Main Content

jc_0171: Clarification of connections between structural subsystems

Guideline Publication

Control Algorithm Modeling Guidelines - Using MATLAB®, Simulink®, and Stateflow®

Sub ID Recommendations

  • NA-MAAB — No recommendations

  • JMAAB — a, b

MATLAB Versions

All

Rule

Sub ID a

Visual depiction of signal flow shall be clearly shown between subsystems.

Use of Goto and From blocks shall be allowed if:

  • At least one signal line is used between connected subsystems.

  • Subsystems connected in a feedback loop have at least one signal for each direction.

Exception

Using Goto and From blocks to create buses or connect inputs to Merge blocks.

Custom Parameter

Not Applicable

Example — Correct

Example — Incorrect

Sub ID b

Structural subsystems shall not have pass through signals exclusively for signal routing.

Custom Parameter

Not Applicable

Example — Correct

Example — Incorrect

Signals that are not used in the subsystem are connected to avoid crossing of signal lines.

Rationale

Sub ID a:

  • Clarifies structural subsystem connections and execution order.

Sub ID b:

  • Eliminating unnecessary connections clarifies the relationship between connections.

  • Deviation from the rule can cause to confusion due to unused input/output signals.

Verification

Model Advisor check: Check connections between structural subsystems (Simulink Check)

Last Changed

R2025a

Version History

Introduced in R2020a