User`s guide

2 LTI Models
2-54
absorbs the input delay in H1 int o thetransfer functiondenom inatorto produce
the third -ord e r tra nsf er function
Transfer function:
1
---------
z^3 – z^2
Sampling time: 1
Note that
H2.inputdelay
now returns 0 (z er o).
Retrieving Information About Delays
There are s e veral way s to retri ev e time delay information from a given LTI
model
sys:
• Use property display commands to inspect t he values of the ioDelayMatrix,
InputDelay,andOutputDelay pr operties. For example,
sys.iodelay
get(sys,'inputdelay')
• Use the helper function hasdelay to determine if sys has any delay at all.
The syntax is
hasdelay(sys)
which returns 1 (true) if sys has a ny dela y, and 0 (false) otherwise
• Usethefunction
totaldelay t o determ in e the totalde laybet we eneachinput
and each outp ut (cumulative contributio n of the
ioDelayMatrix,
InputDelay,andOutputDelay properties). Typehelp totaldelay or see the
Reference pages for details.
Conversion of Models with Delays to State Space
When you use ss to convert TF or ZPK models to state-space form, the delays
in the resulting state-space model are redistributed when it is possible to
reduce the overall number of I/O delays, input channel delays, and output