Glossary · Protective devices and interlocks
Blanking
German: Blanking
In machine safety, blanking is a configured allowance for defined objects or areas within a protective sensing field, so that these objects do not trigger a stop. Fixed blanking ignores a fixed area; floating blanking ignores an object of limited size anywhere in the field.
- Machine safety
- Risk assessment
In one sentence
Blanking lets a light curtain ignore defined objects in its field, such as a conveyor or workpiece, but it creates gaps that change the minimum distance.
Example
A light curtain at a press brake uses fixed blanking for the beams covered by a fixed part of the tooling, and the resulting reduced resolution is used in the minimum distance calculation.
How it applies
- Machine safety: Blanking reduces the effective detection capability of the device. The larger resolution must be used in the minimum distance calculation, and blanked areas that a person could reach through must be covered by guards.
- Configuration: Blanking is a safety parameter. Access to it must be restricted, and changes must be documented and verified under configuration control.
- Evidence: Record which beams or which object size are blanked, why, and the resulting resolution in the validation records.
- Technical documentation: The instructions should state that blanking may only be changed by authorized persons and that the minimum distance must be rechecked afterward.
Blanking vs. muting
Blanking permanently ignores part of the field while the device stays active. Muting temporarily suspends the whole protective function under monitored conditions.