Specifications

13 SISO Design Tool Reference
13-14
•Loop transfer — This is defined as the compensator (C), the plant (G), and
the sensor (
H) multiplied together (CGH). If you haven’tdefinedasensor,its
default value is 1.
•Sensitivity function — This is defined as , where L is the loop transfer
function.
Some of the open- and closed-loop responses use these definitions. See
“Contents of plots” for more information.
Plots. You can have up to six plots in one LTI Viewer. By default, the Response
Plot Setup window specifies one step response plot. To reconfigure the LTI
Viewer for more plots, start by selecting “2. None” from the list of plots and
thenspecifyanewplottypein the
Changeto field. Plot types available include
the following:
•Step
•Impulse
•Bode
•Bode Magnitude
•Nyquist
•Nichols
•Sigma
•Pzmap (pole/zero map)
•None (deselect a plot)
Note that you do not have to select adjacent numbers; for example, if you
specifyplot#1tobeastepresponse,plot#2tobenone,andplot#3tobean
impulse response, the LTI Viewer will open with two plots, a step and an
impulse response. There will not be an empty plot region.
Contents of plots. Once you have selected a plot, you can specify various open-
andclosed-looptransfer functions.Youcan plot open-loop responses foreachof
the components of your system, including your compensator (
C), plant (G),
prefilter (
F), or sensor (H). In addition, loop transfer and sensitivity transfer
functions are available. Their definitions are listed in the Response Plot Setup
window.
See the block diagram in Figure 13-7, Response Plot Setup Window for
definitions of the input/output points for closed-loop responses.
1
1 L+
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