Chapter 2 Linear System Representation
Xmath Control Design Module 2-4 ni.com
be used so long as a consistent choice of variable is used for both numerator
and denominator polynomials.
The transfer function in pole-zero-gain form from the preceding equation
can be similarly implemented using the polynomial( ) function to
specify the numerator and denominator by their roots.
Note The / operator also can be used to create systems in transfer function form, as an
alternative to using system( ).
H4 = 2*polynomial(0.5,"s")/polynomial([-2,-4],"s")
which displays as:
H4 (a transfer function) =
2(s - 0.5)
--------------
(s + 2)(s + 4)
initial integrator outputs
0
0
Input Names
-----------
Input 1
Output Names
------------
Output 1
System is continuous
In both of these cases you have created a continuous system. Systems
created in Xmath contain sample rate information as well as the numbers
representing system dynamics. However, unless a sample rate is explicitly
given as a keyword to system( ), it defaults to zero and the system is
continuous. For an illustration of how to create a discrete system, refer to
Example 2-2. The full discussion of the system( ) function in the
system( ) section contains a listing of all the keywords associated with
system( ).