Known Software and Documentation Problems

This document describes important known software and documentation problems:

Simulink

Click on a problem area listed below for details.

Backwards Compatibility of Tunable Parameters for Unified Fixed-Point Blocks
Help ->Blocksets Submenu Sometimes Fails To Appear
S-Function Builder Causes MATLAB to Hang If mex Is Not Set Up Correctly
Simulink Scope will not update time offset when "Tick Labels" are set to "Bottom Axis Only"
Zero sample time limitation on discretizing models in the S domain

Backwards Compatibility of Tunable Parameters for Unified Fixed Point Blocks

Fixed Point Blocks with tunable parameters have compatibility problems under certain conditions when loaded as Unified Blocks in Release 13. The problem arises only if the tunable parameter is mapped to a builtin integer data type or to single. There are no compatibility problems if the parameter maps to non-builtin data type such as a scaled fixed point integer.

When tunable parameters are mapped to builtin integers (or single), two types of problems may arise. One problem is that code generated by Real Time Workshop in Release 13 may be less efficient than was generated in earlier releases. The problem arises because Simulink and Fixed-Point Blockset have different rules for mapping the data types of dialog parameters to the data type used in online computations. Simulink's rule requires the data type used in the dialog be preserved in the generated code. Fixed- Point Blockset's rule treats the dialog parameter as providing only an ideal real world value; no data type information is sought from the dialog parameter even if it is tunable. I need to put more here but have not finished. Andy B Thur Sept 12, 10:24

Help ->Blocksets Submenu Sometimes Fails to Appear

The Blocksets submenu sometimes fails to appear when selected from the model window's Help menu. If this happens, click anywhere in the model window and then select "Blocksets" from the Help menu.

Insure Data

S-Function Builder Causes MATLAB to Hang If mex Is Not Set Up Correctly

The S-function Builder block causes MATLAB to hang if the compiler options file is not setup correctly. To avoid this problem type the following at MATLAB command prompt to configure the compiler options file:

mex -setup

Simulink Scope will not update time offset when "Tick Labels" are set to "Bottom Axis Only"

The Simulink Scope has three modes for its "Tick Labels," which can be set in the scope parameters dialog box. The three settings are "all," "none", and "Bottom Axis Only" (the default). Using the third (default) setting triggers a bug in which the "Time Offset" in the bottom, left corner of the scope does not update properly. To work around this setting, set the "Tick Labels" to "all".

Zero sample time limitation on discretizing models in the S domain

When discretizing a model in the S domain, you cannot specify a sample time of 0 if the model contains a Transfer Function, State Space, or Zero Pole block. If you do specify a sample time of 0, MATLAB generates an error.