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Cable Utilities

Commands:

Use the following functions by first importing the module in your script like this: 

from harnice.utils import cable_utils
then use as written.

cable_utils.new_cable(instance_name, mpn, lib_repo, lib_subpath)

Imports a library cable into the project as a new cable instance.

Creates an instances-list row named instance_name (the cable refdes) and pulls the matching library part into instance_data/cable/{instance_name}/, the same way connectors and backshells are imported.

Args: - instance_name (str): Refdes / instance name for this cable in the project. - mpn (str): Manufacturer part number of the cable in the library. - lib_repo (str): Library repository URL, or "local" for the project library. - lib_subpath (str): Subpath within the library to the cable (may be "").

Raises: - ValueError: If required arguments are blank, or an instance with instance_name already exists. - FileNotFoundError: If the library cable cannot be found.

cable_utils.prepare_for_conductor_assign(instance_name)

Clears system cable-recommendation fields on a conductor so it can be assigned.

System build writes mpn, lib_repo, lib_subpath, cable_group, and cable_identifier onto circuits as suggestions. Those fields are copied onto conductors when the harness is imported. assign_conductor_to_cable requires cable_group and cable_identifier to be blank, and the library identity belongs on the cable instance after new_cable, not on the conductor.

Args: - instance_name (str): Instance name of the conductor to clear.

cable_utils.assign_conductor_to_cable(instance_name, cable_instance_name, cable_identifier)

Assigns a conductor instance to one conductor inside an existing cable.

Verifies that cable_instance_name exists as a cable, that cable_identifier is a conductor in that cable's conductor list, that the conductor instance has blank cable_group and cable_identifier, and that no instance already holds that cable-and-identifier pair. Then writes cable_group, cable_identifier, and appearance onto the conductor, and writes the cable's own appearance (from its attributes JSON) onto the cable instance.

cable_identifier is the identifier column from the cable conductor list. Cable build requires that column to be unique, so it is sufficient on its own.

Args: - instance_name (str): Instance name of the conductor to assign. - cable_instance_name (str): Instance name of the cable created with new_cable. - cable_identifier (str): Conductor in the cable (identifier column).

Raises: - ValueError: If the conductor or cable is missing, the cable has no conductor list, cable_identifier is missing or not unique, the conductor is already assigned, or that cable conductor is already assigned to another instance.

cable_utils.map_cables_and_conductors_to_segments()

Routes every conductor and cable onto the flattened network and writes lengths.

Conductors are mapped from node_at_end_a to node_at_end_b. Cables have no ends of their own: each cable is mapped onto the segments shared by every conductor assigned to it (the jacketed run before conductors break out to different nodes). Those shared-path ends are written onto the cable as node_at_end_a / node_at_end_b. Then writes length on each conductor (sum of its conductor-segment lengths) and on each cable (longest member conductor).

Raises: - ValueError: If a conductor cannot be mapped onto the network (see flattened_network.map_instance_to_segments).

cable_utils.calculate_bundle_diameter(segment_instance_name)

Estimates the outer diameter of a segment from the cables it carries.

Collects every cable mapped onto segment_instance_name (via cable-segment hops from map_cables_and_conductors_to_segments) and reads each cable's jacket OD from its attributes JSON — a stated od, or a pack of member od / AWG values when the jacket does not give one. Conductors on the segment that are not inside one of those cables (broken out, or never assigned) are included by their own conductor OD. If an unassigned conductor has no od, diameter, gauge, or attributes JSON, it is counted as 0.2 in and that assumption is printed.

Bundle OD is d_av * β: average member OD times Stringer's empirical bundle factor for that member count, linearly interpolated where the table has no exact entry. The result is written to the segment's diameter column (inches) and returned.

Stringer, E. J. (Rockwell International Corp.). "Calculating Wire-Bundle Diameter." NASA Tech Briefs 3, no. 1 (June 1978): 127. Tech Brief B78-10119. Report MSC-16378. https://ntrs.nasa.gov/citations/19780000119

Call this after map_cables_and_conductors_to_segments.

Args: - segment_instance_name (str): Instance name of the segment to size.

Returns: - float: Estimated bundle OD in inches.

Raises: - ValueError: If the name is blank, the instance is missing or is not a segment, a cable on the segment has no usable OD, or an assigned conductor has no od / gauge.