How to Connect Control Panels, Fire Detectors, and Peripherals

A System Overview

We prepared for you a system overview. It depicts how you can connect Desigo™ Fire Safety control panels, fire detectors, and peripheral devices.


  • The FCnet/SAFEDLINK connects up to 16 networkable control panels and fire terminals.

  • The distance between two panels can be up to 3300 ft. With a repeater or optical interface module, the distance can be extended.


  • All detectors are placed on the FDnet, a modern, multipurpose detector bus system that is connected to a networkable control panel.

  • The detectors also communicate and get their power supply directly via the FDnet – without needing additional cabling.

RS485 loop

  • The RS485 loop is connected to the serial interface of the RS485 class A module.

  • Devices that can be connected via the RS485 loop: remote display, remote terminal, and remote peripheral module.

  • The class A circuit can have a maximum length of 1650 ft.

  • The class B circuit can have a maximum length of 3300 ft.

  • A maximum of 8 devices can be connected.

Notification Appliance Circuit

  • The NAC circuit (Notification Appliance Circuit) is a supervised circuit for connecting horns, strobes, loudspeakers, sprinkler valves etc.

  • The connected devices also receive their power supply via the NAC circuit.

  • One class A or two class B circuits can be realized.

  • The NAC circuit can be extended using an additional NAC module.

Loop installation

  • The FDnet and the FCnet/SAFEDLINK are implemented as a loop.

  • This increases fire safety: In case a bus has been interrupted at one point or a short circuit has occurred, a message is simply redirected the other way.

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