The main goal for our study is the design, implementation, and empirical test of the physical and software model of an OPC-based SCADA system comprising multiple industrial controllers of various commercial brands. In this study, an electro-pneumatic press prototype was prepared with four different PLCs, an open-source controller and an operator panel which have different industrial communication protocols. Each sub-task of the pressing unit was assigned to different industrial controllers, and the network infrastructure of the SCADA system was created with a star topology and taken into operation. The connectivity and interoperability for the designed networked system comprising significant number of devices with different industrial communication protocols was effectively provided. OPC-based SCADA system was tested in runtime mode and the controllers successfully talked to each other through the system. The hardware and software structural details, possibl1e malfunctions and data transmission speeds of the system were analyzed and shared.