User`s guide

1 Overview of S-Functions
1-12
S-functions can be either single or multirate; a multirate S-function has
multiple sample times.
Sample times are specified in pairs in this format: [
sample_time,
offset_time
]. The valid sample time pairs are
[CONTINUOUS_SAMPLE_TIME, 0.0]
[CONTINUOUS_SAMPLE_TIME, FIXED_IN_MINOR_STEP_OFFSET]
[discrete_sample_time_period, offset]
[VARIABLE_SAMPLE_TIME, 0.0]
where
CONTINUOUS_SAMPLE_TIME = 0.0
FIXED_IN_MINOR_STEP_OFFSET = 1.0
VARIABLE_SAMPLE_TIME = -2.0
and the italics indicate a real v alue i s required .
Alternatively, y ou can specify that the sample time is inherit ed from the
driving b lock. In this case the S-function can have only one sample time pa ir
[INHERITED_SAMPLE_TIME, 0.0]
or
[INHERITED_SAMPLE_TIME, FIXED_IN_MINOR_STEP_OFFSET]
where
INHERITED_SAMPLE_TIME = -1.0
The following guidelines may help you specify sample times:
• A continuous S-function that changes during minor integration steps should
register the [
CONTINUOUS_SAMPLE_TIME, 0.0]sampletime.
•Acontinuous S-function thatdoesnot changeduring minor integrationsteps
should register the
[CONTINUOUS_SAMPLE_TIME, FIXED_IN_MINOR_STEP_OFFSET] sample time.