Harness length

Wire, cable, ribbon cable, or segment length in a harness assembly is the basic length of the object depending on its position within the harness assembly. With wires, for example, the length is calculated as the distance from pin to pin based on the path the wire takes as it is routed through the segments.

Other factors also contribute to the overall length of the objects. These factors cause adjustments to the original length.

What factors contribute to adjusted length?

The adjusted length accounts for the original length of the harness object, with the addition of one or more of the following:

• Embedded Length - the amount a wire, cable wire is inserted into a part, splice, or pin. For ribbon cables it is the amount the ribbon cable is inserted into the part.
• Global Slack - adds extra length to all wires, cable wires, and ribbon cables contained in the harness assembly. The value is a percentage of the existing wire, cable wire, or ribbon cable original length, which is used to accommodate potential variations in length.
• Round-Up - a value that increases the length of wires, cables, and segments by a set increment. It is used to ensure a length that is easily measured and cut.
• Service loop - a custom property on a harness segment that adds extra length to the segment and all wires contained in the segment.

How are round-up and global slack applied?

Global slack is applied to the original harness object's length before round up or embedded length are included. Round-up is applied after all other adjusted length options have been figured into the wire, cable, ribbon cable, or segment length calculations. Only the adjusted length values, not the original length, are rounded up to the nearest specified increment value.

Note: Round-up is reset to None if the units of measurement are changed for the harness assembly.

The displayed value of the adjusted length is a result of both the round-up value and the document significant digits. For example, if a round-up of 0.125 is used and the significant digits are set to 2 digits or less, the adjusted length is calculated with the round-up applied. The system then displays the value according to the document significant digits setting.

When round-up is set to a value other than None, the Apply round up to individual segments and exposed wire lengths setting provides additional control over a routed wire's adjusted length and how entities are dimensioned in the nailboard. This setting is needed when:

• The adjusted lengths of the segments must be rounded.
• The individual dimension value for the entities is not rounded.

What is the effect of embedded length on overall length?

If an embedded length property exists on a part, splice, or pin, the value of the property is added to the harness object's adjusted length. If both pins and parts and splices are selected, the value on the pin overrides the value on the part or splice. This is useful for connectors that have different pin or cavity sizes. For splices, embedded length indicates the type of splice being used. If pins, and parts and splices are deselected, embedded length values are ignored.

Embedded length values are assigned at either the definition or occurrence level for parts, splices, and pins.

How does adjusted length affect the nailboard?

The adjusted length values for the nailboard are inherited from the assembly to draw and dimension the harness objects, even if the nailboard and harness assembly units differ.

Changing the global slack in the harness assembly affects the adjusted length value that is passed to the nailboard for the wire, cable wire, and ribbon cable lengths. The global slack and round-up settings cannot be changed in the nailboard drawing.

How is cable adjusted length determined?

The adjusted length for routed cables is the length of the segment path the cable takes, plus the longest cable wire stub from each end of the cable. The adjusted length of the cable wires are used to determine the longest conductor stub set.

The length of an unrouted cable is the length of the longest cable wire.