The present article explains a reliable solution regarding the Programmable Logic Controller (PLC) implementation into a security system used to control and monitor a four floor building. The application is split in four different sections: secured access, motion detection, command and monitor elevator and alarm triggering in case of a fire. The PLC integration in management processes is often encountered due to its less surveillance, programs easy update and remote diagnosis accessibility.

Keywords: Programmable logic controllers, LADDER diagram.