Discrete Process Control Systems

 Sequencing is one of the types of discrete process control. This type of discrete process control uses internal timing devices to determine when to initiate changes in output variables. Many sequencing applications require the controller to provide a pre-scheduled set of ON/OFF values for the output variables. Discuss an example of a discrete process control system with sequencing. Identify the input and output process variables and examine the process in detail. 

 Parameters and variables that change values at discrete moments in time fall under the scope of discrete process control systems. These parameters and variables are typically binary and are represented by a 0 or 1. The input signals may be generated by process limit switches or photo-sensors, while output signals turn on and off switches, motors, valves, and other binary actuators related to the process.