RDU50 is a room temperature controller with a liquid crystal display from Siemens Building Technologies for heating or cooling systems, with PI control, 0 to 10V output to the actuator, automatic cold/hot conversion, manual cold/hot conversion, operating modes: normal, energy-saving or off, operating mode conversion input, adjustable installation and control parameters, output reverse signal, display of room temperature and optional temperature values, minimum and maximum temperature set value limitation and other features.