QuickNav - Schematic Design Objects

Part

A part (or component) within a library represents the physical device that is placed on the actual printed circuit board. On a schematic sheet, a component is represented by its schematic symbol model. Each component can contain one or more parts. Along with a symbolic representation of the component the part also includes links to models, such as the PCB footprint, and also parameters that are used to document details such as component parameters and supplier information. How the model links and parameters are added to the part depends on the type of library storage being used. Learn more...

Part Designator & Comment

The Designator field is a child parameter object of a schematic component (part). It is used to uniquely identify each placed part to distinguish it from all other parts placed across the schematic source documents of the project. Learn more...

The Comment field (also a child parameter object of a schematic component (part)) is used for displaying additional information for the component (such as part number or value). Learn more...

Power Port

A power port creates connectivity to every other power port of the same name throughout the schematic project, regardless of the design structure. The net is automatically named by the power port. This net can be localized to a specific schematic sheet if required. Learn more...

Wire

A wire is a polyline electrical design primitive that is used to form electrical connections between points on a schematic. A wire is analogous to a physical wire. Learn more...

Net Label

A net label is a net identifier used to create connectivity to other net labels with the same name on the same schematic sheet. The net is automatically named by the net label. Net labels can be placed on component pins, wires and buses. Note that net labels do not connect between sheets unless the project options are configured to use a Net Identifier Scope of Global. Learn more...

Port

A port is used to connect a net from one schematic sheet to another. Connectivity can be vertical (in a hierarchical design) or horizontal (in a flat design). Port names are used to name nets if the Allow Ports to Name Nets option is enabled on the Options tab of the Project Options dialog. In this situation, ports will also connect within the same schematic sheet. Learn more...

Offsheet Connector

An offsheet connector is used to connect a net from one schematic sheet to another sheet (not within the same sheet). They only support horizontal connectivity (flat designs) and have limited functionality when compared to ports. Learn more...

Sheet Symbol

A sheet symbol is used to represent a sub-sheet in a multi-sheet hierarchical design. A hierarchical design is one where the structure – or sheet-to-sheet relationships – in the design is represented. The advantage of the hierarchical design is that it shows the structure of the design and that the connectivity is completely predictable and easily traced since it is always from the child sheet up to the sheet symbol on the parent sheet. Another advantage of a hierarchical design is that it provides the platform for the delivery of a sophisticated design reuse system. This system is delivered through either managed schematic sheets or device sheets, depending on whether the system is Workspace-based or file-based. In each case, the symbol placed differs in its coloring and includes a graphic to distinguish it as referencing a reusable entity, but the functionality and behavior are essentially that of the standard sheet symbol. Learn more...

Sheet Entry

A sheet entry is placed within a sheet symbol to create connectivity to a port of the same name on the source schematic sub-sheet that the symbol represents. Sheet entries are used as net names if the Allow Sheet Entries to Name Nets option is enabled in the Options tab of the Project Options dialog. Learn more...

Sheet Symbol Designator

The sheet symbol designator, which is a child object of the parent sheet symbol, is used to provide the symbol with a meaningful name that will distinguish it from other sheet symbols placed on the same schematic sheet. Typically, the name will reflect the overall function of the schematic sub-sheet that the symbol represents. By using sheet symbol instantiation, multiple channels on the same sub-sheet can be referenced from a single sheet symbol. The syntax used involves the use of the Repeat keyword in the sheet symbol's Designator field. Learn more...

Sheet Symbol File Name

The sheet symbol file name is a child object of the parent sheet symbol and provides the link between the sheet symbol and the schematic sub-sheet that the symbol represents. Multiple sub-sheets may be referenced by a single sheet symbol by separating each filename with a semi-colon in the File Name field. Learn more...

Signal Harness

A signal harness is an abstract connection that enables the logical grouping of different signals, including buses, wires, and other signal harnesses, for increased flexibility and streamlined design. Signal harnesses allow for the creation and manipulation of higher-level abstract connections between sub-circuits in PCB projects. They allow for a more complex design within the same schematic design space, which increases the readability of designs and builds potential for reuse. Learn more...

Harness Connector

A harness connector is essentially a container that groups various signals together to form a signal harness, including buses, wires, and other signal harnesses. Think of a harness connector as a funnel that gathers all of the signals that connect to this harness through the included harness entries. Learn more...

Harness Entry

A harness entry is placed within a harness connector and is the connection point through which signals – through wires, buses and other signal harnesses – are combined to form a higher-level signal harness. Learn more...

Harness Type

The harness type, which is a child object of the parent harness connector, is used to name the type of placed harness connector or the set of harness entries defined within it. The harness type and its associated harness entries are essentially the names of the containers that carry the nets, not the names of the nets themselves. Learn more...

Pin

Pins are placed in the Schematic Library editor to represent the physical pins on the component. Only one end of the pin is electrically active, which is sometimes referred to as the hot end of the pin. Learn more...

Probe

A probe is used to take measurements at specific locations of a simulation-ready circuit. Probes can be used to interrogate the voltage, current or power at an applicable location, and even a voltage differential (using two sequentially-placed probes). You can also enable interactive mode for probes to immediately reflect any changes (adding/removing probes, enabling/disabling probes, moving a probe to a different location, changing probe color) in the .sdf document containing the simulation results without re-running the simulation each time. Learn more...

No ERC Directive

A no ERC design directive is placed on a node in the circuit to suppress all reported Electrical Rule Check warnings and/or error violation conditions that are detected when the schematic project is validated. Use no ERC to deliberately limit error checking at a certain point in the circuit that you know will generate a warning (such as an unconnected pin) while still performing a comprehensive check of the rest of the circuit. Learn more...

Differential Pair Directive

A differential pair directive (a predefined parameter set directive) allows you to define a differential pair object on the schematic. Attach a directive of this type to both the positive and negative nets of the intended pair or cover the pair with a blanket object to target multiple nets with a single directive. The nets themselves must be named with the suffixes of _P and _N. Custom differential pair suffixes can be defined in the Diff Pairs section on the Options tab of the Project Options dialog.

Each pair of directives (one for the positive net and one for the negative net) of this type will yield a differential pair object when transferred to the PCB during the synchronization process. Each of these differential pair objects will be added to the default differential pair class of All Differential Pairs. The name of a generated differential pair object will be the root name for the net pair on the schematic. For example, directives added to USB_N and USB_P on the schematic in the example above will generate a differential pair object on the PCB with the name USB. You can rename differential pair objects on the PCB side only. Learn more...

Parameter Set Directive

A parameter set directive allows design specifications to be associated with a net-type object within a schematic design. For example, use a parameter set directive to define PCB layout constraints, differential pairs and net classes. It is the presence of specifically-named parameters in the parameter set directive that the software uses to determine which design directive you are placing. Learn more...

Blanket Directive

Where a parameter set directive can only target the specific net that it is attached to, when combined with a Blanket directive, its scope can be expanded to cover all nets within the blanket. A blanket directive is placed over a collection of nets and/or components. You can either define a simple rectangular shape or a polygonal shape. The latter gives more precise control over the coverage of the required net objects on a sheet. A parameter set directive applied to the blanket will then apply to all nets and components that the blanket covers. Learn more...

Compile Mask Directive

No ERC directives are great for suppressing a low number of violating pins, ports, sheet entries, or nets within a design. However, in some cases, it may be desirable to remove an entire section of the design, including components. Use a compile mask directive to effectively hide the area of the design it contains from the Compiler (when performing a manual validation), allowing you to manually prevent error checking for circuitry that may not yet be complete and will generate compile errors. This can prove very useful if you need to validate the active document or project to check the integrity of the design in other specific areas but do not want the 'noise' of compiler-generated messages associated with unfinished portions of the design.

This feature can also be put to great use when simulation is included as part of the design flow, as in the example above. Voltage and current sources are necessary elements when running circuit simulations, but they have no place on the completed PCB. By applying a small amount of planning to the structure of the circuit, it is usually possible to group all simulation-specific components in one section of the design that can then be easily covered by a compile mask directive. Learn more...

Comment

A comment is a user-added note that is assigned to a specific point, object, or area (as applicable) on a supported document type and may be replied to by other users. Comments promote collaboration between users without altering the shared data itself because comments are stored by the connected Workspace independently of that data. Comments are posted, replied to, and managed directly within the main design space using a contextual commenting window in conjunction with the Comments and Tasks panel. Learn more...