Creating the Harness Layout Drawing in Altium Designer

Parent page: Harness Design

Once the harness design has been captured in the form of a wiring diagram, the physical representation of the design can be created as a harness layout drawing.

Creating a New Harness Layout Drawing Document

To create a harness layout drawing of the harness design, a new Harness Layout Drawing document (*.LdrDoc) should be added to the harness project. To do this, right-click the project entry in the Projects panel and then select Add New to Project » Harness Layout Drawing from the context menu (or use the File » New » Harness Layout Drawing command from the main menus).

Add a harness layout drawing document to the harness project from the Projects panel's right-click menu.

A new blank document will open. To proceed, save the new harness layout drawing document using the standard File » Save As command from the main menus.

Options of a layout drawing document can be configured in the Properties panel in its Document Options mode, which is active when no object is selected in the document's design space. The main settings are:

• In the General region of the panel's General tab – select the measurement units that apply to the layout drawing document and its graphic elements and set the grids to enable easier placement. Altium Designer offers three grid types: visible grid for navigation, snap grid for placement and snap distance for aiding the creation of connections.
• In the Page Options region of the panel's General tab – configure document sheet size and title block or select from available schematic templates (*.SchDot).

 
The Document Options mode of the Properties panel (the General and Parameters tabs)

To import the design data from the wiring diagram, select the Design » Import Wiring Diagram command from the main menus. The connectors will be inserted into the layout drawing sheet in the relative positions defined in the wiring diagram. Connection points associated with connectors will also be placed next to each connector on the layout drawing. Applied changes will be listed in the Messages panel.

An example of a harness layout drawing with the wiring diagram data imported.

Each connector is represented on the layout drawing with its symbol. Click a connector in the design space to present its options in the Properties panel.

Multiple 3D physical model views for a connector can be added. To add views, in the Physical Model region of the Harness Component mode of the Properties panel, select Physical Model then click Add View. After a view is added, use the drop-down arrow to view and edit the properties of each view.

Socket crimps can be assigned to a component. To do this, select a harness component in the design space and open the Properties panel. On the Crimps tab, select a pin, then click . In the Select Connector dialog that opens, browse to and select a component from your available libraries. Pins with assigned crimps are denoted by a  symbol in the design space. An example is shown in the image below.

The Associated Parts tab allows parts such as heatshrinks to be assigned to the selected connector.

Defining Physical Arrangement on a Harness Layout Drawing

To better illustrate the procedure for defining a physical arrangement in a harness design, let's continue with the following example Layout Drawing, obtained through the import of the corresponding completed Wiring Diagram (hover to see this). Refer back to Defining the Wiring Diagram for more information.

Taking an example Layout Drawing. Here, the initial imported layout is shown. Hover the mouse over the image to see the source Wiring Diagram.

1. All physical connections within the harness are defined as harness bundles, even if a bundle contains just a single wire. Each bundle must start and end at a connection point. At the initial import, each component has a connection point associated with all its pins. This can be checked (and changed, if needed) in the Assigned Objects region of the Properties panel when the connection point of interest is selected.

   
   The properties of a connection point are placed automatically when the harness design data is imported into the layout drawing. Note that the connection point is associated with the connector and all its pins.

2. Connection points can be configured as needed according to your design intent. For example, only pins 1-5 should be selected for the connection point associated with P3. Select CP_P3 and deselect pins 6 and 7 in the Pins drop-down of the P3 entry in the Assigned Objects region of the Properties panel.

   

   Multiple objects can be added to a connection point by clicking the Add button in the Connectors region of the Properties panel. The Add Assigned Objects dialog opens in which you can enable the desired objects for the connection point.

   

   If an object already assigned to another connection point is selected in the dialog, corresponding warnings and icons will be shown. To avoid assigning a splice to more than one connection point, a splice is automatically removed from a connection point if it is already assigned to another connection point.

3. Place a harness bundle (using the Place » Harness Bundle command from the main menus or the Harness Bundle command from the Active Bar), starting at CP_P1 and ending at CP_P2. After selecting the command, click a connector point (a red cross appears at the cursor when it’s over a pin connection point) to place the start point of the harness bundle, and then click another pin to place the endpoint of the harness bundle. Right-click to exit the command and confirm the placement of the harness bundle, or click the start point of another harness bundle.

   

   When placing a harness bundle, press Shift+Spacebar to cycle through placement modes. The mode specifies how corners are created when placing bundles and the angles at which wires can be placed.  While in the 90 Degree or 45 Degree mode (true orthogonal modes), press Spacebar to cycle between the Start and End sub-modes.

4. When the harness bundle is selected, its properties can be seen in the Properties panel. The contents of the bundle can be seen in the Bundle Objects list. Note that the bundle includes wires W6 and W7 because these are the only two wires that directly connect P1 and P2.

   

   • Using the Length field in the panel's General (Harness Bundle) region, you can define the length of the selected bundle that can then be displayed in the project's ActiveBOM document.
   • If required, change the thickness and color of a bundle through the Properties panel (from the Width field and associated color swatch in the Vertices region).

5. For the wires between pins 1-5 on P1 and P2 to be included in the bundle, the splices (that were placed in the Wiring Diagram) must be included in the Layout Drawing. Place a connection point (CP1) onto the bundle using the Place » Connection Point command from the main menus or the Connection Point command from the Active Bar.

   

   This splits the original harness bundle into two separate bundles.

6. Place a harness bundle between connection points CP1 and CP_P3. In the same way as placing a wire, the left mouse button can be clicked during placement to place a vertex.

   

   The angle of the two sections of the bundle can be changed by dragging the vertex.

7. Select CP1 and note that each splice (SPL1, SPL2, SPL3, SPL4 and SPL5) is assigned to it. When harness bundles are connected to a connection point, the currently unassigned splices will automatically be assigned to the connection point according to the wiring diagram.

   

8. Each harness bundle will automatically contain the correct wires. For example, select the harness bundle between CP_P1 and CP1 (the bundle attached to CP_P1/CP1) to see that it now contains W1-A, W2-A, W3-A, W4-A, W5-A, W6, and W7.

   

   When a harness bundle is selected, you can click an object in the Bundle Objects region of the Properties panel to highlight all bundles through which the selected object goes.

   

   • In the case of a sophisticated, branched physical structure of a bundle, you might need to change the assignment of a wire to another bundle. Use the drop-down in the Bundle Objects Assignment region of the Properties panel when the required bundle is selected in the design space to update the wire assignment for this bundle as needed.
   • When a connection point that splits a bundle on a layout drawing in two is removed, the two bundles are automatically merged into a single bundle object.

9. The symbol for a connection point can also be changed to improve its appearance. With the connection point selected, use the Style control in the Properties region of the Properties panel.

   

10. Individual wires can be represented in the Layout Drawing as bundles containing a single wire. To include W13 and W14 in this way, place two connection points (CP2 and CP3) and assign connector P3 to them using the Add Assigned Objects dialog (click the Add button in the Properties panel to access the dialog). Assign pins 6 and 7 to CP2 and CP3 respectively (as shown below for CP3).

    

11. Next, place two more connection points (CP4 and CP5). Assign the No Connect directives Nc1 and Nc2 to CP4 and CP5 respectively (as shown below for CP5).

    

12. Place one bundle between CP2 and CP4 and another between CP3 and CP5. The first bundle (CP2-CP4) will automatically contain W13 (as shown in the image below) and the second (CP3-CP5) will contain W14.

    

    The appearance of the “wires” (bundles containing single wires) and the connection points associated with the unconnected ends can be changed to better represent their real appearance.

    

13. Physical labels can be placed into the layout drawing using the Place » Layout Label command from the main menus or the Layout Label command from the Active Bar. Properties of a label (its Designator, Location, Text, Font, and Justification) can be configured using the Properties panel when the label is selected in the design space.

    
    Layout labels can be placed into the layout drawing

An example of a complete layout drawing is shown below.

An example of a completed harness wiring diagram

Cross Probing between Wiring Diagram and Layout Drawing

Cross-probing between the wiring diagram and layout drawing of a harness project is supported. The Cross Probe command can be accessed on the Tools menu and the right-click context menu in the design space.

Cross-probing can be performed:

• between components on the wiring diagram and layout drawing;
• from a wire on the wiring diagram to the bundles to which this wire is associated on the layout drawing;
• from a bundle on the layout drawing to the associated wires on the wiring diagram.

Example of cross-probing between the wiring diagram and the layout drawing. Shown here is cross-probing from a component on the wiring diagram to the associated component on the layout drawing. Hover the cursor over the image to see cross-probing from a bundle on the layout drawing to the associated wires on the wiring diagram.