Select the diagnostic action to take if Simulink® software could not infer the data type of a signal during data type propagation.
Category: Diagnostics
This example shows how to use the configuration parameter Underspecified data types to identify and resolve an underspecified data type.
Open the example model ex_underspecified_data_types.
Set the Underspecified data types configuration parameter to
warning.
Update the diagram.
The signals in the model use the data type uint8,
and the model generates a warning.
Open the Diagnostic Viewer. The warning indicates that the output signal of the Constant block has an underspecified data type.
Open the Constant block dialog box.
On the Signal Attributes tab, Output
data type is set to Inherit: Inherit via back
propagation. The Constant block output
inherits a data type from the destination block. In this case, the
destination is the Sum block.
Open the Sum block dialog box.
On the Signal Attributes tab, Accumulator
data type is set to Inherit: Inherit via internal
rule. Sum blocks cast all of their input
signals to the selected accumulator data type. In this case, the accumulator
data type is specified as an inherited type.
Open the Inport block dialog box. On
the Signal Attributes tab, Data type is
set to uint8.
The data type of the Constant block output signal is underspecified because the source and destination blocks each apply an inherited data type. The signal cannot identify an explicit data type to inherit. In cases like this, Simulink applies heuristic rules to select a data type to use.
To resolve the underspecified data type, you can use one of these techniques:
On the Signal Attributes tab
of the Constant block dialog box, specify Output
data type as a particular numeric type, such as uint8.
On the Signal Attributes tab of the Sum block dialog box, select the check box Require all inputs to have the same data type.
With this setting, the Sum block applies the
data type of the first input, uint8, to the underspecified
data type of the second input.
Default: none
noneSimulink software takes no action.
warningSimulink software displays a warning.
errorSimulink software terminates the simulation and displays an error message.
Parameter: UnderSpecifiedDataTypeMsg |
Value: 'none' | 'warning' | 'error' |
Default: 'none' |
| Application | Setting |
|---|---|
| Debugging | No impact |
| Traceability | No impact |
| Efficiency | No impact |
| Safety precaution | error |