Experimental validation of PID based cascade control system through SCADA–PLC–OPC and internet architectures

The paper presents the experimental validation procedure of a simple cascade control system through number of architectures, such as SCADA, PLC, OPC and internet. The performance and effectiveness of individual architecture is evaluated on the basis of data rate, rise time, peak time and settling time. In this study, PID is implemented on Micrologix-1200 PLC and RSView-32 SCADA has been used with RSLinx communication software. The PLC–SCADA control loop is implemented with the functionalities such as, real time data analysis, set point modifications, automatic report generation and integration of data with MS-Excel and MS-Access. The enhancement in project data analysis is effectively done through the integration of PLC with Labview. The remote monitoring and control of process parameters is done using NET-ENI. The obtained result proved that the conventional SCADA based control system can be enhanced further more with PLC as well as NI-OPC server significantly.

► Individual architecture is evaluated on the basis of data rate, rise time, peak overshoot and settling time.
► From the obtained results, the SCADA system with PLC shows minimal settling time, peak over shoot and peak time.
► The overall performance of the system is significantly improved and eventually it becomes more stable.
► The experiment also tends to interface PLC based process with NI-OPC server and significant results are obtained.
► The main advantage sensed with this interface mechanism is enablement of changing data rate to desirable range.