Festo announced Wednesday that it’s adding the CMMT-AS-S3 servo drive to its portfolio, offering machine builders higher levels of safety while simplifying design, wiring, and certification.
The new model gives OEMs a choice between two safety levels for the CMMT-AS: Basic (S1) and the new Advanced (S3), providing a cost-effective way to meet safety and performance requirements on packaging lines. All CMMT-AS drives are multiprotocol and configurable for EtherNet/IP, PROFINET, EtherCAT, and Modbus TCP.
“It’s surprisingly easy to implement,” said Tom Worsnopp, product manager for electric automation at Festo. “With a few parameter settings in the configurator, the user can activate and validate advanced safety functions in minutes.”
Integrated safety functions
The CMMT-AS drives include safety features directly in the drive, reducing the need for external components and setup time. OEMs can implement safety via hard-wired I/O or over a PROFIsafe network for integration with Siemens safety programmable logic controllers (PLCs). This flexibility allows machine builders to balance simplicity, performance, and cost across a range of machines.
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Festo’s Automation Suite commissioning software lets users select the interface, enter parameters, and activate safety functions. A Validation Wizard, expected in winter 2025, will guide engineers through verification steps and generate safety reports for certification.
Two-tier safety offering
The Basic (S1) version is designed for cost-sensitive machines and provides standard safety functions with fast commissioning through hard-wired connections. Its additional features include:
- Safe Torque Off (STO): Cuts power to the motor to prevent motion
- Safe Brake Control (SBC): Engages the motor brake for vertical or gravity-loaded axes
- Safe Stop 1 (SS1) Type C: Controlled stop before removing power (requires external timer)
- Diagnostic outputs: Safety Trip Alarm (STA) and Standby Alarm (SBA)
The Advanced (S3) version is built for more advanced machines. It integrates additional safety functions, reduces external components, and works with Festo’s EMMT-AS motors with integrated safety encoders. Its additional features include:
- Built-in SS1 timer (no external timer required)
- Safe Stop 2 (SS2): Controlled stop while maintaining servo control
- Safe Operating Stop (SOS): Monitors standstill without cutting power
- Safe Limited Speed (SLS) and Safe Maximum Speed (SMS): Keep motion below defined thresholds, supporting collaborative robots and semi-automatic operations
- Safety Over Network: PROFIsafe over PROFINET enables full control via a single Ethernet cable from a safety PLC
Ease of setup and compliance
Festo designed the CMMT-AS series for simplicity. Each configuration is password-protected through a dedicated safety engineer login to ensure parameters remain locked and traceable after validation. This also supports compliance with the upcoming European Cyber Resilience Act (CRA).
Part of Festo’s safety ecosystem
The CMMT-AS series complements Festo’s broader safety ecosystem, including actuators, motion systems, and control software, designed to improve reliability and reduce risk.
