Simulation is an important tool used in the design, testing, and evaluation of process controller designs. Simulation is used to exercise controllers under realistic conditions and thus demonstrate how a controller will perform in the field. The simulator described in this paper is implemented using a desk top personal computer and models the various components of a process loop including the final control, the process, and the measurement elements. Each element in the simulated process loop can be configured to model a first, second, or higher order system response. Also, each element in the process loop can be designed to incorporate dead times, disturbances, and noise to reflect conditions that are encountered in the field.