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Check signal line connections

Check ID: mathworks.jmaab.db_0032

Guideline: db_0032: Signal line connections


Checks if the Simulink® signals that are intersecting and overlapping adhere to recommended guidelines.

This check requires a Simulink Check™ license.

Check Parameterization

This check contains sub-checks that correspond to sub IDs specified in the MAB and JMAAB modeling guidelines. You can use the Model Advisor Configuration Editor to specify which sub IDs (one or multiple) to execute.

For reference, the MAB guideline sub ID(s) that are recommended for use by the NA-MAAB and JMAAB modeling standards organizations are:

  • NA-MAAB — a1/a2, b, c, e

  • JMAAB — a1/a2, b, c, d, e


Subchecks db_0032_a1, db_0032_b, db_0032_c, db_0032_d, and db_0032_e are selected by default.

The input parameter Signal crossing threshold (in %) allows you to set a condition to fail the check if the set threshold is met. Signal crossing threshold is a percentage of signal violations to the total number of signal lines in the model.


If the Signal crossing threshold (in %) is set to 50%, then the check will only fail when number of violations crosses 50% of total number of Signal lines in the block diagram.

If the Signal crossing threshold (in %) is set to 0%, any single Violation will cause the Check to fail whereas, for 100% threshold, all Signal Lines in the model must be violating the guideline for the Check to fail.

Results and Recommended Actions

Guideline Sub IDConditionRecommended Action
db_0032_a1: Check signal intersectionsSimulink signals intersect each other.Reposition signal lines so that they do not intersect each other.
db_0032_a2: Check if Line crossing style is set to "Line hop"Line crossing style preference is not set to "Line hop".Set Line crossing style preference to "Line hop".
db_0032_b: Check signal overlapsSimulink signals overlap each other.Reposition signal lines so that they do not overlap.
db_0032_c: Check if signals are intersecting blocksSimulink signals are drawn over a Simulink block.Do not draw the signals over any Simulink blocks.
db_0032_d: Check if signal lines are split into multiple sublinesSignal lines are split into more than two signal lines at a single branch point.Reposition signal lines to avoid splitting into more than two signal lines at a single branch point.
db_0032_e: Check if signals are drawn as slanting linesSignal lines are drawn as slanting lines in the diagram.Draw signals as vertical or horizontal lines.

Capabilities and Limitations

  • Considers signal hop preference.

  • Does not analyze block label overlaps.

  • Considers Simulink signals that split into more than two signals at a single branch.

  • Runs on library models.

  • Allows exclusions of subsystems.

  • 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.