Schematic Placement & Editing Techniques

• Horizontal Alignment - choose from one of the following options to determine the horizontal alignment of the selected objects:
  • No Change - leave the horizontal alignment of the objects unchanged.
  • Left - align objects to the left edge of the left-most object.
  • Center - align objects on an axis mid-way between the left-most and right-most objects in the selection.
  • Right - align objects to the right edge of the right-most object.
  • Distribute equally - horizontally space the selected objects evenly, using the left-most and right-most objects as the left and right boundaries respectively.
• Vertical Alignment - choose from one of the following options to determine the vertical alignment of the selected objects:
  • No Change - leave the vertical alignment of the selected objects unchanged.
  • Top - align objects to the top edge of the top-most object.
  • Center - align objects on an axis mid-way between the top-most and bottom-most objects in the selection.
  • Bottom - align objects to the bottom edge of the bottom-most object.
  • Distribute equally - vertically space the selected objects evenly, using the top-most and bottom-most objects as the top and bottom boundaries respectively.
• Move primitives to grid - enable this option to restrict the alignment such that all primitives in the selection will lie on a valid grid point after the alignment is complete.

The Part represents the actual physical electronic component.

Summary

A Part is an electrical design primitive. It is a schematic symbol that represents an electronic device, such as a resistor, a switch, an operational amplifier, a voltage regulator, etc. Parts are stored within components in schematic component libraries. Note that 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.

Availability

Parts are available for placement in both the schematic and schematic library editors.

• In the schematic editor, click Place » Part.
• Right-click in the design space then choose Place » Part from the context menu.
• From the Components panel, right-click on a component and select Place <ComponentName>.

• From the Components panel, select a Generic Component as a placeholder.

  When connected to an Altium 365 Workspace, note that the Generic Components functionality is not supported with the Altium Designer Standard Subscription.

• Dragging and dropping a component from the Components panel.
• Select the Place button in the Details pane of the Components panel, or by using the Enter hotkey.
• From the SCH Library panel when in the schematic library editor, select a component, then click Place.

Placement from the Components Panel

In the schematic editor, the part selection and placement process may be done from the Components panel.

• The panel displays the contents of the currently selected library. Use the drop-down next to the library name to choose another library.
• Use the mask field below the currently selected library field to filter the list and speed the searching process or scroll and select the required part.
• Click Place, double-click, or click and drag to place the selected component onto the active schematic sheet. While the part is floating on the cursor, it can be rotated (press Spacebar), mirrored along an axis (press X or Y), or edited (press Tab) before placement.
• The columns shown in the list of components in the currently selected library can be reorganized (click and drag) or reconfigured (right-click, then choose Select Columns).
• Click the  button within a Generic Component tile to attach the component to the cursor for placement in the active Schematic document. Selecting the tile itself will open that component type category in the Components panel.

Searching for a Component

The non-Workspace library menu options provide you the ability to set preferences, perform searches, and migrate database and file-based library content. To access these options, select the library menu button at the top right of the Components panel.

Select File-based Libraries Preferences to open the Available File-based Libraries dialog, where you may view controls to add or remove libraries, install libraries, and specify library search paths.

The current listing of database and file-based library components may be filtered by entering a search phase in the Components panel Search field. To access more advanced search capabilities for component libraries, select the File-based Libraries Search option from the panel’s menu (top right), which opens the File-based Libraries Search dialog. The dialog offers flexible search options including query-based filter constraints, and the ability to search through all available database and file-based libraries or those within a specified path.

• The default search Scope is to search for Components in the Available File-based Libraries.
• Alternatively, the dialog also supports searching through Libraries on path stored in folders on a drive. To do this, enable the Libraries on path option then configure the Path options as required.
• The Filters use "AND" and, therefore, it is better to start with a simple filter and if there are many results, use the Refine last search mode to search within the results.
• Query search results are presented in the File-based Libraries Search dialog when selecting Helper.

Placing from the Schematic Library Editor

A Part also can be placed directly from a library that is open in the schematic library editor from the SCH Library panel. Note that:

• Clicking the Place button in the panel will place the selected part (component) in the last active schematic sheet.
• While the part is floating on the cursor, it can be rotated (press Spacebar), mirrored along an axis (press X or Y), or edited (press Tab) before placement. The action can also be performed while dragging the object. Rotation is in increments of 90°.

• If a part is placed directly from a library, that library does not need to be added in the Available File-based Libraries dialog first.

  

Graphical Editing

Graphical editing for a part is limited to moving, rotating, and mirroring. When a part is selected in the design space, a dashed selection box will appear around it. To graphically manipulate a selected component:

• Press Delete to remove the selected part from the design.
• Click and hold to move the selected part. The cursor will jump to the nearest electrical hotspot (the wiring end of the nearest pin).
• Press the Spacebar to rotate the arc counterclockwise or Shift+Spacebar for clockwise rotation. The action can also be performed while dragging the object. Rotation is in increments of 90°.
• While a part is moving on the cursor, press the X or Y key to mirror it along that axis.

A selected Part

Working Between the Schematic Component and the PCB Component

The software includes tools to help work between the component on the schematic and that same component on the PCB. These tools include Cross Probing, Cross Selection, and Selecting the PCB Components from the schematic.

Cross Probe

As the name implies, Cross Probe allows you to click on a component in one editor and jump to that component in the other editor. To Cross Probe:

• Click Cross Probe located on the schematic or PCB editor menu on the Tools menu.
• When you click the component in the schematic editor, it will be centered and zoomed in the PCB editor. The zoom level is set on the System – Navigation page of the Preferences dialog.
• The default behavior is to remain in the same editor, ready to cross probe another component. To switch to the other editor as you Cross Probe, hold the Ctrl key.

Cross Select Mode

Cross Select Mode selects the same component in the other editor. Note that it does not zoom and center. Cross Selection is either on or off. Click Tools » Cross Select Mode to toggle the mode on/off. Select multiple components by holding the Shift key as you click to select.​

Selecting the PCB Components

This feature allows you to select multiple schematic components in a specific order, then place those same components in the PCB editor in the same order. To use this feature:

• Select the components on the schematic one by one (hold Shift as you click to select multiple components).
• Switch to the PCB editor then press the I, C shortcut to launch the Reposition Selected Components command. The Reposition Selected Components command is also available on the right-click menu after pressing the I shortcut.

General Tab

General

• Reuse Block – when the component is a part of a reuse block, this field shows the name of the parent reuse block. Click the Reuse Block hyperlink to see the properties of this reuse block.
• Designator – enter the designator. Toggle the eye icon to show/hide the designator. Use the lock icon to lock/unlock the designator.
• Comment – enter the name. Toggle the eye icon to show/hide the name. Use the lock icon to lock/unlock the name.
• Part <x> of Parts – displays the number of the selected part and the total number of parts. Use the drop-down to select the number of the associated part then enter the total number of parts. Click to lock/unlock the fields.
• Description – the component/part description.
• Type – select one of the following component types for the component footprint here. The available types are:
  • Standard – components that possess standard electrical properties, are always synchronized between the schematic and PCB (the footprint, pins/pads, and net assignments must all match), and are included in the BOM. An example is a standard electrical component, such as a resistor.
  • Mechanical – components that do not have electrical properties, are not synchronized (you must manually place them in both editors), and are included in the BOM. An example is a heatsink.
  • Graphical – components that do not have electrical properties are not synchronized (you must manually place them in both editors), and are not included in the BOM. An example is a company logo.
  • Net Tie (In BOM) – components that are used to short two or more different nets together, are always synchronized between the schematic and PCB (the footprint, pins/pads, and net assignments must all match), and are included in the BOM. They differ from a Standard component in that connectivity created by copper within the footprint is not checked; it is this copper that allows the nets to be shorted. Note: enable the Verify Shorting Copper option in the Design Rule Checker dialog to verify that there is no unconnected copper within the component.
  • Net Tie (No BOM) – components that are used to short two or more different nets together, are always synchronized between the schematic and PCB (the footprint, pins/pads, and net assignments must all match), and are not included in the BOM. They differ from a Standard component in that connectivity created by copper within the footprint is not checked; it is this copper that allows the nets to be shorted. Note: enable the Verify Shorting Copper option in the Design Rule Checker dialog to verify that there is no unconnected copper in the component.
  • Standard (No BOM) – components that possess standard electrical properties, are always synchronized between the schematic and PCB (the footprint, pins/pads, and net assignments must all match), and are not included in the BOM. An example is a testpoint component that you want to exclude from the BOM.
  • Jumper – components that are used to include wire links in a PCB design, for example, on a single-sided PCB that cannot be fully routed on one layer. For this component type, the component footprint and pins are synchronized between the schematic and PCB but the net assignments are not, and the component is included in the BOM. As well as selecting this option at the component level, both of the pads in the component must have their JumperID set to the same non-zero value. Jumper type components do not need to be wired on the schematic; they only need to be included on the schematic if they are required in the BOM. If they are not required in the BOM, they can be placed directly in the PCB where the Component Type is set, the JumperIDs are set, and the Nets manually assigned for the pads.
• Design Item ID – this field lists the name of the component selected. Click to open the Replace Component (Workspace) dialog or Replace Component (non-Workspace) dialog, depending on whether a Workspace or non-Workspace component is being edited. This dialog grants access to full details of the selected component (Parameters, Models, Part Choices, Supplier data, etc.), component comparison, and the ability to replace the current component with another, among other possibilities. If another component is selected as a replacement, this field will then display the full Design Item ID for the newly selected component. Click the Validate button () to display information regarding where the component resides. If it is a non-Workspace component, the file path in which it is saved on your computer will appear. If it is a Workspace component, the information will indicate that the component was simply found.
• Source – displays the name of the source library of the component. Click  to search for and select the desired library.

• Revision state – this field displays the current lifecycle state of the selected component revision, with the color icon and name of the revision state.

  When connected to an Altium 365 Workspace, note that configuration and use of lifecycle definitions is not supported with the Altium Designer Standard Subscription.
  If a component used in a design (or managed schematic sheet) has been deleted, this will be indicated at the bottom of the General tab in the Properties panel by the associated icon.

• Revision status – if the selected component revision is in an applicable state (allowed for use in designs) the entry will either reflect that the revision is the latest (Up to date) or not (Out of date). If the revision is in an inapplicable state (not allowed for use in designs) the entry will display Not applicable. Click the button to update the component to the latest revision.

  When clicking the button and not all parts of an out-of-date multipart component are selected, you will be prompted to update all parts of this component. Click Yes in the Confirm dialog that opens to continue.

• Component issues (Properties panel only) – if a selected component sourced from the connected Altium 365 Workspace has any health issues, an indication of this will be presented by the (for errors) or (for fatal errors) icon. The number at the right of the icon indicates the number of found issues. Click the down arrow at the right of the number to see the short descriptions of the issues.

  
  An example of library health issues found.

  Your Workspace library health can be explored in more detail through the Library Health dashboard page accessible from the Altium 365 Workspace browser interface. See Library Health Dashboard to learn more.
• Supply Chain Data (Properties panel only) – this field displays the supply chain information from related Part Choice:
  • Median unit price. This entry will be displayed in red text if there are no prices, or the price = 0.
  • Stock. This entry displays the total sum of the stock available from the suppliers enabled as part of the Altium Parts Provider source for your Workspace.
  • Manufacturer Lifecycle Bar. Hover over the bar for an informative tool-tip. This can appear in one of four states:
    • White/Gray = Default, unknown or no information
    • Green = New or Volume Production states
    • Orange = Not Recommended for New Design
    • Red = Obsolete or EOL

    The manufaturer lifecycle status is designed to be used as an indicator, for a number of reasons:

    • Altium maintains a database of many millions of components, produced by thousands of component manufacturers. Since there is no single, consistent method used by those manufacturers to reflect a component's lifecycle state, the status is based on information aggregated from manufacturers, global distributors and global sales analysis.
    • A part is only reported as EOL or Obsolete when there is at least one authorized distributor or manufacturer that has confirmed this status.
    • Determining the Not Recommended for New Design status is more complex. Manufacturers sometimes just report if a part is active or not, and may not give advance warning that a part is to be discontinued or replaced. Therefore this lifecycle status does not always concur with the status provided by the manufacturer. The status algorithm uses various information, including real time and historical stock availability from all distributors, to try to determine the availability of the part. Parts which have consistently poor availability (when they have been generally available in the past), or cannot be sourced over a period of time after having previously having good availability, will eventually be flagged as Not Recommended for New Design (if they are not already EOL or Obsolete).
    • The idea of the lifecycle status indicator is to provide simple-to-understand information that helps you to make more informed decisions about a part, by highlighting those parts which may be problematic. However, due to the sheer volume of data and number of components that are managed, there is always a chance that the Altium status lags behind the instantaneous manufacturer status, and is therefore not up-to-date. It is not possible for Altium to guarantee the accuracy of the lifecycle status, it is recommended that if there is any doubt that you double-check with the manufacturer for authorized lifecycle information.

Location

• (X/Y)
  • X (first field) – the current X (horizontal) coordinate of the reference point of the object, relative to the current design space origin. Edit to change the X position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default.
  • Y (second field) – The current Y (vertical) coordinate of the reference point of the object, relative to the current origin. Edit to change the Y position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default.
• Rotation – use the drop-down to select the rotation. Choices are 0 Degrees, 90 Degrees, 180 Degrees, and 270 Degrees.

Parameters

• Grid – lists the Name and Value of the parameters associated with the currently selected component. Use to lock/unlock a listed parameter. Parameter values can be manually entered, or selected from a drop-down menu list that offers values sourced from all the available components of that type. You may toggle the eye icon to show/hide the parameter.

• Favorites – parameters marked as Favorites will be shown in the Parameters list, while those not marked will be hidden. Hover to the right of a parameter filter’s name and click the  icon to set the filter as a Favorite. To remove a parameter as a Favorite, click the icon again.

  To see all hidden parameters, click the Show More link at the bottom of the list. Click the Show Less link to view Favorite parameters only.
  This feature is available by enabling the Schematic.UI.ShowMoreOrLessParameters option in the Advanced Settings dialog. When this option is disabled, the Favorite parameters and the Show More/Show Less features are disabled, resulting in all of the component parameters always being displayed in the Component mode of the Properties panel.
• Font – click on the displayed font to change the font style.
• Other – click to open a drop-down to change additional options:
  • Show Parameter Name – enable to show the parameter name.
  • Allow Synchronization with Database – enable to synchronize with the database. This option is used to control if the comment can be updated. By default, these options are enabled to always allow synchronization with the source library/database. You may disable this option to prevent that comment from being included in an update process.
  • (X/Y) – enter the X and Y coordinates.
  • Rotation – use the drop-down to select the rotation. Choices are: 0°, 90°, 180°, and 270°.
  • Autoposition – check to enable auto-positioning, meaning that the parameter is positioned automatically every time the associated component is rotated. Disable this option to keep the parameter position to the associated component when it is rotated.
• Add – click to add a parameter, such as a footprint, model, or rule, among others. Click  to delete a selected entry from the grid. Click to edit the parameter via the parameter's respective dialog.

Graphical

• Mode – use the drop-down to select the desired mode. If no modes other than Normal are available, this drop-down will be grayed out.
• Mirrored – enable to mirror the part.
• Local Colors – enable the local color option and the schematic component's fill, line, and pin colors are overridden with the colors from the Fill, Lines, and Pins color boxes respectively. Disable this option to use the predefined colors from the library.

Part Choices

• Part Name – click to be lead to additional information about the part, provided directly from the supplier.
• Datasheet – click this button to be lead to the product's latest information, directly from the supplier's website.
• SPN(s) – an SPN (Supplier Part Number) contains the following information:
  • Colored tile banner showing the supplier name and price. The color reflects the risk associated with choosing that supplier. The risk can change at any time based on the availability and price data received from the Altium Parts Provider.
    • Green = Best
    • Orange = Acceptable
    • Red = Risky
  • Supplier part number (linked to the part on the Supplier's website)
  • Last updated icon with details displayed in the tooltip, color indicates:
    • White/Gray = Default, updated less than one week ago
    • Orange = 1 week < last update < month ago
    • Red = last update > 1 month ago
  • Country code for the Supplier location (ISO alpha 2); colored red if unknown.
  • Part source, details displayed in the tooltip.
  • Stock quantity; red if no stock available.
  • Unit price, red if no price available. Unit price includes currency icon, currency is determined by the location of the supplier.
  • Available price breaks, with Minimum Order Quantities.

Pins Tab

• Grid – this region lists the Pins and Names for all the pins of the selected component. Use the eye icon to show/hide the pin. Use the lock icon to lock/unlock the pins.

  For a multi-functional pin (a pin that has functions specified in the Functions filed in the Pins mode of the Properties panel), click in the pin's cell in the Name column and select the pin function in the drop-down that appears. The selected function will be shown as the pin name on the schematic sheet.

• Show Full/Show Short - in Show Full the full extended pin names of all listed pins are displayed; in Show Short mode, the current pin name is displayed.

• – when the button is enabled (the closed lock icon), the pins of the component are prevented from being edited. Only the component itself can be edited. If you wish to edit a pin by selecting it in the design space, disable this option.
• – use this button to toggle the visibility of the component's pin on the schematic sheet. 
• Add – click to add a pin. Click  to delete a selected entry from the table. Click to open the Component Pin Editor dialog in which you can view all pins for either the component in the active schematic library document or a placed component (or part thereof) in the schematic editor.

Generic Components

Placing a Generic Component from the Components panel

When Altium Designer is connected to a Workspace, the available Generic Components can be accessed from the Components panel where they are exposed when the All option is selected in the Categories pane – or from the top drop-down menu when the panel is in its compact mode. Click on the button within a Generic Component tile to attach the component to the cursor for placement in the active schematic. Selecting the tile itself will open that component type category in the Components panel.

Generic Component Properties

General

• Designator – enter the designator. Toggle the eye icon to show/hide the designator. Click the lock icon to lock/unlock the designator.
• Comment – enter the name. Toggle the eye icon to show/hide the name.
• Description – the generic component/part description.
  • Replace – select the Replace button when a design has progressed to the point where a Generic Component can be replaced with a specific physical component using the Replace Component dialog.

Location

• (X/Y)
  • X (first field) – the current X (horizontal) coordinate of the reference point of the object, relative to the current design space origin. Edit to change the X position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default.
  • Y (second field) – The current Y (vertical) coordinate of the reference point of the object, relative to the current origin. Edit to change the Y position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default.
• Rotation – use the drop-down to select the rotation.

Parameters

• Grid – lists the Name and Value of the parameters associated with the currently selected component. Use the lock icon to lock/unlock a listed parameter. Parameter values can be manually entered, or selected from a drop-down menu list that offers values sourced from all the available components of that type. You may the eye icon to show/hide the parameter.
• Font – click on the displayed font to change the font style.
• Other – click to open a drop-down to change additional options:
  • Show Parameter Name – enable to show the parameter name.
  • Allow Synchronization with Database – enable to synchronize with the database. This option is used to control if the comment can be updated. By default, these options are enabled to always allow synchronization with the source library/database. You may disable this option to prevent that comment from being included in an update process.
  • (X/Y) – enter the X and Y coordinates.
  • Rotation – use the drop-down to select the rotation.
  • Autoposition – check to enable auto-positioning, meaning that the parameter is positioned automatically every time the associated component is rotated. Disable this option to keep the parameter position to the associated component when it is rotated.

The Designator uniquely identifies each component in the design.

Summary

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 in all the schematic sheets in the project.

Availability and Placement

The designator is automatically placed when the parent component part object is placed. It is not a design object that you can directly place.

Graphical Editing

The designator string can be edited graphically using what is known as in-place editing. To edit a designator string in place, select the designator by dragging your cursor around it, then hit enter.

An example of in-place editing

Once editing is complete, press Enter or click away from the string to exit in-place editing mode.

Non-Graphical Editing

There are two aspects to consider in relation to editing the designator: editing the value of the designator and editing the display properties of the designator. 

The designator (and comment) strings can be displayed in the schematic library editor then doubled-clicked on to edit the properties. The  icon associated with the field in the Properties panel is used to show or hide the designator.

Editing the Designator Value in the Schematic Editor

The designator can be defined in the schematic editor as the component is being placed or after the component has been placed on a schematic sheet in the Properties panel.

• To edit the designator during component placement, press the Tab key while the component is floating on the cursor. The Properties panel will open; enter the required designator string. Click the design space pause button overlay ( ) to resume placement.
• Continue to place components or press Esc to terminate placement.
• Press the Spacebar to rotate the arc counterclockwise or Shift+Spacebar for clockwise rotation. The action can also be performed while dragging the object. Rotation is in increments of 90°.
• To edit the designator after placement, double-click on the placed component to open the Properties panel where the designator can be edited. 

Editing the Designator Display Properties 

The appearance of the designator string, which includes the font type, size, and color, can be configured on the Schematic - Defaults page of the Preferences dialog. These settings will apply unless overridden by settings defined in the component symbol in the Schematic Library Editor.

​

Fixing the Location of the Designator String

The default behavior of the Designator is to auto-position it as a component is rotated during placement. If this behavior is not required, turn off the Autoposition option in the Preferences dialog (refer to the previous image) either during symbol creation or after the component has been placed on a schematic sheet. Note that doing this sets this parameter to be classified as a manual parameter (meaning manually positioned parameter). Manual parameters are identified by a dot on the lower left corner of their selection box.

Notes

• The Schematic Editor includes a simple auto-increment feature for the designator that can be used during the placement of multiple instances of the same part. To use this, press Tab while the first component is floating on the cursor and enter a suitable designator, for example R1. Subsequent components will then be designated R2, R3, etc. Note that when you switch to placing a different component type you must again press Tab and enter a suitable designator prefix.
• When placing multi-part components and the initial designator is assigned as just described, a part suffix will automatically be assigned, for example, U3A, U3B, etc. If the initial designator is not assigned, all parts will have the same suffix. This is resolved by the Schematic Editor's Annotation command. The part suffix can be alpha or numeric. Use the Alpha Numeric Suffix option on the Schematic - General page of the Preferences dialog to configure.

Location

• (X/Y) 
  • X (first field) - the current X (horizontal) coordinate of the reference point of the object, relative to the current workspace origin. Edit to change the X position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
  • Y (second field) - The current Y (vertical) coordinate of the reference point of the object, relative to the current origin. Edit to change the Y position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
• Rotation - use the drop-down to select the rotation. 

Properties

• Object  - displays the associated object.
• Name -  enable this field by clicking the visibility icon () to add the prefix "Designator:" to the designator value itself. Doing so visually distinguishes and confirms that the text value is a designator within the schematic document.
• Value - displays the designator name itself. Toggle the eye icon to show/hide the value.
  • Autoposition -  check to enable auto-positioning, meaning that the text will remain in the chosen position as the component is moved and rotated.
  • Lock Parameter - check to lock the parameter, which prevents the value from being edited from the Properties panel or schematic document.
  • Allow Synchronization with Database - enable to synchronize with the database. This option is used to control if the comment can be updated. By default, these options are enabled to always allow synchronization with the source library/database. You may disable this option to prevent that comment from being included in an update process.
• Font - use the controls to select the font, font size, font color, and add any desired special characteristics to the font, such as bold, italics, and underlines.
• Justification - click the arrows to configure the justification of the text or circle to center.  
• Override Library Primitive (Preferences dialog only) - enable this checkbox to override the primitive settings defined for the designator object in a library. Therefore, when a component is placed, it will adopt the primitive settings you have defined in the Preferences dialog, rather than those that have been defined for the component in the library.

A Comment allows for displaying additional information for a component.

Summary

The Comment field is a child parameter object of a schematic component (part). It is used for displaying additional information for a component in a schematic sheet of the project.

Availability and Placement

The Comment is configured when the parent component part object is placed. It is not a design object that you can directly place.

Graphical Editing

The Comment can be edited graphically using what is known as in-place editing. To edit a Comment in place, click once to select, pause for a second, then click a second time to enter edit mode.

Click once to select the string.

Once editing is complete, press Enter or click away from the string to exit in-place editing mode.

Non-Graphical Editing

There are two aspects to consider in relation to editing the Comment: editing the value of the Comment and editing the display properties of the Comment. 

Editing the Comment in the Schematic Editor

The Comment can be defined in the schematic editor as the component is being placed or after the component has been placed on a schematic sheet in the Comment field of the Properties panel.

• To edit the comment during component placement, press the Tab key while the component is floating on the cursor. The Properties panel will open; enter the required Comment. Click the design space pause button overlay ( ) to resume component placement.
• Continue to place components or press Esc to terminate placement.
• To edit the Comment after placement, double-click on the placed component to open the Properties panel where the Comment can be edited. 

Editing the Comment Display Properties 

The appearance of comments, which includes the font type, size, and color, can be configured on the Schematic - Defaults page of the Preferences dialog.

Fixing the Location of the Comment

The default behavior of the Comment is to auto-position it as a component is rotated during placement. If this behavior is not required, disable the Autoposition option in the Preferences dialog (refer to the previous image) either during symbol creation or after the component has been placed on a schematic sheet. Note that doing this sets this parameter to be classified as a manual parameter (meaning manually positioned parameter). Manual parameters are identified by a dot on the lower-left corner of their selection box.

Location

• (X/Y)
  • X (first field) - the current X (horizontal) coordinate of the reference point of the object, relative to the current design spaceorigin. Edit to change the X position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
  • Y (second field) - The current Y (vertical) coordinate of the reference point of the object, relative to the current origin. Edit to change the Y position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
• Rotation - use the drop-down to select the rotation. Choices are: 0 Degrees, 90 Degrees, 180 Degrees, and 270 Degrees.

Properties

• Component - displays the name of the associated component. Click the Component link to open the Part Properties panel, where you may edit component options, as well as the comment itself, which will be defined in the Comment field of that panel.
• Name - enable this field by clicking the visibility icon () to add the prefix "Comment:" to the comment value itself. Doing so visually distinguishes and confirms that the text value is a comment within the schematic document.
• Value - displays the comment name itself. Toggle the () to show/hide the value.
  • Autoposition -  check to enable auto-positioning, meaning that the text will remain in the chosen position as the component is moved and rotated.
  • Lock Parameter - check to lock the parameter, which prevents the value from being edited from the Properties panel or schematic document.
  • Allow Synchronization with Database -  enable to synchronize with the database. This option is used to control if the comment can be updated. By default, this option is enabled to always allow synchronization with the source library/database. You may disable this option to prevent the comment from being included in an update process.
• Font - use the controls to select the font, font size, font color, and add any desired special characteristics to the font, such as bold, italics, and underlines.
• Justification - click the arrows to configure the justification of the text or circle to center.  
• Override Library Primitive (Preferences dialog only) - enable this checkbox to override the primitive settings defined for the comment object in a library. Therefore, when a component is placed, it will adopt the primitive settings you have defined in the Preferences dialog, rather than those that have been defined for the component in the library.

Parameters are used for objects (a component is shown in the above image), documents and projects to add detailed information to the design.

Summary

Parameters are general purpose text strings that are child objects of a parent object. They identify and add additional information to that parent object and are accessed directly in the Properties panel when selected in a schematic sheet.

Schematic components, for example, make extensive use of parameters. They are used to define the Sheet Name and the Comment, as well as the general purpose data strings that can be added to a component to fully define it. General purpose (User) component parameters can be used for a variety of functions including; component details and ratings, supplier information, library references, and datasheet links.

Parameters also can be defined at the schematic sheet (document) and project levels. Document-level parameters are used for defining fields such as the document title and number, while project-level parameters are ideal for defining fields such as the designer or the project name.

Availability

Parameters are added or automatically included as a property of the parent object and are not placed independently like a Text String. The types of available parameters can be broadly grouped as System and User parameters, where the latter is manually added.

Identifier and System Parameters

A range of key system parameters is automatically included with objects placed in a schematic. These provide the base object information that is used by the system to distinguish the parent object's name, type and data source.

The inherent system parameters for objects include, but are not limited to, the Comment, Description and Design Item ID (Library Reference) properties.

Object system parameters are accessible in the General section of the Properties panel (under the General tab) when a parent object is selected. When visible and selected in the design space, an individual parameter is accessible via the associated mode of the Properties panel as outlined below.

   Left: Component system parameters in the Properties panel. Right: An individual system parameter in the Properties panel.

User Parameters

Parameters are added as a property of the parent object and are not placed independently like a Text String. Parameters can be added to any of the following design objects:

• Component – add user-defined parameters in the Parameters tab of the Properties panel when a Component (Part) object is selected, or during component definition in the Schematic Library editor. System parameters such as Designator and Comment are always present for a Component object, as outline above. The Properties panel is accessed by double-clicking on an object, or by right-clicking on an object and choosing Properties from the context menu. Select an object in the design space if the Properties panel is already active.
• Part – in the Parameters region of the Properties panel when a Part object is selected.
• Pin - on the Parameters tab of the Properties panel when a Pin object is selected within a .SchLib file.
• Port – on the Parameters tab of the Properties panel when a Port object is selected.
• Sheet Symbol – on the Parameters tab of the Properties panel when a Sheet Symbol object is selected.
• Document – on the Parameters tab of the Properties panel when in Document Options mode (deselect all schematic objects or click in free space on the document sheet). A number of default parameters are automatically included in a new schematic sheet, as determined by the applied/default sheet template.
• Project - in the Project Options dialog (Project » Project Options). Project-level parameters are listed and added on the Parameters tab of the dialog.

While placing an object (Component, Sheet Symbol, etc.,), press Tab to pause the placement and access the parent object mode of the Properties panel from where parameters can be added or modified on the fly. Click the design space pause button overlay ( ) to resume placement.

User parameters are available under the Parameters tab of the Properties panel, or modal dialog,  when the parent object is selected – parameters can be both added and edited. The exceptions are Project parameters (via the Project Options dialog) and Component Pin parameters (via the Pin Properties, or the modal view of the Pin dialog). When visible and selected in the design space, an individual parameter is accessible via the associated mode of the Properties panel, or modal dialog, as outlined below.

Left: Component user parameters in the Properties panel (Parameters tab). Right: An individual system parameter in the Properties panel.

Graphical Editing

Visible parameter strings can be edited graphically, directly in the design space.

Click and drag a parameter to reposition it. To edit the parameter string in place:

1. Drag your mouse cursor around the parameter object while keeping the mouse button pushed down.
2. Once selected, the object will be highlighted by a green border.
3. Select Enter to begin editing the text.
4. Once editing is complete, press Enter again or click away from the string to exit in-place editing mode.

A parameter string can be selected and edited directly in the design space. (Right) Select the entire string to type over it.

Parameters that are visible and selectable in the design space may be dragged to a new location and rotated during the process. Click and drag the parameter string, use the Spacebar and Shift+Spacebar keys to rotate it in 90° steps, and then click to confirm its new position/orientation.

See Parameter String Positioning below for information on component parameter Autopositioning and related Properties panel options.

Locked Parameters

A parameter that is the child of a Component Part can be locked, where its Name and Value strings are made uneditable. This can be done by:

• toggling the Lock icon () associated with its entry under the Parameters tab in the Properties panel or modal dialog for its parent object, or
• checking the Lock Parameter option in the Properties panel when the parameter is directly selected in the design space.

Once locked, the parameter string cannot be edited in the Properties panel, modal dialog (under the Parameters tab for the parent object), or in the design space using in-place editing.

Component Parameters

Component parameters, the most obvious and frequently used Schematic parameters, include additional sets of dedicated parameters and features that expand the ability to define component objects.  

Defining Parameters in the Schematic Library

Prior to placement in a schematic, the child parameters of a parent component object can be defined in the component library source. Using the Properties panel in the same manner as when working with parameters in the Schematic Editor, the panel is used to edit and add parameters to a component entry in the Schematic Library Editor.

With a schematic component library document open, select a component entry in the SCH Library panel (View » Panels » SCH Library) to access its parameter properties in the Properties panel.

Access the properties of a library component by selecting its entry in the SCH Library panel.

A library component's Designator and Comment are not visible in the Schematic Library editor design space by default but can be enabled by checking the Show Comment/Designator option in the Library Options mode of the Properties panel (Tools » Document Options) – available when no objects are selected in the design space.

Parameters that are owned by a library component are defined and edited by the same process applied to placed schematic components. The Tab key may be used to create or edit parameters on the fly, while an object is being placed in the editor design space. Parameters are accessed via the Properties panel or modal dialog, where the core system parameters are available under the panel's General tab, and user parameters are added/edited under the panel's Parameters drop-down.

The Designator Parameter

In the Library Editor, a component Designator parameter is typically given a suitable prefix followed by a question mark. When the component is placed in a schematic from the library, the question mark is detected by the Schematic Editor's Annotation tool and replaced with a suitable numeric suffix during project annotation.

The Schematic Editor also includes a simple auto-increment feature for the designator that can be used during the placement of multiple instances of the same part. To use this, press Tab while the first component is floating on the cursor to pause the placement, and then enter a suitable designator in the Properties panel; for example R1. Subsequent components will then be designated R2, R3, etc. 

When placing multi-part components and the initial designator is assigned in this way, a part suffix will automatically be added, for example U3A, U3B, etc. If the initial designator is not assigned, all parts will have the same suffix – this can be resolved by the Schematic Editor's Annotation feature. The part suffix can be alpha or numeric, as specified by the Alpha Numeric Suffix option in the Schematic - General page of the Preferences dialog.

Parameter String Positioning

The default behavior of a component parameter string is to autoposition it (maintain orientation) when a component is rotated during or after placement. If this behavior is not required, turn off the Autoposition option for that component parameter entry under the Parameters tab in the Properties panel – select the parameter in the list and click the Other link for access to the option.

Click and drag a visible parameter to manually reposition that parameter on the schematic – the standard orientation shortcut keys (Spacebar, Shift+Spacebar) will apply. If the Autoposition option is disabled for that parameter and the Mark Manual Parameters option is enabled in the Schematic - Graphical Editing page of the Preferences dialog, manually-moved parameters will be identified by a dot on the lower left corner of their selection box.

Special Purpose Component Parameters

Special purpose component parameters are available for linking to related URL targets or file-based documentation. For a selected component, these are added in the Links section of the Properties panel, or under the Parameters tab for dedicated Help links that are activated via the F1 key.

Link Parameters

The Links feature enables the definition and presentation of named links to any number of reference URLs or documents.

To add a reference link for a component, select it in the design space, click the drop-down in the Links section of the Properties panel, and then enter the link Name and its  Value (target URL or file path). The link is then accessible by right-clicking on the component in the design space and selecting the link Name from the References sub-menu.

The component links, as presented in the panel and design space, are internally based on Name/Value pairs in the format of ComponentLinknDescription/ComponentLinknURL (where n is number of the link in the list, based on the order of creation). See the Parameter Table Editor entry for that component to see more detail.

The HelpURL Parameter

Not unlike the Link parameter, the HelpURL parameter allows the definition of a link from a component to an external document, such as a PDF, or web page URL. When added as a component parameter, this link is activated when the F1 key is pressed over the component on the schematic sheet, or when that component is selected in the Libraries panel. Note that this action will override the normal F1 key feature, which links to the relevant page in the Altium online documentation.

The Help link is added as a user parameter under the Parameters tab of Properties panel, when a component is selected in the design space. Click the drop-down button to create a new parameter in the list, enter HelpURL as the parameter Name and then the target path/URL as the parameter Value.

When specifying the value for the parameter, this can be a URL, an absolute path to a document or just the document name. When F1 is pressed with the cursor hovering over the placed component object, or the References » Help option is used from the right-click menu, a search for the Help reference is conducted as follows:

• If a path is specified, this location is searched first.
• If the document cannot be found at this location, or if no path is specified, the \Help folder of the software installation is searched.
• If the target is a URL, the web page will be opened in the software's internal browser or an external browser, depending on the state of the Open internet links in external Web browser option on the System - View page of the Preferences dialog.

Indirection - A Parameter as a String Value

Most component parameters can be displayed on a schematic sheet by checking their Visible option (where available) in the Properties panel (). Identifier and system parameters are available under the panel’s General tab, and user parameters are accessed under the panel’s Parameters tab.

Other parameters, however, such as Document and Project parameters, cannot be directly displayed on the schematic sheet but may be inserted in a standard Text object using a technique known as String Indirection. Indirection is where the Value entry for a string object is the name of an available parameter (such as a Document or Project parameter) preceded by an equals sign – for example; =Title.

The software automatically detects such strings and checks for an available parameter Name that matches the Value entry of the placed Text object. The example of Title is found as a document parameter, causing the Text string to interpret and display the Title parameter Value – for example; MyDocument. A parameter Name may be indirected to a selected text string Value by in-place editing (typing =Title into it), or as a more informative approach, by using the Text drop-down menu in the Properties panel to select from the available parameter strings.

Special Strings

Parameter strings that are available as indirected strings (see above) are known as Special Strings. The Value presented by these strings is actively inferred from templates or system and source data, so for example the special string =Time will detect and show the current system time, and =DocumentName will show the current schematic document file name (say, MySchematic.SchDoc).

There is a large number of predefined special strings available, which are listed below. Any user-defined document or project parameter can also be thought of as a special string and be indirected to a Text String on the schematic sheet.

Parameters have a hierarchy, which means you can create a parameter with the same name at different levels of the project, each having different values. For a component parameter, Altium Designer resolves this in the following way:

1. Component parameter (highest priority)
2. Variant
3. Schematic document
4. Sheet Symbol (to see the value of the parameter of the sheet symbol above, select a compiled tab at the bottom of the design space)
5. Project

Schematic Predefined Special Strings

The following are the predefined special strings available for use on a schematic document. The majority of these link to default parameter information defined for the active document on the Parameters tab of the Properties panel, when in Document Options mode (no objects selected). Any special strings available at a project level can be viewed/added on the Parameters tab of the Project Options dialog.

• =Address1 – displays the value specified for the default document-level parameter Address1.
• =Address2 – displays the value specified for the default document-level parameter Address2.
• =Address3 – displays the value specified for the default document-level parameter Address3.
• =Address4 – displays the value specified for the default document-level parameter Address4.
• =Application_BuildNumber – displays the version and build for the current Altium software installation.
• =ApprovedBy – displays the value specified for the default document-level parameter ApprovedBy.
• =Author – displays the value specified for the default document-level parameter Author.
• =CheckedBy – displays the value specified for the default document-level parameter CheckedBy.
• =CompanyName – displays the value specified for the default document-level parameter CompanyName.
• =ConfigurationParameters - displays the value specified for the default document-level parameter ConfirguationParameters.
• =CurrentDate – the current date, automatically calculated from the user's system settings and in the format dd/mm/yyyy, updated upon editing the schematic or on refresh/redraw. Example: 10/12/2017.
• =CurrentTime – the current time, automatically calculated from the user's system settings and in the format h:mm:ss AM/PM, updated upon editing the schematic or on refresh/redraw. Example: 2:39:47 PM.
• =Date – used to display static date information. Displays the value specified for the default document-level parameter Date. Unlike the =CurrentDate special string, which is automatically calculated and presented in a set format, the user can enter static date information in any format they prefer.
• =DocumentFullPathAndName – used to display the full path and name of the document into which the string is placed. Example: C:\MyTestDesign\PSU.SchDoc.
• =DocumentName – used to display the schematic's file name only (without the file path). Example: PSU.SchDoc.
• =DocumentNumber – displays the value specified for the default document-level parameter DocumentNumber. The source parameter can also be updated through the Sheet Numbering for Project dialog when using the Tools » Annotation » Number Schematic Sheets command.
• =DrawnBy – displays the value specified for the default document-level parameter DrawnBy.
• =Engineer – displays the value specified for the default document-level parameter Engineer.
• =ImagePath – displays the value specified for the default document-level parameter ImagePath.
• =IsUserConfigurable - user can configure.
• =Item – the Item that the generated data relates to (e.g., D-810-2000). The data will be used to build that Item.
• =ItemAndRevision – the Item and specific revision of that Item to which the generated data relates in the format <Item ID>-<Revision ID> (e.g. D-810-2000-01.A.1). The data will be used to build that specific revision of that particular Item.
• =ItemRevision – the specific revision of the Item to which the generated data relates (e.g., 01.A.1). The data is stored in that Item Revision within the target server.
• =ItemRevisionBase – the Base Level portion of an Item Revision's naming scheme (e.g., 1).
• =ItemRevisionLeve1 – the Level 1 portion of an Item Revision's naming scheme (e.g., A).
• =ItemRevisionLeve1AndBase – the Level 1 and Base Level portions of an Item Revision's naming scheme (e.g., A.1).
• =ItemRevisionLevel2 – the Level 2 portion of an Item Revision's naming scheme (e.g., 01).
• =ItemRevisionLevel2AndLevel1 – the Level 2 and Level 1 portions of an Item Revision's naming scheme (e.g., 01.A).
• =LibraryName - displays the actual name of the schematic library file. (e.g., SpiritLevel_2E.SchLib)
• =ModifiedDate – the modified date stamp of the schematic is automatically populated. Example: 10/12/2015.
• =Organization – displays the value specified for the default document-level parameter Organization.
• =PCBConfigurationName – the name of the data set from which the output has been generated as defined in the Release view (Project Releaser).
• =Project – displays the name of the project (excluding extension). 
• =ProjectName – displays the actual name of the project (including extension). For example, for a project with filename MyPCB.PrjPcb, this special string will display MyPCB.PrjPcb.
• =ProjectRev - displays the project revision.
• =Revision – displays the value specified for the default document-level parameter Revision.
• =SheetNumber – the sheet number of the current schematic. This value is calculated when using the Tools » Annotation » Number Schematic Sheets command. The assigned sheet number, in the Sheet Numbering for Project dialog, will be entered into the value for the default document-level parameter SheetNumber. The special string when used on the Editor tab view of the schematic sheet will source its information from here.
• =SheetTotal – the sheet total for the project. This value is calculated when using the Tools » Number Schematic Sheets command. The sheet total, in the Sheet Numbering for Project dialog, will be entered into the value for the default document-level parameter SheetTotal. The special string when used on the Editor tab view of the schematic sheet will source its information from here.
• =Time – used to display static time information. Displays the value specified for the default document-level parameter Time. Unlike the =CurrentTime special string, which is automatically calculated and presented in a set format, the user can enter static time information in any format.
• =Title – displays the value specified for the default document-level parameter Title.
• =VariantName - displays the variant from which output has been generated. This follows the entry for the current variant. If the base design is used to generate the output, the value will simply be [No Variations].
• =VersionControl_ProjFolderRevNumber – the current revision number of the Project, which is incremented whenever a full commit of the project (i.e. including the project file) is performed. Version control must be used for this string to contain any information.
• =VersionControl_RevNumber – the current revision number of the document. Version control must be used for this string to contain any information.

Special Strings for Use with Component Parameters

Several additional special strings (or special interpretations of existing ones) are available when defining component parameters. In each case, the special string is entered as the value for a parameter.

• =CurrentFootprint – displays the name of the currently assigned footprint for the component as defined in the Models region of the Properties panel (General tab).
• =Comment – displays the value appearing in the component's Comment field as defined in the Properties region of the Properties panel (General tab).
• =Description – displays the value appearing in the component's Description field as defined in the Properties region of the Properties panel (General tab).
• =[ParameterName] – displays the value defined for a specified component parameter. Enter the actual name of a component parameter as the special string name. For example, for a component parameter named PowerRating, enter =PowerRating. This approach can be used to display a component parameter such as Description by creating a user parameter (under the Parameters tab of the Properties panel) with a value of =Description, and then enabling that parameter's visibility in the schematic.

Location

• (X/Y) 
  • X (first field) - the current X (horizontal) coordinate of the reference point of the object, relative to the current design space origin. Edit to change the X position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
  • Y (second field) - The current Y (vertical) coordinate of the reference point of the object, relative to the current origin. Edit to change the Y position of the object. The value can be entered in either metric or imperial; include the units when entering a value whose units are not the current default. 
• Rotation - use the drop-down to select the rotation.

Properties

• Object type - displays the type of object (Component, Sheet Symbol, etc.,) and parameter type.
• Name - the name of the parameter.
• Value - the value of the parameter. Toggle ​ to show/hide the value.
• Autoposition - check to enable auto-positioning, meaning that the text will remain in the chosen position as the component is moved and rotated.
• Lock Parameter (Preferences dialog only) - enable this option to prevent editing of the parameter's value, either graphically in the design space
• Allow Synchronization with Database (Preferences dialog only) - enable to synchronize with the database. This option is used to control if the comment can be updated. By default, these options are enabled to always allow synchronization with the source library/database. You may disable this option to prevent that comment from being included in an update process.
• Font - use the controls to select the font, font size, font color, and add any desired special characteristics to the font, such as bold, italics, and underlines.
• Justification - click the arrows to configure the justification of the text.