Logical dependency analysis

The functional dependencies visualized in the previous sections related to the (physical) exchange and transformations of flows between components of the system.

From a (supervisory) control perspective however one is more interested in the dependencies that relate to the behavior of components. For example, the relation between the output of a sensor and the output of an actuators. Such dependencies are often embedded within the (control) software of a system. The ESL compiler can derive such dependencies from ESL behavior specifications.

Figure 1 shows an MDM listing the components, function specifications, and behavior specifications relevant at the second decomposition level of the final specification. Within the matrix, logical dependencies and mapping dependencies are shown. For example, power-source has a logical dependency with power-switch. This dependency is derived from behavior-requirement toggle-power that logically relates the value of motor-control-signal, sent by power-switch, to the value of power, produced by power-source.

Figure 1: Component-function-behavior spec multi-domain matrix showing logical dependencies at the second decomposition level.

Similarly, function specifications send-control-signal and convert-potential have a logical dependency as the output of convert-potential is defined by the value of motor-control-signal.

The bottom row of Figure 1 shows which components and function specifications are affected by behavior specification toggle-power.

Note

The function specifications send-control-signal and convert-potential in Figure 2 of Functional Dependencies do not have a functional dependency as motor-control-signal is not (physically) converted into power.