Finger Protection
Typical IFM guidance uses 14 mm resolution where finger detection is required. The actual safety distance must be calculated for the machine.
ifm · Functional Safety
ifm Safety Light Curtains & Light Grids
Use non-contact optoelectronic protection where operators need access to a hazardous area without a physical guard blocking the opening. Selection must account for required safety level, resolution, protected height, range, machine stopping time and safety distance.
Type 2 / Type 4 routesFinger · hand · bodyM12 connectionMuting / blanking routes
Protection types
Resolution defines what the light curtain is intended to detect
Light curtains use closely spaced beams for finger/hand/body-part protection; light grids use fewer, more widely spaced beams for body access protection.
Hand Protection
30 mm resolution is a common IFM route for hand protection where the application and calculated safety distance permit it.
Body Protection / Light Grids
Two-, three- or four-beam light grids are used for body access detection, with beam spacing and protected height selected for the application.
Machine applications
Non-contact protection without a physical door across the opening
Light curtains are effective only when bypassing or reaching around the protective field is prevented by the complete machine design.
Robot cells
Access prevention or perimeter guarding around automated cells and work areas.
Presses & saws
Protect operator access while allowing material handling; floating blanking may be relevant for defined feed processes.
Production lines
Protect open access points where a physical guard would obstruct normal material or operator flow.
Material transfer / muting
Muting can temporarily bypass the safety function for authorised material passage when the complete muting architecture is correctly engineered.
Selection matrix
Select by body part, risk and geometry
Current IFM global pages include Type 2/SIL 1 and Type 4/SIL 3 routes; exact availability must be checked for the selected regional product range.
| Protection need | Typical IFM route | Resolution / beam spacing | Engineering checks |
|---|---|---|---|
| Finger detection | Safety light curtain | 14 mm typical | Stop time, safety distance, protected height, range |
| Hand detection | Safety light curtain | 30 mm typical | Reach-through risk, safety distance, machine cycle |
| Body / perimeter access | Safety light grid | 2/3/4 beams; 500/400/300 mm spacing routes | Access path, bypass routes, range |
| Material transfer | Muting architecture | Application dependent | Muting sensors, sequence, timing, feedback, restart |
| Material present in field | Blanking route | Application dependent | Permitted beams, object geometry, residual protection |
Optoelectronic protection
The sensor is only one part of the protective function
A transmitter and receiver create multiple infrared beams. Interruption causes the safety outputs to change state so the machine safety system can stop or prevent hazardous motion. The required distance from the hazard depends on stopping performance and application geometry.
Type 2Lower safety category route where permitted by the machine risk assessment.
Type 4Higher fault-monitoring architecture; IFM documents variants up to SIL 3 / PL e.
Protected heightThe safeguarded beam area, not simply the overall sensor housing length.
RangeDistance between transmitter and receiver, influenced by product mode and environment.
Safety-distance warning: Never place a light curtain based only on available mounting space. Machine stopping time, approach speed, resolution, reach-over/reach-through possibilities and the relevant standard must be used to determine the protective distance.
Requirement capture
Inputs required to select the correct light curtain or grid
The exact OY variant follows from the machine safety function and geometry.
HazardMachine motion, access point and required protective function.
Target safety levelRequired Type / PL / SIL from the safety assessment.
ResolutionFinger, hand or body protection requirement.
Protected heightOpening dimensions and height to be protected.
RangeTransmitter-to-receiver distance and environmental conditions.
Stopping timeMeasured/calculated machine stop time for safety-distance calculation.
Special functionsMuting, blanking, washdown or other application-specific needs.
Safety logicRelay/controller, reset/restart and downstream safe outputs.