Safe series connection
Flexi Loop

Your Benefits

  • Connecting both safety switches and safety sensors with OSSD outputs in series minimizes the amount of wiring and the number of inputs at the safety controller, thus reducing costs.
  • Easy retrofitting of existing machines
  • Simple calculation of the performance level saves time since the Flexi Loop node monitors each sensor individually
  • Quick and easy configuration saves time
  • Ability to be used over long distances increases application flexibility
  • Detailed diagnostic information – who switched and why? minimizes system downtime
  • Seamless system integration and communication with other SICK safety controllers
  • Detailed status information on Flexi Loop components, diagnostic accessories, and safety controller enable quick and easy field diagnostics


Flexi Loop can connect up to 32 safety sensors in series in compliance with the highest performance level PL e. Safety switches and safety sensors with OSSD outputs can be used together, regardless of manufacturer. Detailed diagnostic information is also available for each sensor or switch. Integrated switching signals allow for the use of interlocks, switches, and lamps. All sensors are supplied with voltage directly from the Flexi Loop. Unshielded standard cables are used with M12 male connectors. Ultimately, Flexi Loop can be relied upon for maximum safety. Connecting sensors in series reduces the amount of wiring and the number of safety inputs in the control cabinet. It also provides a comprehensive diagnostic check of all doors, emergency stop pushbuttons, and sensors. In conjunction with Flexi Soft and Flexi Classic, the entire safety application is able to cost-effectively meet customer needs.

At a glance
  • Series connection of 32 sensors with up to 100 m per segment in compliance with performance level PL e
  • Compatible with sensors from all manufacturers
  • Detailed diagnostic information
  • Integrated standard inputs and outputs
  • Voltage supply for sensors is included
  • Unshielded standard cable featuring M12 connectivity
  • IP65 and IP67 enclosure rating
  • Intelligent accessories for field diagnostics and commissioning


Technical overview

  • Technical data overview

    Technical data overview

    Safety levelPL e, SIL3, SILCL3
    Suitable for

    Flexi Classic

    Flexi Soft

    Safety device connection

    For safety sensor with dual-channel OSSD outputs

    For dual-channel equivalent electro-mechanical safety switch (EMSS)

    Structure of a Flexi Loop cascade


    1 ... 32 Flexi Loop nodes

    0 ... ∞ Flexi Loop accessory nodes

    1 Flexi Loop terminator

    Enclosure ratingIP65, IP67
    Ambient operating temperature–25 °C ... +55 °C
All technical data can be found accompanying the individual product