It is notmuch possible for controllers such as PLC (Programmable Logic Controller) andDCS (Distributed Control System) used in the industry to solve complex systems.On the contrary, Matlab/Simulink provides advantages with the solutions itoffers in the complex systems. It is highly significant that PLCs have areal-time communication with Matlab to solve this kind of complex systems. Forindustrial automation, interoperability standard OPC (OLE for process control)plays the role of a bridge between Matlab/Simulink and PLC and enables dataexchange between them.  On the otherhand, Fuzzy Logic provides advantage in solving complex systems. There are twoinputs in this research. Temperature and relative humidity data is transferredto Matlab/Simulink via OPC by PLCs. Based on the temperature and relativehumidity felt depending on the temperature, the percentage of fan speed iscalculated by using Fuzzy controller in Matlab/Simulink and transferred to PLCvia OPC and the required physical output connected to PLC is activated. Thissystem shows how fast the processes which are complex in PLC can be solved withMatlab/Simulink.  A complex systemdeveloped in Matlab/ Simulink can be automatically converted to anymicrocontroller code.  The PLC used inindustry can communicate with this microcontroller as well and obtain thedesired output in the best way possible. Nowadays, Artificial Intelligencedevelops day by day and such a system gains even more importance.