The objective of the laboratory exercise is to study the characteristics of linear dynamic systems. In control engineering, in order to analyze and design control systems, a mathematical model of the actual plant is required. This model approximates the behavior of the plant to some extent. By engineering necessity, a number of assumptions have to be made about the plant in order to obtain the model. The nature and validity of the assumptions must be borne in mind when applying control theory to real engineering systems. Analysis and design taking into account the amount of difference between the actual plant and model is a more advanced topic. One of the most common assumptions is that the plant is linear. This is valid for most plants within a certain limited operating range. The second assumption is that the plant dynamics are exactly known and are time invariant. Again, this is valid to some extent, but the fact that the plant dynamics and system disturbances are not exactly known, and their characteristics change over time is what motivates the use of feedback. Indeed, if the plant and disturbances were exactly known, there would be no need for feedback control, all control could be open-loop. However, for the sake of designing the feedback controller, this assumption is made. Another common assumption is that the plant is second order. This assumption can be made for a great many simple control systems (such as servo systems). This is because the higher order dynamics are generally of high frequency, and are thus beyond the bandwidth of the system. In the first part of the exercise, step response method can be applied to the actuator input and observing the response in which actual (stable) plants can be identified and modelled. In the second part of the exercise, some additional characteristics of second and third order systems are investigated by studying the effects of adding real poles and zeros to a second order system. In the third part of the exercise, frequency response method by means of applying sine waves over a range of frequencies and observing the gain and phase change of the output is investigated.