A view of designed and implemented plant model for level control is shown in the photograph of Fig. 1. It consists of five Fieldbus instruments from different vendors; gauge pressure transmitter (PT_101), magnetic flowmeter (FT_101), temperature transmitter (TT_101), valve positioner (LCV_101), and differential pressure transmitter (LIT_101). Fig. 2 shows its piping and instrument (P&I) diagram.