Optimizing Machine Safety with the Safety Integrated Function of S7-1200

Machine safety is essential in industrial automation to protect personnel, equipment, and ensure regulatory compliance. The SIMATIC S7-1200 offers Safety Integrated functions, making it possible to implement reliable, flexible safety measures within the PLC. This guide covers the key aspects of using the S7-1200 for machine safety, from configuring safety blocks to best practices for setup and testing.

Contents

1. Introduction to Safety Integrated Functions in S7-1200
2. Key Components for Safety Configuration
3. Configuring Safety Blocks in TIA Portal
4. Testing and Monitoring Safety Functions
5. Best Practices for Machine Safety with S7-1200

1. Introduction to Safety Integrated Functions in S7-1200

The S7-1200’s Safety Integrated feature supports advanced safety functions like emergency stop, safe speed monitoring, and door interlocks. By programming safety functions directly within the PLC, you can simplify system design, ensure compliance with safety standards (such as ISO 13849), and enhance overall system safety. Safety functions are certified for up to SIL 3 and PL e, suitable for high-demand applications.

2. Key Components for Safety Configuration

Several key components are essential for configuring safety functions within the S7-1200 system

• Safety PLC: The S7-1200 series includes safety CPUs that support safety applications in addition to standard control.
• Safety I/O Modules: Safety I/O modules connect directly to safety devices like emergency stop buttons, light curtains, and door switches, ensuring reliable data exchange.
• Fail-Safe Program Blocks: Safety programming uses specific blocks such as F-CALL and F-Contact for implementing safety logic, making it easy to integrate with standard program blocks.
• TIA Portal Safety Advanced: This add-on to TIA Portal allows for the programming and configuration of safety functions.

3. Configuring Safety Blocks in TIA Portal

Configuring safety blocks within TIA Portal requires setting up safety-specific logic using fail-safe function blocks

1. Create a New Safety Program: In TIA Portal, create a new safety program section. This ensures that safety functions are separate from standard functions, simplifying testing and troubleshooting.
2. Use Safety Function Blocks (F-Blocks): Add blocks like F-CALL (Fail-Safe Call) and F-Contact to handle specific safety operations such as emergency stops or two-hand controls.
3. Set Safety Parameters: Configure parameters such as reaction time and fault response behavior within each block. Define these based on your application’s specific safety requirements.
4. Assign Safety I/O: Link your safety I/O modules to the safety blocks, connecting them to physical safety devices. TIA Portal allows you to simulate inputs to test the safety response before deploying the program.

4. Testing and Monitoring Safety Functions

Testing is critical to ensure safety functions perform as expected under all operating conditions

• Simulate Safety Events: Use TIA Portal’s safety simulation features to simulate safety events (e.g., triggering an emergency stop) and verify the correct response.
• Monitor Safety Data in Real-Time: Watch Tables in TIA Portal allow you to monitor real-time values from safety I/O and safety blocks, ensuring that inputs and outputs respond appropriately.
• Log Safety Events: Use diagnostic features to log and track safety events, allowing you to identify potential issues in the safety setup.

5. Best Practices for Machine Safety with S7-1200

1. Separate Safety and Standard Logic: Keep safety functions in a dedicated safety program section to make it easier to identify and troubleshoot issues without affecting standard operations.
2. Regularly Inspect Safety Devices: Safety devices such as emergency stop buttons, light curtains, and interlocks should be tested and inspected periodically to ensure proper function.
3. Use Redundant Safety I/O: For high-risk applications, consider using redundant safety I/O to enhance reliability and reduce the risk of single-point failures.
4. Train Personnel on Safety Procedures: Ensure that operators and maintenance staff are familiar with safety features, testing methods, and how to respond to safety events.
5. Document Safety Protocols and Events: Maintain a record of safety protocols, configurations, and events to support regulatory compliance and make future troubleshooting more efficient.

Conclusion

Implementing safety functions with the SIMATIC S7-1200’s Safety Integrated features enhances machine safety, reduces risk, and simplifies compliance with safety standards. By configuring safety blocks in TIA Portal, testing with simulations, and following best practices, you can create a robust safety setup that protects both personnel and equipment. Regular monitoring and training further ensure that safety functions operate as intended, providing a secure and reliable automation environment.