National Instruments 370753C-01

Chapter 3 Building System Connections

Xmath Control Design Module 3-2 ni.com

Sys = Sys2 * Sys1 Cascade connection of Sys1 and Sys2 where the output

of Sys is y2 and the input is u1.

Sys = Sys1/Sys2 Cascade connection of Sys1 and inverted Sys2 where

Sys = Sys1* inv(Sys2), u=u

2, and y = y1.

Sys = Sys1\Sys2 Cascade connection of inverted Sys1 and Sys2 where

Sys = inv(Sys1) * Sys2, u = u2, and y = y1.

Sys = [Sys1;Sys2 Parallel connection where y = [y1;y2]. The inputs are

tied together where u=u

1=u.

Sys = [Sys1,Sys2 Parallel connection where y = y1 + y2 and

u =[u1;u2].

Sys = Sys1' If Sys1 is in state-space form and comprises the matrices

(A1,B1,C1,D1), Sys comprises (A1',C1',B1',D1').

If Sys1 is a transfer function, it is converted internally

to state-space form.

Table 3-1. Summary of Interconnection Operators (Continued)

Diagram Description

Sys1 Sys2 y

uu1 u2y1 y2

inv(Sys2) Sys1 y

uu2 u1y2 y1

Sys2 inv(Sys1) y

uu2 u1y2 y1

Sys1

Sys2

Sys1

Sys2