The Root Locus command automatically linearizes the system and produces a plot of the locus of closed-loop poles for the transfer function while it’s under gain feedback. The built-in auto-range capability determines the appropriate dynamic range of interest for performing the gain sweep. The number of steps in the sweep determines the number of points in the root locus plot.
Before you can generate a root locus plot of the system, prepare the system for linearization.
1. Choose Analyze > Root Locus Options to define the point count resolution of the root locus gain (K) values to be investigated.
2. Choose Analyze > Root Locus to generate a root locus plot.
A root locus plot appears in the upper left corner of the screen graphing the root locus of the specified system.