Safety Integrated Control of SINAMICS S120 with S7-1500 F-CPU via PROFIsafe
This application example explains how to control the Safety Integrated functions of a SINAMICS S120 drive using a SIMATIC S7-1500 Fail-Safe CPU via PROFIsafe communication, enabling safe motion monitoring and controlled stopping behaviour in industrial machines.
Application Overview
The solution demonstrates the interaction between:
- SINAMICS S120 drive safety functions
- SIMATIC S7-1500 F-CPU safety program
- PROFIsafe communication for exchanging safety-relevant data
Safety-related signals between the controller and drive are transmitted through PROFIsafe telegrams to ensure deterministic and certified safety communication.
Implemented Safety Functions
The example focuses on configuring and testing several safety-integrated functions according to industrial safety standards:
✔ Safe Torque Off (STO)
Safely disconnects motor torque to prevent unintended restart.
✔ Safe Stop 1 (SS1)
Initiates monitored braking and then activates STO after a defined delay.
✔ Safely-Limited Speed (SLS)
Monitors that the motor does not exceed a defined safe speed during service operations.
✔ Safe Operating Stop (SOS)
Maintains standstill monitoring while keeping the drive under closed-loop control
These functions are implemented in accordance with DIN EN 61800-5-2 safety standards for drive systems.
System Architecture
Typical hardware configuration includes:
- SIMATIC S7-1511F Fail-Safe Controller
- SINAMICS S120 drive with Control Unit CU320-2 PN
- Safety I/O modules and encoder feedback devices
- TIA Portal with STEP 7 Safety Advanced engineering tools
Communication via PROFIsafe
Safety-relevant communication is implemented using PROFIsafe telegrams that exchange:
An additional safety information channel allows the controller to evaluate safety states and respond within defined delay times.
Control Logic Concept
The fail-safe PLC program:
- Processes emergency stop and safety door signals
- Activates SS1 when an emergency stop is triggered
- Enables SLS during service mode to allow reduced-speed motion
- Applies SOS to safely maintain a standstill during intervention
The PLC must react dynamically to selected safety functions—for example, reducing velocity when SLS is active or halting motion when SOS is triggered.
Engineering Workflow in TIA Portal
Implementation includes the following key steps:
1️⃣ Configure SINAMICS S120 hardware and detect topology in Startdrive.
2️⃣ Add PROFIsafe telegrams and safety communication channels.
3️⃣ Parameterise Safety Integrated functions (SS1, SLS, SOS).
4️⃣ Create F-program blocks to control safety behaviour.
5️⃣ Monitor the safety information channel and react in the user programme.
Typical Industrial Use Cases
This application is ideal for:
- Retrofit projects upgrading to PROFIsafe-based architectures
- Machine safety systems requiring controlled stopping
- Robotic or motion platforms with operator access zones
- Automotive and manufacturing production lines
- High-performance motion applications needing SIL-compliant safety
Key Benefits
✔ Integrated functional safety directly inside the drive system
✔ Certified communication using PROFIsafe
✔ Reduced external safety wiring and hardware complexity
✔ Flexible response depending on machine operating mode
✔ High availability while maintaining operator protection
