Frequency response signal analyzer for linear and non-linear control loops and dynamic systems. Simulink model. Sine sweep based similar to dynamic signal analyzers for physical systems. User specifies: freq limits, freq decrement, averages, phase criteria for moving to next frequency, start time, input amplitude. Output variable, freq_resp, with freq(rad/sec), closed loop magn, closed loop phase, open loop magn, open loop phase, time at each frequency. Performs 1/(T^-1 - 1) to convert closed loop Transfer function to open loop.