Performance evaluation of a programmable controller

The author proposes a queuing model which is effective in predicting the performance capacities (saturation points) of sequential control systems using service algorithms. In this model, the performance capacity is measured by the average number of service requests in each queue. This model uses the characteristics of a service algorithm of a programmable controller with the assumption that the service requests follow a Poisson process. Numerical examples indicate that the expected performance capacity depends on the service algorithm. It is shown that significant increases in the performance of sequential control applications are brought about by the service algorithm