It is not much possible for controllers such as PLC (Programmable Logic Controller) and DCS (Distributed Control System) used in the industry to solve complex systems. On the contrary, Matlab/Simulink provides advantages with the solutions it offers in the complex systems. It is highly significant that PLCs have a real-time communication with Matlab to solve this kind of complex systems. For industrial automation, interoperability standard OPC (OLE for process control) plays the role of a bridge between Matlab/Simulink and PLC and enables data exchange between them.  On the other hand, Fuzzy Logic provides advantage in solving complex systems. There are two inputs in this research. Temperature and relative humidity data is transferred to Matlab/Simulink via OPC by PLCs. Based on the temperature and relative humidity felt depending on the temperature, the percentage of fan speed is calculated by using Fuzzy controller in Matlab/Simulink and transferred to PLC via OPC and the required physical output connected to PLC is activated. This system shows how fast the processes which are complex in PLC can be solved with Matlab/Simulink.  A complex system developed in Matlab/ Simulink can be automatically converted to any microcontroller code.  The PLC used in industry can communicate with this microcontroller as well and obtain the desired output in the best way possible. Nowadays, Artificial Intelligence develops day by day and such a system gains even more importance.