Résumé: The application of computers for controlling process units is now about tell years old. The applications have progressed from the experimental stages of early development to a well-established (economically speaking) control practice. This has not been without some anxious moments and a few outright failures. These have not been forgotten, but current successes are proving beyond any doubt that digital conputers are capable of generating an attractive economic return on the investment required for their installation. This paper has three objectives: first, to acquaint those outside the process industries of the general process control problem in order that they may appreciate some of the requirements imposed on a control computer; second, to describe the computer hardware normally considered for process control; third, to present the general philosophy of the real-time software systems required for process control.

Langue: Anglais