Check signal line labels
Check ID:
        mathworks.maab.na_0008
Guideline: na_0008: Display of labels on signals
Description
Check the labeling on signal lines.
Use a label to identify:
- Signals originating from the following blocks (the block icon exception noted below applies to all blocks listed, except Inport, Bus Selector, Demux, and Selector): - Bus Selector block (tool forces labeling) 
- Chart block (Stateflow®) 
- Constant block 
- Data Store Read block 
- Demux block 
- From block 
- Inport block 
- Selector block 
- Subsystem block 
 - Block Icon Exception - For Constant and Data Store Read blocks, if a signal label is visible in the display of the originating block, you do not have to display a label for the connected signal unless the signal label is required elsewhere due to a rule for signal destinations. 
- For Subsystem, Chart, and From blocks, if a signal label is visible in the display of the originating block, and signal Propagation for the signal is enabled by signal property - Show propagated signals, you do not have to display a label for the connected signal.
 
- Signals connected to one of the following destination blocks (directly or indirectly with a basic block that performs an operation that is not transformative): - Bus Selector block (tool forces labeling) 
- Chart block (Stateflow) 
- Data Store Write block 
- Goto block 
- Mux block 
- Outport block 
- Subsystem block 
 
- Any signal of interest. 
This check requires a Simulink® Check™ license.
Check Parameterization
To customize the blocks and masks for this check, use the Model Advisor Configuration Editor.
- Open the Model Configuration Editor and search for check ID - na_0008.
- Under Input Parameters, select - Customfrom the Standards list.
- Add or delete the blocks and/or masks from the List of block types to check output signal labels and List of block types to check input signal labels tables. 
- Click Apply and save the configuration. 
Results and Recommended Actions
| Condition | Recommended Action | 
|---|---|
| Signals coming from Bus Selector, Chart, Constant, Data Store Read, Demux, From, Inport, or Selector blocks are not labeled. | Label the signal. | 
| Blocks from the list below that receive signals are not labeled: Outport, Goto, DataStore, BusCreator, Mux, or SubSystem. | Label the signal. | 
Capabilities and Limitations
- Runs on library models. 
- Allows exclusions of blocks or charts. 
- Analyzes content of library-linked blocks. By default, the input parameter Follow links is set to - on.
- Analyzes content in masked subsystems. By default, the input parameter Look under masks is set to - graphical.