The consistently modular design of LOGO! makes it extremely flexible. A wide range of modules allows individual expansion of LOGO! to 24 digital inputs, 16 digital outputs, 8 analog inputs and 2 analog outputs! Communications modules are also available for AS-Interface and KNX (Instabus network for building automation). Now it is also possible to use the analog output module to solve simple closed-loop control tasks. Heating and cooling systems can be designed with the RTD PT100 module using special functions for PI control, ramp response and analog multiplexing.