PID is a common algorithm for process control. It is used to keep a process variable, such as temperature, set at a certain set point by controlling an output variable. PID is made up of three parts, proportion (P), integral (I), and derivative (D). There are many good books on PID and recommend reading them for more information on PID control. This chapter describes PID control within DAQFactory and assumes a basic understanding of the algorithm, at least its uses and the meaning and effect of the three terms.
Within DAQFactory you can create as many PID loops as your computer will handle. Each loop runs in a separate thread within DAQFactory. A thread is like a separate program running concurrently with other threads running within DAQFactory. You can stop and start loops as necessary, independent of each other. Each PID is a standalone object and so whether using one PID loop or many, the process is the same.
