I'm an engineering student in Computer science and Automation with a focus in control systems. I'm now doing an internship in an oil refining company in morocco, and I'm about to make a comparative study between APC (advanced process control) vendors.
In the firm, the process is controlled by a Yokogawa's DCS (Centum CS 3000) which offer an OPC (EXAOPC) to allow the communication with higher systems.
My question is : because of technical and financial issues I can't implement each one of the controllers and calculate their profitabilities. So how can I make a comparison between the APC vendors without testing them ?