Chapter 3 Building System Connections
Xmath Control Design Module 3-8 ni.com
append( ) performs a check to make sure both Sys1 and Sys2 have the
same sample rate, and adopts this rate for the appended system. Any initial
conditions on the states are also appended columnwise.
connect( )Sys = connect(Sys1,{K,M,N})
The connect( ) function performs a general interconnection around a
system. This provides two basic capabilities:
• constant gain feedback
• general input–output interconnection
In its simplest form, connect( ) can be used to wrap constant gain
feedback around a system. The keyword K, used to specify feedback gain,
also can be used to specify which outputs are fed back to the input of the
system. By specifying the optional keywords M and N, you also can specify
input and output gains.
General input–output interconnection is applicable to the block form
system provided by append( ), as described in the append( ) section.
Parameters used in the connect command are illustrated in Figure 3-3.
Notice that feedback is defined with a positive sign.
Figure 3-3. Parameters Used with the connect Command
AA10
0A2
=BB10
0B2
=
CC10
0C2
=DD10
0D2
=
u
1
u
k
uyy
1
Sys
1
N
Sys
M++
K