When the Main Ring schematic layout algorithm is chosen in the Layout Task drop-down list, clicking the 
on the Schematic Editor toolbar opens its associated properties dialog box as follows:
The parameter values are those either specified by default by Schematics or specifically set as the default for the schematic diagram template related to the active diagram using the Schematic Dataset Editor Layouts tab for this schematic diagram template.
Ring Type options
The Ring Type options specify the form of the main ring.
- Choose the Ellipse option to lay out the schematic nodes of the detected main ring around an ellipse. This is the default option unless another default option is specified for the diagram template related to the active diagram.
- Choose the Rectangle option to have the main ring nodes form a rectangle.
The figures below show the Main Ring type parameters. Figure 1.1 represents the initial schematic diagram. Figure 1.2 shows the result when the Ellipse ring type option is selected. Figure 1.3 shows the result when the Rectangle ring type option is selected.
Ring Dimension parameters
The Ring Dimension parameters define the dimension of the ring. The unit for these parameters depends on the Absolute units check box.
- The Width parameter determines the width of the ring. By default, the Width value is set at 50 unless another default width value is specified for the diagram template related to the active diagram.
- The Height parameter determines the height of the ring. By default, the Height value is set at 20 unless another default height value is specified for the diagram template related to the active diagram.
The figures below show how the ring is displayed according to different values of the Width and Height parameters while the Absolute units check box is unchecked.
Trees Type options
The Trees Type options determine the layout of the trees coming out of the main ring's nodes.
- Choose the Both sides of main line option if you want each tree to be displayed hierarchically along a main line and its related branches to be displayed on both the left and right sides of this main line. This is the default option unless another default option is specified for the diagram template related to the active diagram.
- Choose the Left side of main line option if you want each tree to be displayed hierarchically along a main line and its related branches to be displayed only on the left side of the main line.
- Choose the Right side of main line option if you want each tree to be displayed hierarchically along a main line and its related branches to be displayed only on the right side of the main line.
- Choose the Compact tree option if you want each tree to be displayed hierarchically as a compact tree.
- Choose the Smart tree option if you want each tree to be displayed hierarchically as a smart tree.
Figures 3.1–3.6 below show the Main Ring layout results for each of the available Type options.
Spacing parameters
The Spacing parameters determine how the spacing between the trees' hierarchical levels and the schematic nodes belonging to a given tree's hierarchical level is computed. The unit for these parameters depends on the Absolute units check box.
- The Between nodes along the direction parameter determines the spacing between schematic nodes that are displayed along the tree direction.
- The Between nodes perpendicular to the direction parameter determines the spacing between schematic nodes that are displayed perpendicularly to the tree direction and that belong to the same subtree level.
The figures below show the Main Ring result with different values for the Between nodes perpendicular to the direction and the Between nodes along the direction parameters when using the Compact tree type to arrange the tree coming out of the main ring's nodes and the Absolute units check box is unchecked. Figure 4.1 represents the initial schematic diagram. Figure 4.2 shows the result when Between nodes along the direction = 5 and Between nodes perpendicular to the direction = 5. Figure 4.3 shows the result when Between nodes along the direction = 10 and Between nodes perpendicular to the direction = 5. Figure 4.4 shows the result when Between nodes along the direction = 15 and Between nodes perpendicular to the direction = 10.
Link display parameter
Type a number between 0 and 1 to define the relative position of the break point on the last segment of the tree schematic links. The default value is 0.5 unless another default number is specified for the diagram template related to the active diagram.
When Break point is set to a value of 0, this segment length is the longest, and it is displayed with a right angle. With a break point value of 1, this segment doesn't exist, so each link directly connects its two extremity nodes without an intermediate point.
Figures 5.1–5.6 below show the Main Ring layout results with different break point values.
Links currently selected prevent the algorithm from executing beyond them check box
All Schematics layout algorithms apply on all features in the diagram or on the currently selected features in the diagram.
The Main Ring layout algorithm works in the same way except when the Links currently selected prevent the algorithm from executing beyond them check box is checked. When this box is checked, the currently selected links are interpreted as barriers beyond which the algorithm is not applied.
By default, this check box is unchecked.
Absolute units check box
By default, the Dimension and Spacing parameters are interpreted as absolute units determined by the coordinate system specified on the XY Coordinate System tab of the Schematic Diagram Properties dialog box (Absolute units checked). Uncheck the Absolute units check box if you want these parameter values to be interpreted as units relative to the average of the current symbol sizes used to represent the schematic nodes in the diagram. In this case, when the Width parameter value is 6, the main ring width corresponds to the average size of six symbols placed side by side.
Restore Defaults button
Click the Restore Defaults button to set all the Main Ring parameters to their default values. The restored values are those either specified by default by Schematics or specifically set as the default for the schematic diagram template related to the active diagram using the Schematic Dataset Editor Layouts tab for this schematic diagram template.