The SI system (current pulse system) is a control and automation technology for hard-wired installations. The wide range of functional modules and the logic provided by the wiring enables a wide range of control tasks to be carried out. These include switching electrical consumers (e.g. lights, roller shutters, blinds) depending on the light and time of day, dimming functions for low-voltage and DALI lights, or protecting roller shutters and awnings from wind and rain. These can be supplemented as required with individual, group and central commands. The SI system does not require any PC programming and can therefore be installed conventionally. Since the wiring largely corresponds to controls with relay or contactor circuits, the costs for planning and commissioning are very low. The consistent use of the control and supply voltage of 24 V DC and the strict separation between the protective extra-low voltage and low-voltage side make the components compact, cost-effective and immune to interference. In addition, control cables with a length of up to 100 m allow standard switch programs to be easily connected, even in large buildings. The system is particularly suitable for lighting control. Remote dimmers, the DALI gateway and twilight sensors are available for this purpose. The SIRW rain monitor can be used in the SI system or in conjunction with, for example, installation relays. It detects and signals even short-term rainfall according to the set sensitivity. Properties: precisely adjustable moisture detection, integrated heating, relay for 50 V AC / 2 A, power supply 24 V DC, Installation type: surface-mounted at an angle of approx. 30 degrees to the horizontal, the tips of the sensor surfaces must point downwards, dripping water should be avoided, installation on the SIWH telescopic bracket is recommended, Areas of application: By detecting rainfall, the rain monitor is suitable for controlling, among other things, external blinds, awnings, roof hatches.