The Beckhoff SISTEMA Library represents the modernization of functional safety engineering. By embedding safety validation data directly into the control program, Beckhoff has streamlined the path from design to certification. For automation engineers, mastery of this library is essential for delivering efficient, compliant, and robust safety systems in an Industry 4.0 environment. It transforms safety compliance from a retrospective paperwork exercise into an integrated engineering discipline.
Introduction
The Beckhoff TwinCAT 3 System Library is a comprehensive software library developed by Beckhoff Automation, a leading provider of automation technology. The library is part of the TwinCAT 3 software suite, which is widely used in industrial automation, process control, and other fields. This paper provides an overview of the Beckhoff TwinCAT 3 System Library, its features, and its applications.
Background
Beckhoff Automation was founded in 1980 in Verl, Germany. The company has since become a global leader in automation technology, providing innovative solutions for various industries, including automotive, aerospace, food and beverage, and more. In 2003, Beckhoff introduced the TwinCAT software suite, which revolutionized the automation industry with its integrated development environment (IDE) and PLC (Programmable Logic Controller) capabilities.
TwinCAT 3 System Library
The TwinCAT 3 System Library is a powerful software library that provides a wide range of functions and features for developing automation applications. The library is based on the .NET framework and offers a comprehensive set of APIs (Application Programming Interfaces) for C++, C#, and other programming languages.
The System Library includes various modules and classes that enable developers to create sophisticated automation applications. Some of the key features of the library include:
Architecture
The TwinCAT 3 System Library is built on a modular architecture, which allows developers to easily integrate individual modules and classes into their applications. The library consists of several layers, including:
Applications
The Beckhoff TwinCAT 3 System Library is widely used in various industries, including:
Benefits
The Beckhoff TwinCAT 3 System Library offers several benefits to developers and users, including:
Conclusion
The Beckhoff TwinCAT 3 System Library is a comprehensive software library that provides a wide range of functions and features for developing automation applications. The library's modular architecture, high-performance functions, and flexibility make it an ideal choice for developers and users in various industries. With its wide range of applications and benefits, the TwinCAT 3 System Library has become a leading software library in the automation industry.
Future Developments
Beckhoff Automation continues to develop and expand the TwinCAT 3 System Library, adding new features and functions to meet the evolving needs of the automation industry. Future developments are expected to include:
As the automation industry continues to evolve, the Beckhoff TwinCAT 3 System Library is expected to remain a leading software library, providing developers and users with a comprehensive set of functions and features for developing innovative automation applications.
Here’s a structured, critical review of the Beckhoff System library (Tc2_System) — which is often what users mean when they refer to the “sistema” library (from the Italian/Spanish word for “system”).
Attention: The MTTFd_Channel_A input expects years (per ISO 13849-1 standard). For electronic components with very high MTTFd (e.g., 10,000 years), the library caps the value at the maximum level (2500 years + high value = "high"). beckhoff sistema library
The library directly supports Categories B, 1, 2, 3, and 4 from ISO 13849-1. You select the architecture type via an input enumeration:
//Example declaration in TwinCAT 3 ST
PROGRAM MAIN
VAR
fbSistemaSafety : FB_Sistema_Channel;
stConfig : ST_Sistema_Config;
stResult : ST_Sistema_Result;
END_VAR
The classic problem in PLC programming: you have 20 steps in a process. In ladder logic, this often translates to 20 rungs with latching coils and interlocking contacts. In Structured Text, it becomes a CASE statement inside a loop. However, these methods lack formal rigor for handling parallel branches, skips, or holds.
FB_Step and FB_Transition offer a solution:
By linking these blocks, you build a formal step/transition diagram. The library handles the enabling/disabling of steps, ensuring only one sequence of steps is active at a time. This eliminates race conditions common in hand-coded sequences.
| Aspect | Rating (1–5) | |--------|---------------| | Reliability (if used correctly) | ⭐⭐⭐ | | Real-time safety | ⭐⭐ | | Documentation | ⭐⭐ (outdated examples) | | Security | ⭐ | | Modern compatibility | ⭐ (deprecated) |
Conclusion:
It’s a necessary evil for legacy systems, but avoid for new development. Use Tc3_System and dedicated libraries (Tc3_File, Tc3_EventLogger) for robust, real-time-safe applications.
If you have a specific use case (e.g., reading a config file once at boot, or monitoring CPU load), I can give you a safe implementation example.
The Beckhoff SISTEMA Library is a digital data collection provided by Beckhoff to support machine safety evaluations using the SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) utility. Purpose and Functionality
Safety Evaluation: The library is used to model and evaluate safety functions under the DIN EN ISO 13849-1 standard.
Reliability Data: It contains product-specific reliability values—such as MTTFdcap M cap T cap T cap F sub d (Mean Time To Dangerous Failure), B10dcap B 10 d
, and diagnostic coverage—required to calculate the achieved Performance Level (PL) of a safety function.
Workflow Integration: Engineers import these manufacturer-provided libraries directly into the SISTEMA software to avoid manual data entry and ensure accurate safety calculations for TwinSAFE components. Access and Resources
Download: The library files (typically in .slb or .xml format) are hosted on the Beckhoff Download Server under the TwinSAFE documentation section.
TwinSAFE Context: While the SISTEMA library is used for offline calculation, the actual safety logic is developed within the TwinCAT environment using certified safety function blocks.
Support: Detailed technical information and manuals for Beckhoff products, including safety components, can be found in the Beckhoff Information System (Infosys). download/document/automation/twinsafe/SISTEMA - Beckhoff
Beckhoff provides a dedicated SISTEMA library to simplify the process of evaluating safety-related control systems. This tool bridges the gap between Beckhoff's TwinSAFE hardware and the industry-standard SISTEMA software, ensuring that machine builders can easily verify compliance with international safety standards like ISO 13849-1. What is the SISTEMA Software?
SISTEMA (Safety Integrity Software Tool for the Evaluation of Machine Applications) is a free utility developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA). It helps developers and testers calculate the Performance Level (PL) of safety functions. By automating the mathematical complexity of ISO 13849-1, it reduces the risk of manual calculation errors. The Role of the Beckhoff SISTEMA Library
The Beckhoff SISTEMA library is a structured data file (typically in .slb or .xml format) containing all relevant safety parameters for Beckhoff TwinSAFE components. Instead of manually entering technical data for every digital input, logic terminal, or drive, users can import this library directly into the SISTEMA software. Key data points included in the library: MTTFd (Mean Time to Dangerous Failure) B10d values for electromechanical components DC (Diagnostic Coverage) PFHd (Probability of dangerous Failure per Hour) Key Benefits for Engineers
Using the official Beckhoff library offers several advantages during the design and certification phases of a project:
Time Efficiency: You can drag and drop components into your safety project rather than hunting through data sheets for specific safety values. The Beckhoff SISTEMA Library represents the modernization of
Accuracy: Because the data comes directly from Beckhoff, you are guaranteed to use the most current, manufacturer-verified safety values.
Standardized Documentation: The reports generated by SISTEMA using Beckhoff data are widely accepted by regulatory bodies and safety auditors.
Comprehensive Coverage: The library includes data for the entire TwinSAFE ecosystem, from EL series EtherCAT Terminals to integrated safety in AX5000 servo drives. How to Use the Beckhoff SISTEMA Library
The workflow for integrating Beckhoff components into your safety evaluation is straightforward:
Download the Library: Visit the Beckhoff website and navigate to the "Documentation" or "Download" section to find the latest SISTEMA library file.
Import to SISTEMA: Open the SISTEMA software, go to the "Libraries" menu, and select "Import." Point the software to the downloaded Beckhoff file.
Build the Safety Function: In your SISTEMA project, create a new Safety Function (SF). You can then pull Beckhoff components from the library into the "Subsystems" or "Elements" tabs.
Calculate PL: The software will automatically pull the PFHd or MTTFd values and calculate the total Performance Level achieved by your hardware chain. Bridging TwinSAFE and ISO 13849-1
Beckhoff’s TwinSAFE technology is designed for modularity. Since safety logic is processed in the EL6910 or similar logic terminals, the architecture often involves multiple distributed components. The SISTEMA library allows you to model these complex relationships—such as a light curtain connected to an EL1904 input terminal which then triggers an STO (Safe Torque Off) on a drive—with high precision.
💡 Ensure you always download the most recent version of the library, as Beckhoff frequently updates their safety data to reflect new product releases and hardware revisions.
If you tell me which specific TwinSAFE components you are using, I can help you identify the specific safety parameters or architecture categories you'll need to configure in SISTEMA.
Combine the library with TwinCAT's Audit Trail feature:
The Beckhoff Tc2_Sistema library is more than just a collection of function blocks; it is a methodology. It moves the PLC programmer from writing imperative "do this, then this" code to designing declarative state and transition systems.
While there is a slight learning curve—especially for those accustomed only to ladder logic—the payoff in code reliability, debugging speed, and team collaboration is immense. For any medium-to-large TwinCAT project, especially those involving complex sequences or compliance with standards like PackML or OMAC, implementing the Sistema library is not just a recommendation; it is a best practice.
By adopting FB_StateMachine for equipment control and FB_StepChain for process sequences, you will reduce commissioning time, eliminate hidden race conditions, and create automation code that stands the test of time. The next time you start a TwinCAT 3 project, do not begin with a CASE statement. Begin by adding the Tc2_Sistema library and drawing your state diagram. Your future self—and the maintenance technician who inherits your code—will thank you.
Further Resources:
This article was written for automation professionals seeking to enhance their TwinCAT development practices. Always consult the official Beckhoff documentation for the latest library versions and syntax.
Beckhoff SISTEMA Library is a digital product database used by engineers to calculate and verify the safety of machine control systems. It is designed specifically for use with
(Safety Integrity Software Tool for the Evaluation of Machine Applications), a free utility provided by the IFA (Institute for Occupational Safety and Health). Beckhoff Automation Why You Need It
When designing a machine, you must prove it meets safety standards like DIN EN ISO 13849-1 Architecture The TwinCAT 3 System Library is built
. Instead of manually searching for reliability data in PDF manuals, the Beckhoff library allows you to: Beckhoff Automation Import Official Data : Instantly load safety-relevant values (such as cap M cap T cap T cap F sub d cap B sub 10 d end-sub , and Performance Levels) for Beckhoff components like TwinSAFE terminals Reduce Human Error
: Drag and drop components directly into your safety calculation project to avoid manual typing mistakes. Generate Compliance Reports
: Automatically calculate the achieved Performance Level (PL) for your entire safety function. Beckhoff Automation How to Use the Library Download the Library : Get the latest version from the Beckhoff Download Finder (typically found under "Software" or "TwinSAFE"). Import to SISTEMA SISTEMA software Navigate to the Library Manager right arrow Manufacturer Libraries
or use the "Add Library" button to select the downloaded Beckhoff file. Build Your Safety Function
: Once imported, search for your specific Beckhoff part number and copy it into your project's "Subsystems" or "Elements". Deutsche Gesetzliche Unfallversicherung - DGUV Key Performance Metrics Included
The library provides the mathematical "DNA" of each component needed for safety calculations: Performance Level (PL)
: The discrete level used to specify the ability of safety-related parts to perform a safety function. Average Frequency of Dangerous Failure ( cap P cap F cap H
: Revised in the latest standards to represent the hourly risk of failure. Mean Time to Dangerous Failure ( cap M cap T cap T cap F sub d : An estimate of the reliability of the component. Beckhoff Automation for the latest library version or a SISTEMA "Cookbook" guide for beginners? TwinSAFE project design | Beckhoff Worldwide
The Beckhoff SISTEMA library provides safety-related characteristic values for Beckhoff's TwinSAFE components, allowing users to model and verify safety functions within the IFA SISTEMA software utility. These libraries are essential for calculating the Performance Level (PL) of machine control systems according to DIN EN ISO 13849-1. Accessing the Library
Direct Download: The libraries are available in the Beckhoff Download Directory under the path /automation/twinsafe/SISTEMA.
Format: The data is typically provided in the VDMA 66413 universal database format, which is a standardized XML format for exchanging safety parameters between manufacturers and analysis tools like SISTEMA.
Download Finder: You can also use the Beckhoff Download Finder by searching for "SISTEMA" or specific hardware component names. download/document/automation/twinsafe/SISTEMA - Beckhoff
Title: The Invisible Backbone: How Beckhoff’s Sistema Library Bridges Safety and Code
In the world of industrial automation, there is a distinct divide between two types of engineers. On one side, you have the control engineers, fluent in the logic of IEC 61131-3, PLCs, and real-time motion. On the other, you have the safety engineers, guardians of human life, who speak the language of ISO 13849-1, Performance Levels (PL), and reliability data.
Historically, these two worlds communicated through stiff requirements documents and static PDFs. But in the Beckhoff ecosystem, a powerful, often underappreciated tool has dissolved that barrier: the Sistema Library.
The most widely adopted component of the Tc2_Sistema library is arguably FB_StateMachine. This block implements the PackML-inspired state model, a standard defined by OMAC (Organization for Machine Automation and Control).
A typical machine state model includes:
FB_StateMachine provides a robust framework for these states. You do not program how to switch states; you simply call the Start, Stop, Hold, Abort, or Reset commands. The block checks if the transition is legal (e.g., you cannot Hold from Aborting) and outputs the current state.
Integration example:
// Instantiate the state machine fbMachineState : FB_StateMachine;// In your main loop fbMachineState( bStart := bUserStartButton, bStop := bUserStopButton, bAbort := bEmergencyStop, bReset := bUserReset, bHold := bUserHold, // ... other commands );
CASE fbMachineState.eState OF STATE_IDLE: // Prepare machine, turn on ready light STATE_RUNNING: // Call the step chain logic fbMyStepChain.Execute(); STATE_HELD: // Stop motion but keep power STATE_ABORTED: // Cut power, show error END_CASE