National Instruments 370753C-01 Building System Connections

Building System Connections

Large system models are frequently built by connecting smaller models

together. You can perform different types of linear system interconnections

using the Xmath functions discussed in this chapter.

MathScript allows operators (*,+, and so on) to be overloaded—given

different behaviors when used with different objects. A number of simple

types of connections have been implemented as overloaded operators on

systems, while more complex connections are available through

specialized functions.

Overloaded operators provide a quick way to perform different types of

basic connections between systems. Table 3-1 illustrates these operations

on a pair of systems Sys1 and Sys2 with outputs y1 and y2 and inputs u1

and u2, respectively.

Table 3-1. Summary of Interconnection Operators

Diagram Description

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 = y

1 + y2. In the unary

case, Sys = –Sys1 where y=–y

1. The inputs are tied

together where u=u

1=u

Sys1

Sys2

+yu

Sys1

Sys2

–yu