Using Routing applications > Routing Electrical > Routing Electrical best practices

Defining splices

A splice is any means by which two or more wires connect along a path in a harness design. The connection may be made by a physical device, or the wires may be attached to each other directly (soldered, twisted, and so forth). A wire involved in a splice may end at the splice or it may pass through the splice.

Splice component qualification

Create a splice component, required to represent the splice whether physical or virtual. A virtual device carries information necessary to support the electrical relationships of the splice but has no solid body. A physical device carries similar electrical information but also has a solid body.

Use Qualify Part to add a fixture port to a splice component. The fixture port allows you to position the component along a path. Create a number of connection ports on the component — as many as the number of wires terminating there — rather than a device with a fixed pin layout.

Connection List (.hrn) content

Each wire that terminates at the splice has an entry in the Connection List with either the from connector or the to connector having the value of the splice component's unique identifier (as provided by the Electrical Component Navigator).

An entry in the Connection List for a wire that passes through the splice, but does not terminate there, has no reference to the splice — define this wire as if it had nothing to do with the splice.

Note: In the 3D model, it is not possible to determine which wires in the bundle, if any, pass through a splice.

Example: Wires A, B, and C are defined in the connection list as being from C1 to C2. Wire D is defined as being from C1 to S1. The model does not contain the information that Wire C passes through S1 (a splice).

Splice component placement

Determine where you want to place the splice in the harness by whatever design criteria applies. Subdivide the path segments at that location, which creates an RCP. If the splice component has no solid body, there is no display indicating that the component is present — this does not pose a problem when assigning components, since the fixture port becomes visible as the cursor drags over the component (or you can select it from the ANT).

Routing the wires

A wire that terminates at a splice routes the same way other wires are routed, using either Auto Route or Manual Route. Typically, the bundle diameter on one side of the splice is larger than the bundle diameter on the other side, since one or more wires stop at the splice.

Example: Connector 1 is connected via a bundle of wires 2 to a component 3, used as a splice. Wires 4 and 5 branch out from this splice and connect it to connectors 6 and 7. The diameter of the bundle of wires 2, and of wires 4 and 5, depends on the bundle design and may or may not be correlated.

Formboard

The splice component carries to the formboard model. If a virtual splice component is used, place a note at the splice location to indicate to the builder where the splice occurs. If a physical splice component is used, the component appears on the formboard drawing, which should be annotated accordingly.

Connection List display format

Intermediate component smart fields are used to view splice information in the Connection List Navigator. The splice smart fields have specific base names:

intermed_comp
intermed_conn
intermed_pin

Before viewing the splice information, you need to add the field names in the Format Settings dialog box. The field names should be base name_n, where n starts with integer 1 and increments by one with each next splice added in the network.

Example: field names for the first splice component placed on a path should be intermed_comp_1, intermed_conn_1, intermed_pin_1. Field names for the fifth splice component placed on a path should be intermed_comp_5, intermed_conn_5, intermed_pin_5.