_Avg := 0.99, CCF_Score := 80), Result => eStopResult, bCalculate := bSafetyTestTrigger );
Enter the . This specialized library, integrated into the TwinCAT 3 environment, represents a paradigm shift. It brings the federally recognized SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) calculation core directly into the PLC programming workflow.
