Digital systems
Static systems

Some systems do not apparently exhibit any intrinsic dynamics, we call them static systems or systems without dynamics. For example, an amplifier or transducer. In closer view, we can see, that these systems do have dynamics as well, and value changes contain transient responses. These transients, however, can be inappreciable to us (e.g. lighting a bulb, switching a contact or thermostat, dial pointer displacement, electric or pneumatic motor run or stop).

Sometimes the transient is apparent, but for particular purpose its dynamics is not significant, and it can be neglected. For example, the process of opening or closing of heater valve or settling of thermometer value is not significant in temperature control, which is a substantially slower process. For a logical control of manipulator, we are concerned in a trajectory, velocity and end points of motion, but the acceleration and deceleration dynamics lies outside of our interest. Similarly, in programming of numerically controlled machining, we are concerned in a trajectory and velocity along the path and we hope that servo motors of slide rests perform well enough. On the other hand, there is a technician, who has to tune up the dynamics of servo motors. As elevator passengers, we feel clearly the system dynamics, but as logical controller programmers, we do not take it into account – we let it up to elevator constructors and servicemen.