The Proportional-Integral-Derivative controllers are universal control structures that are widely used in Automation systems. The implementation of these controllers can be in either analog domain or digital domain. For the digital implementation we need to approximate a continuous integration function for Integral control action and a continuous differential function for the derivative control action. In this paper a simple implementation of a digital PID controller for a smart system or toy control system is proposed. As the integral controller is needed to NULL the constant error called offset, we take the samples of error which are measured at a differential time of unity, then for such a constant error the integral function will become summation. Similarly for the differential function we are using first order difference equation. The proposed controller is simulated on Virtual Instrumentation Platform using LabVIEW software. The implementation results after the inclusion of controller in a closed loop are also discussed.
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