The Linear Light4 Link system can incorporate Spacers and Connectors which have inbuilt PIR detectors to improve energy efficiency. Two PIR Control Devices is available to control the system; the 'Controller' offers simple remote on, off and dimming modes. The 'Programmer' offers sophisticated control of various operations including presence detection and daylight linked illumination. PIR Spacers and Connectors are suitable for use with digital dimming gear types F, G and V, a Digital Serial Interface is not required. A single PIR can control up to four Fluorescent Modules.