Beckhoff Sistema Library Review

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:

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. beckhoff sistema library

[ PL = \textFunction of ( \textCategory, \textMTTFd, \textDC, \textCCF ) ] stConfig

PROGRAM SAFETY_VALIDATION VAR // Emergency Stop safety chain fbEStop : FB_Sistema_Channel; eStop_MTTFd : UINT := 150; // Years per channel eStop_DC : REAL := 0.99; // 99% diagnostic coverage eStop_CCF : UINT := 85; // CCF score ( >=65 = sufficient) eStop_Result : ST_Sistema_Result; END_VAR Use the ST_Sistema_Config structure to define your safety category: stConfig.Category := SISTEMA_CATEGORY.CAT_3

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

// 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 );