Programmable logic controllers are resistant computers designed to control a variety of industrial processes. These controllers are the “brains” of fully automated production lines and complex standalone devices. Based on default program parameters and signals from external devices (e.g. sensors), the controller performs an evaluation, sends signals to external devices (e.g. frequency converters) and adjusts the process. PakMarkas distributes innovative Siemens controllers, from the simplest LOGO! modules up to the advanced SIMATIC S7-1500 series.