SIRIUS ACT Pushbuttons & Indicator Lights Siemens SIRIUS ACT Pushbuttons and Indicator Lights comprise a modular system of pushbuttons and indicator lights for front-plate mounting and rear-mounted electrical modules. Thanks to the SIRIUS ACT with PROFINET, commanding and signaling devices can be connected directly via PROFINET to the controller and HMI devices – including safety functions. Siemens SIRIUS ACT simplifies engineering and commissioning by the TIA Portal.