Sundance SMT9650 - Manual (Page 6)

Document No.
S M T 9 6 5 0 U s e r G u i d e
Revision
3 . 0
Date
2 9 D e c 2 0 0 6
Page
6 of 36
4 CONSTRAINTS
Labview and Simulink have different models of computation, and two constraints are necessary in order
to allow them to cooperate.
1.1 SIZE CONSTRAINT
The size of arrays handled by Labview VIs is determined by the source of the data; for the input
instruments this will be Simulink (from the DSPs) and for the output instrument it will be Labview. When
running a system entirely within either the Simulink or Labview environments, matching of data sizes is
mostly done for you. In the hybrid environment of the SMT9650, you must make sure that array sizes
match the requirements of the data destination manually.
1.2 ORDERING CONSTRAINT
The code generated by Simulink imposes a strict ordering constraint on the application; all input sources
will be read before all output sinks are written. This means that the loop in Labview communicating with
the DSP system must ensure that all the SMT9650 output VIs are executed before all of the input VIs. The
simplest way to achieve this is to use a flat sequence and make sure that all your output VIs appear in one
frame and all the input VIs appear in the next.