Synchronizing a Harness Design Project

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Accessing the ECAD-MCAD Harness Sync Capabilities

  • Refer to the Note in the right-hand pane for information on whether Harness Synchronization will be available in your installation of MCAD CoDesigner.

  • Harness synchronization is currently available for PTC Creo (MCAD CoDesigner 3.5 and later) and SOLIDWORKS (MCAD CoDesigner 3.6 and later), support for other MCADs will be added in future updates.

  • In SOLIDWORKS, you need SOLIDWORKS Routing Electrical (included in the SOLIDWORKS Premium package) to be able to synchronize the harness. Please note that SOLIDWORKS Routing Electrical requires Microsoft Excel to be installed to be able to read the harness connectivity information.

Many electronic devices are built as an assembly of multiple circuit boards, cleverly shaped and arranged within a mechanical enclosure to deliver an aesthetic and useful product. Altium's electronic design (ECAD) software supports this, where multiple PCBs can be brought together to create an assembly of PCBs, called a Multi-Board Assembly. This assembly can also include the enclosure, other mechanical elements that make up the product, and the wiring harness that connects the PCBs within the enclosure.

MCAD CoDesigner supports synchronizing Harness Projects between Altium Designer and SOLIDWORKS, and Altium Designer and PTC Creo. This page outlines the support for synchronizing Harness Projects, to learn more about synchronizing Multi-board assemblies, refer to the Synchronizing a Multi-board Assembly page.

  • From ECAD, CoDesigner sends the following information about the Harness to MCAD:

    • Connectors,

    • Splices,

    • Connectivity ("from-to" data), and

    • Harness Topology (connection points with the sets of wires and cables going through those points).

  • From MCAD, CoDesigner sends the results of 3D Harness routing back to the ECAD Harness Layout Drawing, including:

    • The physical length of wires, cables, and harness segments.

    • The 3D model of the Harness can also be sent to ECAD during Multiboard Assembly synchronization, along with the mechanical enclosure parts.

CoDesigner does not build the Harness Topology in ECAD's Layout Drawing after synchronizing back from MCAD, so the Harness Topology should be specified in that document before back synchronization. Learn more about Harness Design in Altium Designer.

MCAD CoDesigner Harness Capabilities Copy Link Copied

MCAD CoDesigner’s harness support integrates the ECAD and MCAD models of the harness. The ultimate goal is to allow the harness geometry to be designed in MCAD and then transferred back to ECAD, as the physical parameters (lengths) of the harness elements.

The initial harness schematic/wiring diagram is captured in ECAD, as a Harness Wiring Diagram (*.WirDoc). The logical connectivity is then transferred to a Harness Layout Drawing (*.LdrDoc), where the physical implementation details of the harness, such as the wire and cable details, crimps, connectors, and so on, are defined.

The ECAD Harness Layout Drawing editor does not support defining the 3-dimensional geometry of the harness, this is done in MCAD, using Altium MCAD CoDesigner to synchronize the harness design to your preferred MCAD editor. Once the exact 3-dimensional properties of the harness have been designed in MCAD, Altium MCAD CoDesigner can synchronize that detail back to ECAD, ready for completion of the design documentation, including assembly drawings and the Bill of Materials.

This section, MCAD CoDesigner Harness Capabilities, outlines how the connective detail and the physical elements in the harness are transferred between ECAD and MCAD. After that, the MCAD CoDesigner Harness Workflow section outlines the process of transferring the design back and forth between ECAD and MCAD.

Advanced User Documentation & Troubleshooting Tips

For a more detailed explanation of how MCAD CoDesigner supports ECAD-MCAD harness synchronization, refer to the Understanding Harness Synchronization – Advanced Users page.

Transferring the Connectivity Information

  • CoDesigner transfers the connectivity information (standard From-To information) from ECAD to MCAD.

  • In PTC Creo, CoDesigner creates the corresponding Spool entities for each wire/cable according to the connectivity info. Note that these Spools are not reused, this is planned to be implemented in a future update.

  • In SOLIDWORKS, CoDesigner creates the corresponding entities (records) in the Routing Library for each wire/cable, according to the connectivity information. These entities are not reused, this is planned to be implemented in a future update.

Wire/Cable Properties

 
 
 
 
 

MCAD CoDesigner versions 3.9 and lower:

  • CoDesigner uses the following ECAD parameters to configure the corresponding wire/cable properties in MCAD:

    • Thickness / THICKNESS
      When specifying values in ECAD the units must not be included, they are defined in the Units parameter. If the Thickness is not defined in ECAD, MCAD CoDesigner sets the THICKNESS of wires to 1 mm and cables to 3 mm.

    • Units / UNITS (mm / mil / in)
      Include this parameter to define the type of Units. If it is not defined in ECAD, CoDesigner assumes the values to be in mm.

    • Min. Bending Radius / MIN_BEND_RADIUS
      When specifying values in ECAD, units must not be included. If it is not set in ECAD, MCAD CoDesigner sets the MIN_BEND_RADIUS for wires to 1 mm and cables to 3 mm.

    • Color / COLOR
      If it is not set in ECAD, the default MCAD color is used.

  • In SOLIDWORKS, CoDesigner assigns the properties mentioned above.

  • In PTC Creo, CoDesigner assigns those properties, as well as transferring all other properties defined in ECAD.

MCAD CoDesigner versions 3.10 and higher:

  • CoDesigner uses the following ECAD parameters to configure the corresponding wire/cable properties in MCAD:

    • Thickness / THICKNESS
      In ECAD, the units can be included with the value, or they can be defined by including the Units parameter. If the Thickness is not set in ECAD, MCAD CoDesigner sets the THICKNESS of wires to 1 mm and cables to 3 mm.

    • Units / UNITS (mm / mil / in)
      Include this parameter to define the type of Units. If the Units parameter is specified separately, it overrides the units detected with the Value (a warning is given if the unit types differ). If the Units parameter is specified in in, CoDesigner converts the value to mil in MCAD. If the Units parameter is not defined in ECAD, and there are no units included with the Thickness, CoDesigner assumes the values to be in mm.

    • Min. Bending Radius / MIN_BEND_RADIUS
      In ECAD, the units can be included with the value, or they can be defined by including the Units parameter. If the Min. Bending Radius is not set in ECAD, MCAD CoDesigner sets the MIN_BEND_RADIUS for wires to 1 mm and cables to 3 mm.

    • Color / COLOR
      If it is not set in ECAD, the default MCAD color is used.

  • In SOLIDWORKS, CoDesigner assigns the properties mentioned above.

  • In PTC Creo, CoDesigner assigns those properties, as well as transferring all other properties defined in ECAD.

Connectors

  • As it is not possible to define the physical pins in ECAD (at the moment), those pins should be specified in MCAD by changing the default pins created by CoDesigner (see below). Additionally, in PTC Creo, you can prepare the models with the pins beforehand, and use them through the native ECAD-MCAD component linkage feature.

  • If native ECAD-MCAD component linkage is not used:

    • If there are models stored for connectors in the ECAD library, they will be transferred to MCAD. If not, CoDesigner builds the dummy empty models in MCAD.

    • In SOLIDWORKS, those models are registered in the Routing Library.

    • For newly transferred connectors (the connectors that were not found in the harness project folder or in the MCAD common component folder), CoDesigner builds the dummy physical pins in MCAD:

      • In PTC Creo: the entire set of pins (wire entry ports) according to the ECAD’s pinning, plus an additional cable entry port.
      • In SOLIDWORKS: one connection point for a connector.
    • The mechanical engineer can reorient those dummy pins in the models (and also build the models themselves in the situation where dummy empty models have been used).

    • In SOLIDWORKS, if the models are stored in the common component folder, they will be reused. In PTC Creo, they are always reused.

    • MCAD CoDesigner 3.10 and later, CoDesigner supports the use of non-numeric identifiers for connector pins.

  • In MCAD, CoDesigner assigns the reference designators for the connectors according to what has been assigned in ECAD.

Splices

  • PTC Creo: Splices are represented by Parts with the entry ports created according to the set of wires connected in there. The mechanical engineer will need to change the orientation of entry ports in splices according to the 3D layout of the harness.
  • SOLIDWORKS: Splices are represented by Parts with the connection points created according to the set of wires connected in there. The mechanical engineer will need to change the orientation of connection points in splices according to the 3D layout of the harness.
  • In MCAD, CoDesigner assigns the reference designators for the splices according to what has been assigned in ECAD.

Twists

CoDesigner 3.7 (and later) synchronizes Twisted Pairs with MCAD as Cables, and calculates the physical length of wires considering the Twists per Unit Length and Thickness properties defined in the ECAD Twist object.

The Twists per Unit Length and Thickness are defined as parameters of the ECAD harness Twist object.The Twists per Unit Length and Thickness are defined as parameters of the ECAD harness Twist object.

The untwisted length of each wire is calculated as:

Wire Length (untwisted) = Turn Length x Number of Turns

where:

  • Number of Turns = Twists per Unit Length * Cable Length
    • Twists per Unit Length = number of twists per unit length of cable, defined as a parameter of the ECAD Twist object
  • Turn Length = sqrt((Twist Pitch)^2 + (pi*Thickness)^2)
    • Twist Pitch = 1 / Twists per Unit Length
    • Thickness = outer diameter of the twisted pair, defined as a parameter of the ECAD Twist object

ECAD Connection Points and Harness Topology

In PTC Creo

  • CoDesigner creates Datum Point entities that correspond to ECAD’s connection points (except for the ECAD’s connection points for Connectors).

  • CoDesigner then does the initial physical routing of wires/cables using those points as Location Points.

  • The mechanical engineer can place those points anywhere in the product assembly and create new location points for passing the wires/cables.

  • It is recommended that you do not delete the connection points transferred from ECAD, as they define the harness topology. If such a point is deleted, CoDesigner will try to restore it on the next sync (in the default position in space). However, in some circumstances, it can result in errors.

  • The mechanical engineer can delete and then recreate the physical wires/cables, or, create a Network and then pass physical wires/cables along it. However, the network and wires/cables should still go through the connection points transferred from ECAD in order not to break the harness topology specified in ECAD.

In SOLIDWORKS

  • For each ECAD connection point (except for the ECAD connection point for each Connector), CoDesigner creates a Line of 1 mm length within the 3D route sketch.

  • It’s not recommended to delete the connection points transferred from ECAD as they define the harness topology. If such a point is deleted, CoDesigner will try to restore it on the next sync, however, it can bring errors in some circumstances.

Physical Routing

In SOLIDWORKS

  • Right after getting the initial harness design from ECAD, it's recommended to look into the 3D route sketch created by CoDesigner and clarify where the positions of connection points are, comparing that sketch with the 2D harness topology defined in ECAD's Layout Drawing. Clarity with the topology in 3D sketch will help you to construct the 3D route properly.
  • In some cases, the transitions between the segments in the 3D routing sketch created by CoDesigner are not smooth (the tangency can not be set up correctly). Also, sometimes, SOLIDWORKS can not route some of the physical wires through the 3D routing sketch built by CoDesigner (for example, if there are several routes between two connectors in the sketch, SOLIDWORKS will route the physical wires/cables through the shortest one). These issues can be easily fixed by the user (keeping in mind the importance of connection points transferred from ECAD).

For editing 3D splines in SOLIDWORKS, it is recommended to enable the Enable spline tangency and curvature handles option in the SOLIDWORKS System Options dialog ().

MCAD CoDesigner Harness Workflow Copy Link Copied

In ECAD, the harness is designed as a Harness project. This can be a stand-alone Harness project, or, the Harness project can be created as a child of a Multi-board Assembly project, along with linked PCB projects.

If the Harness is part of a Multi-board Assembly, define the harness that links the PCB modules in the Multi-board schematic editor. Push the Multi-board Assembly project and each PCB project to the Workspace. Learn more about capturing a multi-board schematic, and creating the physical multi-board assembly.

ECAD - Capture the Harness Wiring Diagram

The ECAD harness is captured as a Harness Design project (*.PrjHar). The logical representation of the harness is captured as a Harness Wiring Diagram (*.WirDoc). If the Harness is a child of a Multi-board Assembly project, the parts and connectivity that make up the Harness can be imported from the parent multi-board schematic if each Harness Entry on that schematic has a suitable Workspace Part defined, and the Mated Parts/Pins configured.

If the Harness is a child of a Multi-board Assembly, the Harness Components and connectivity specified in the parent Multi-board schematic can be loaded directly into the Harness Wiring Diagram editor (Design » Import Changes). If there is no parent Multi-board Assembly, place the Harness connector Parts from your Workspace using the Place » Part command. Learn more about Creating a Harness Wiring Component.

If you are importing the Harness from a Multi-board Assembly and the Harness entry connectors and the Mated Parts/Pins are defined on the Multi-board schematic, the Harness connectors will be placed with logical netlines joining the connected pins. These are not editable objects, and they are automatically replaced as you interactively wire the Harness.

Place wires/cables between the connector pins to replace the logical netlines and define the physical connections. Configure the properties of each wire, including THICKNESS, MIN_BEND_RADIUS and COLOR (as shown above), and the Harness is ready for layout. Learn more about Creating the Wiring Diagram.

ECAD - Transfer to Harness Layout Drawing

The physical structure of the ECAD Harness is defined in a Harness Layout Drawing (*.LdrDoc). The Harness Layout Drawing includes the topology of the harness, and MCAD integration (CoDesigner Push-Pull) is done from the Layout Drawing. As long as the connectors are present on the Harness Layout Drawing, the ECAD engineer can Push to MCAD, and the MCAD engineer can then do the 3D cable routing in MCAD.

Add a Harness Layout Drawing to the Harness project, and select Design » Import Wiring Diagram to import the Harness Wiring Diagram. Learn more about Importing the Harness Wiring.

This is the minimum state required for starting MCAD harness integration. The following steps are recommended, but technically not required to make a start.

Define Connection Points (points in space where the harness definition changes), and place a Harness Bundle between each pair of Connection Points. Learn more about Defining the Physical Harness Arrangement.

The default display for the connectors is to show their Graphical Symbol. Use the controls in the Model region of the Properties panel to change to a Physical Model, and then configure how that model is viewed in the Views region of the panel.

Open the MCAD CoDesigner panel, where the defined Harness can be Pushed to the Workspace, ready to be Pulled into MCAD.

MCAD - Create the Device Assembly

If the Harness is being designed as part of the MCAD device assembly, a few steps are required in MCAD to link the ECAD and MCAD assemblies.

  • Open (or create) the MCAD device assembly.

  • If there is a corresponding Multi-board Assembly project in ECAD, click the Link Multiboard button in the Altium CoDesigner panel and select the pushed ECAD Multi-board Assembly project. This action links the ECAD and MCAD assemblies. If your MCAD assembly already includes a PCB, then the Link Multiboard button will not be available in the panel. Instead, you use the Link Multiboard command in the dropdown menu at the top of the Altium CoDesigner panel ().

  • In a linked assembly, CoDesigner will automatically recognize each PCB. Other mechanical parts can also be transferred from MCAD to ECAD by nominating them as belonging to the device enclosure. For example, if your assembly currently includes the product enclosure, select that part/assembly in the MCAD model tree, then in the Altium CoDesigner ribbon, click the Enclosure button. Note that any number of MCAD parts or sub-assemblies can be included as part of the enclosure, including the Harness assembly and the Harness mounting clips.

  • Place the MCAD assembly for each PCB into the MCAD device assembly.

The MCAD device assembly is now ready to add the Harness.

PTC Creo Harness Synchronization

This section outlines the Creo-specific steps to synchronizing the harness design.

SOLIDWORKS Harness Synchronization

This section outlines the SOLIDWORKS-specific steps to synchronizing the harness design.

MCAD – Push the Harness and Multi-board Assembly to ECAD

  • Open the Altium CoDesigner panel. If you are working in the context of the device assembly, the dropdown at the top of panel will list all of the projects that CoDesigner recognizes, select the Harness from the list to make it the active project. You can also synchronize the Harness if the assembly has been opened on its own.

  • Click Push, include a suitable Comment, and click Send to Push the Harness definition to the Workspace.

  • The last step is to Push the entire device assembly to ECAD. In the Altium CoDesigner panel, select the device assembly from the active project dropdown.

  • To include all of the mechanical parts into the enclosure, in the model tree multi-select: the enclosure, the Harness, and all of the clips. You do not need to include the PCBs.

  • On the Altium CoDesigner ribbon, click the Enclosure button ().

  • A confirmation dialog will indicate that this has been successful, and all of the mechanical items will be listed in the panel. If it is not successful, the most likely cause is that the device assembly was not made the active project.

  • CoDesigner does not build or change the Harness Topology in ECAD's Layout Drawing after synchronizing back from MCAD, so the Harness Topology should be specified in that document before back synchronization.

  • In MCAD, the Wire Lengths are calculated automatically, and sent back to ECAD during a Push. The calculated values can be adjusted in MCAD if required, by defining a Corrected Length value in the Length of Harness Objects section of the Altium CoDesigner panel in MCAD. Note that the units displayed in the panel are the current model units. If you change the units, click the Reload Data button () in the panel to refresh the Calculated Length and Corrected Length values.

  • In ECAD, as well as displaying the wire lengths in the Properties panel (when a bundle is selected), wire lengths can also be displayed in the Draftsman document, and the ActiveBOM document, as shown in the image below.

  • If length changes are accepted when the harness is Pulled back into ECAD from MCAD, then the Length Type fields are set to MCAD CoDesigner. With this Length Type setting, the Length Value cannot be adjusted in ECAD unless you switch the Length Type setting to Manual (). 

  • The ability to adjust the wire length in MCAD was added in CoDesigner 3.8.

  • Learn more about Working with Harness Bundles in ECAD.

Auto-calculated wire lengths can be adjusted, if required.Auto-calculated wire lengths can be adjusted, if required.

ECAD – Pull the Harness and Multi-board Assembly to ECAD

  • Each Harness assembly must be synchronized with its ECAD Harness project.

  • If you are synchronizing the MCAD device assembly with the ECAD Multi-board assembly, you must also: synchronize each PCB project from MCAD to ECAD; and update each PCB in the Multi-board Assembly (if they have already been inserted).

  • Performing a Pull in an ECAD Harness project will load the physical lengths of wires, cables, and harness segments into the Harness Layout Drawing.

  • Performing a Pull in an ECAD Multi-board assembly will: pull and apply location and orientation changes for each PCB; load and position all 3D models (in STEP format) that are part of the enclosure; and load and position the Harness as a STEP model.

  • Open the Multi-board assembly in ECAD, then in the MCAD CoDesigner panel, Pull the assembly from the Workspace.

    The Multi-board assembly, complete with boards, harness, and enclosure, can be synchronized between MCAD and ECAD.The Multi-board assembly, complete with boards, harness, and enclosure, can be synchronized between MCAD and ECAD.

Harness Changes that can be transferred from ECAD to MCAD

  • The set of wires and cables.
  • Connectivity information (from-to data).
  • Topology (connection points with the sets of wires and cables going through those points).

Harness Changes that can be transferred from MCAD to ECAD

  • To the Harness Layout Drawing (*.LdrDoc) - The physical length of wires, cables, and harness segments.
  • To the Multi-board Assembly (*.PrjMbd) - The 3D model of the Harness can also be sent to ECAD during Multiboard Assembly synchronization, along with the mechanical enclosure parts.
 
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