Connectors

Backshells

and Backshell Terminations

In Capital Systems Integrator, there are various actions that you can perform for a backshell. A backshell is housing on a connector that covers the rear portion where the cable conductors connect to the connector contacts.

You can:

Select a backshell part number and backshell terminations for a slot connector, inline connector or interface connector.
Select which shield terminations terminate at backshell terminations instead of a slot connector or inline connector.
Use the backshell/connector association when defining harness connector footprints.
Use the Backshell Termination by Attribute/Property and Pigtail Usage by Attribute/Property constraints to define backshell termination rules for slots so that wiring synthesis takes backshells into consideration. See Overview of Rules and Constraints for more information about these constraints.

Holes cannot have backshell terminations.

If a backshell symbol is associated with the backshell library part in Capital Component Manager, Capital Schematic Generator for Systems Integrator does not use the backshell symbol when generating wiring diagrams.

Backshell Terminations Design

Flows

Flow without a harness connector footprint

You create a functional Capital Logic Designer design and terminate multicore shield terminations to a pin on a device.
You create a Capital Systems Integrator design, associate the logical design and place devices according to the rules and constraints defined for slots.
Designate connector cavities to be used as backshell terminations. Note A single connector can have only one backshell but it can have multiple backshell terminations.

There are two ways to do this: Add a Backshell Termination by Attribute/Property constraint to slot connectors and inline connectors. See Overview of Rules and Constraints for more information about using rules and constraints. When placing a device, the system examines this constraint to determine when and how to use backshell terminations instead of normal cavities. The system indicates any backshell terminations in the Signal Map dialog box for the slot. See Connector Refinement and Signal Mapping.

Manually add backshell terminations to slot connectors and inline connectors. See Adding a Backshell Termination to a Connector.

Select the appropriate slot connector or inline connector and assign a connector part number, appropriate backshell and backshell terminations. Backshells display in the Design Browser (Design tab) under the slot connector or inline connector. Note Designated cavities that belong to the same backshell are electrically connected in the signal map. If you select more backshell terminations than there are designated cavities, the system creates new designated cavities and updates the signal map accordingly.
Synthesize wiring. The system takes any constraints on objects into account to decide whether to create backshell terminations. Note that this step could be run before step 4 and would have to be run before step 4 in the case of inline connectors because the system does not create inline cavities until wiring synthesis is performed. When the router determines that a shield needs to terminate at a particular cavity, the cavity is examined to see if there is a Backshell Termination rule on the backshell termination (or above in the rule-hierarchy). If so, the rule is used to determine if the connection is made with a pigtail or not. By default, a pigtail is used. Wires that route to the designated backshell cavities connect to physical backshell terminations instead of the connector pins. When wiring is synthesized, the necessary cavities may not exist yet (for example, on an inline). In this case, the connector is examined for rules to determine if, and how, a shield conductor should terminate. For slot connectors on slots, the system expects the backshell terminations to exist already (as in step 3 of this design flow). For inline connectors and junction boxes, the backshell terminations probably do not exist prior to wiring synthesis. The system uses the backshell termination rule on the inline connector (or above in the rule hierarchy) to determine whether to use backshell terminations for terminating a signal on an inline. You can use the Signal Map dialog box to edit the mappings after synthesis. See Connector Refinement and Signal Mapping for more information about this facility.
Optionally, change the pigtail type termination to a regular shield termination. See Modifying a Shield Termination.

Flow with a harness connector footprint

Create a harness-side device footprint in Capital Component Manager.
Create a functional Capital Logic Designer diagram that uses devices with the harness-side device footprint.
You create a Capital Systems Integrator design, associate the logical design and place devices according to rules and constraints defined for slots. When you place the devices with footprints in Capital Systems Integrator, the system recognizes the default backshells with all their terminations and designates corresponding cavities on the slot connectors. The system determines backshell usage based on Integrator rules and constraints, not library information. Backshells display in the Design Browser (Design tab) under the slot connector or inline connector. Signal mapping information is restricted if library parts are assigned.

Design Rule Checks Related to Backshells

You can run design rule checks to determine if there are rule conflicts on cavities. See Running Design Rule Checks Manually for more information about running checks. You can run the following checks with regard to backshells:

Signals that break backshell usage rule Identifies backshells where a cavity should be used according to assigned rules and constraints.
Signal that breaks pigtail usage rule Identifies signals that connect using a pigtail, where no pigtail should be used according to assigned rules and constraints. Also identifies signals that connect without a pigtail, where a pigtail should be used according to assigned rules and constraints.

Parent Topic:

Connectors