Using Simulink

The Graphical Merge Tool Window

The Graphical Merge Tool window contains a menu, a toolbar, and panes that display the differences between the two models being compared. The menu provides commands for navigating and merging differences between the two models and for selecting various display options. The toolbar contains buttons that allow you to select many of the navigation, merge, and display options with a single mouse click. To display a tooltip specifying the function of a button, move the mouse cursor over the button and leave it there briefly.

Differences Panes

The tool window contains three panes that display differences between the two models. The top left pane displays the contents (blocks, states, transitions, etc.) of the first model in an expandable tree graph. Simulink color codes the items in the tree to highlight differences between the first and second model (see How Simulink Highlights Model Differences).

The top right pane displays a similarly color-coded tree highlighting differences between the second and the first model. Clicking an item (block, state, transition) in either pane highlights the corresponding block icons in the model views.

The items in the two content panes are aligned so as to accentuate differences between the two models. An item that appears in both models appears at the same relative position in the content pane for each model. If an item appears in only one of the two models, the corresponding position in the other model's content pane is empty. This visual alignment of the content panels makes it easy to spot differences between the two models.

The bottom pane displays differences between parameters of the selected block if the block exists in both models. If you are not interested in parameter differences and need more space for viewing graphical differences, you can eliminate this pane by clearing Show parameter differences on the Graphical Merge Tool's View menu.

You can adjust the relative sizes of the panes by dragging the dividers between them.

Model History List

At the top of each content pane is a drop-down list of the four models that have most recently appeared in the pane. To compare any model on the list to the model in the other pane, select the model and press Return.

How Simulink Highlights Model Differences

The Graphical Merge Tool uses the following color code to highlight differences between two models.

Color	Indicates
Red	Items that appear in both models but with different parameter values or content (in the case of subsystems).
Black	Container items (for example, subsystems or super states) that contain items that differ but otherwise are the same in both models.
Blue	Items that appear in one model but not in the other.
Gray	Items that appear in both models and have identical content and parameters in both models.

Model Differences Flagged by the Graphical Merge Tool

The Graphical Merge Tool flags the following types of differences between models:

• Item name differences

• The Graphical Merge Tool considers items that differ only in name to be different. For example, suppose that a subsystem appears at the same place in model A and in model B and that both subsystems have identical content but different names. The tool flags each subsystem as unique.

• Block parameter differences

• Two otherwise identical blocks are considered different if any of their saved parameters are different. For example, suppose that a Gain block appears at the same place with the same name in models A and B, but that gain in the first instance is 1, and in the second instance is 2. The tool flags the two instances as different.

• Block connection differences

• A connection between a block output and a block input is considered unique to one model if the same connection does not occur in the other model. (The Graphical Merge Tool does not compare unconnected lines.)

Differences Display Options

The Graphical Merge Tool's Options menu allows you to control the level of detail displayed by the differences panes. For example, you can show all items in the models being compared or only items that have nongraphical differences. The display options include

• Show all items

• Show all blocks in the model. If the model contains Stateflow charts, this option displays all the states, transitions, subcharts, and graphical functions contained by the charts.

• Show items with differences only

• Display only items that differ between the two models.

• Show all differences

• Display all blocks that differ in any way between the models.

• Show only nongraphical differences

• Display only blocks that differ nongraphically between the two models. For example, this option does not display blocks that differ only in position, size, orientation, or color.

Graphical Merge Tool

Navigating Model Differences