Compact, RFID high coded interlocks for safe access to machinery providing the highest level of safety up to Cat 4, SIL 3, PLe. For guard locking use Atom and for non contact gate switches use FRNK.

In line with guidance in ISO 14119, our compact solutions have high coded, uniquely paired actuators to reduce the possibility of defeat, their compact size and multiple mounting orientations make them simple to mount out of reach for further peace of mind. Designed for ease of install, they come pre-wired with quick disconnects and require just 2 mounting points each on the device and the actuator.


Atom – compact guard locking:
Guards which drop or become misaligned or even very tight spaces are no problem for the Atom. The clever tongue design has very high misalignement capability which works down to hatches as small as 150mm opening radius. Suitable for harsh environments due to open head meaning dust and dirt is pushed out of the unit during operation and means it is easy to maintain. OSSD dual channel safety channels with internal fault detection mean the devices can be daisy chained together to minimise wiring while retaining maximum risk reduction. A handy LED on the device shows what state the device is in, guard open, guard closed or a fault.

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Key benefits

High-coded RFID actuator

Versatile high misalignment

Compact - Perfect for small guards

  • Atom can be easily rotated for installation in all different orientations with just two fixings on the interlock.
  • The Atom actuator can be combined with Fortress’ unique mounting kits for a variety of ergonomic access solutions.
  • Robust design results in a single device being required to achieve the highest safety performance levels.
  • Range of pre-wired connector options.
  • 3rd party approved for applications requiring high reliability.
  • Suitable for applications up to SIL3 Cat.4 PLe
  • 24V control voltage
  • Variants offered in robust metal alloy enclosures
  • Hosts Over 4,000,000,000 unique codes to prevent interlock defeat
  • Supports OSSD safety channels to minimise cabling requirements
  • Safety on guard only and safety on guard locking solutions with power to lock (SOG) and power to unlock (SOG & SOGL).
  • IP65, IP67, & IP69
  • High actuator retention forces of 8,000N
  • Enables padlockable head during guard opening to prevent unexpected restart.
  • Third party TUV approved.

A Fortress representative can help configure a solution to the exact requirements of an application. This range hosts a standard subset of products in addition to a wider extensive range to select from.

Atom comes with 12 standard varieties; use our configuration tool to select the variant for you here.

All downloadable assets

To have access to the Atom technical information, please login to

  • Select from our range of high-coded compact yet robust interlocks using our Atom selector
  • Use our Datasheets / drawing generators to create technical files, datasheets, and CAD for your selected product.
  • Convert your unique ITM number into a Fortress part number using our Reference tool
  • Calculate the performance level of your unique safety system using our SISTEMA library
  • Click here for more Fortress Product tools

Access control in manufacturing

Fortress offers the ability to control who can access industrial equipment safely alongside when they can access safely. Data of who, when and where from access events is collated for efficiency analysis.