# Remove Cross-Hierarchy Signal Backward

This action removes a (bus) signal backward across the subsystem hierarchy. It removes all lines, Goto and From blocks, subsystem inports/outports, bus selector outports, and bus creator inports inbetween and stops at a chosen stopping block. Only those stopping blocks can be selected in the action's dialog up to which a removal is safe, so that other signal branches do not lose their source signal. If a bus line is selected, the action opens another dialog where you can choose the bus signal to remove.

Example 1:

Remove the selected non-bus signal from the rightmost subsystem backward across multiple subsystem boundaries. The stopping block is the third inport of the leftmost subsystem with path Before/c.

Example 2:

Remove selected bus signal from the right subsystem backward across the subsystem hierarchy. The bus signal x is chosen for removal. Stopping block is the third inport of the left subsystem with path Example 2/After/In3.

Example 3:

The sub-signal B was selected for removal. This sub-signal is also used in another signal branch that is not selected here. Therefore, in the Choose Stopping Block dialog, to prevent the other signal branch from losing its source signals, you can only select those stopping blocks up to which a removal is safe. The upper text field in the dialog provides more information about why some blocks are grayed out and why you cannot select them.

Usage:

Select the line where you want to start the backward removal. Then select the action. If you selected a bus line, a dialog will appear where you can specify the bus signal to be removed. If you want to remove the complete bus, select the top node. Click Ok to continue. From the Choose Stopping Block dialog that appears, choose the block where you want to stop the removal. You can double-click the block paths in the dialog to show the block in the Simulink® editor. After choosing the stopping block, click Ok to start the action.