MATLAB: Do I receive an error when using the Demux block with Exported Global outputs in Simulink

simulink

I have a model 'test_error.mdl' with a Demux and the storage class setting of the outputs are 'Exported Global'. When I try to run the model, I receive the following error:

 The signal attribute {StorageClass = 'ExportedGlobal'} specified on the line originating from the output port 1 of 'test_error/Demux' is invalid because the individual signals contained in this line are mapped to different memory locations. The StorageClass for this line must be set to 'Auto'.

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The error message you observe is due to expected behavior. In order to specify a storage class other than "Auto" on the outputs of the Demux block, each of the outputs must have unique memory locations. Whereas, by default, the outputs of the demux block are elements of one contiguous block of memory. The attached workarounds allow the use of the 'ExportedGlobal' class by forcing the outputs of the Demux block to be stored in separate non-contiguous memory locations.

Workaround 1. You can use the 'Signal Conversion' block as shown in 'test_workaround.mdl'.

Workaround 2. Change the storage class of the input signal of the Demux block to 'Exported Global' i.e. to have a single memory location as shown in 'test_workaround2.mdl'.

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MATLAB: Do I receive an error when I connect a Bus Selector block to the output of a Signal Conversion Block in Simulink 6.1 (R14SP1)

This bug has been fixed in Release 14 Service Pack 3 (R14SP3). For previous product releases, read below for any possible workarounds:

This is the expected behavior of a bus signal. If a bus enters a Signal Conversion block whose mode is set to contiguous copy, the signal leaving the block should be treated as a vector. Specifically, a Bus Selector block should not be placed on the signal leaving the block. Even if a Bus Selector is connected to the signal leaving the Signal Conversion block, the signals in the bus will be visible in the Bus Selector dialog box. Therefore, although it may appear that it is valid to use the Bus Selector on that signal, this practice is not permitted.

MATLAB: How to modify the signal properties from a Simulink model in Simulink 6.2 (R14SP2) from the command line

You can modify the signal properties by using the SET_PARAM function. For example:

Download the attached model and open it.

 test.mdl

The signal from the Inport is named as 'The_Signal'. The "RTW storage class" for this signal can be set by executing the following code at the MATLAB command prompt:

theports=get_param('test/In1','porthandles'); %Get the port handles
outport = theports.Outport;

By default, the "RTW Storage class" is set to "Auto". To change the class to "ExportedGlobal" type the following at MATLAB command prompt.

set_param(outport,'RTWStorageClass','ExportedGlobal');

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MATLAB: Do I receive an error when I connect a Bus Selector block to the output of a Signal Conversion Block in Simulink 6.1 (R14SP1)

MATLAB: How to modify the signal properties from a Simulink model in Simulink 6.2 (R14SP2) from the command line

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