Abstract: A system for monitoring and securing a zone associated with a power driven textile machine, which machine includes a part which moves when the machine is in operation in a manner to endanger an individual present in the zone, which system includes a radiation emitting device for producing a beam of directed radiation and for directing such beam along a path coincident with at least one boundary of the zone, a radiation responsive device positioned in the path of the radiation beam for producing an output indication when it is not receiving the directed radiation and a control unit connected to the radiation responsive device for halting movement of the part in response to appearance of the output indication.