Control Loop Performance Improvement for OPC Implementation

The OPC (OLE for Process Control) protocol was developed as a solution which fulfils the requirements of open data integration architecture for industrial control. The OPC standard was primarily not intended for feedback control with real-time requirements. The main complication of this control architecture is the presence of variable time delays. There are several ways to reduce the negative impact of the delays which OPC introduces into the control loop. The Smith predictor turns out to be a simple and effective compensator that rejects the time delays from the control loop.