Altium Designer Documentation

WorkspaceManager_Err-Unsupportedmulti-channelalternateitemUnsupported Multi-channel Alternate Item_AD

Created: August 3, 2021 | Updated: August 3, 2021
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Parent category: Violations Associated with Others

Default report mode:


This violation occurs when, for a given variant of a multi-channel design, different Alternate Parts have been used for a component across channels.

Alternate Parts are not fully supported for multi-channel designs, and therefore, using different Alternate Parts across different channels for a design component can lead to inconsistent data.


If compiler errors and warnings are enabled for display on the schematic (enabled on the Schematic - Compiler page of the Preferences dialog), an offending object will display a colored squiggle beneath it. Hovering over the object will display a pop-up hint that summarizes the violation. A notification is also displayed in the Messages panel in the following format:

There are alternate items for multi-channel item "Component <ComponentLogicalDesignator> <ComponentName>" in variant "<VariantName>". Please, check your variant configuration. Alternate parts aren't fully supported in multi-channel designs and can lead to inconsistent data


  • ComponentLogicalDesignator is the logical designator for the affected component (the designator as displayed on the Editor tab view of the relevant schematic document on which the component in question resides).
  • ComponentName is the name of the component in violation.
  • VariantName is the name of the design variant for which Alternate Part choices have been chosen across channels for the component in violation.

Recommendation for Resolution

Use the Details region of the Messages panel to cross-probe to the component in question. To resolve this type of violation, either choose the same Alternate Part for all affected channels or set the component to Fitted or Not Fitted for a channel so that there are no longer different Alternate Parts in use. To do so:

  1. Make the relevant variant the current variant from the Variants folder for the parent project in the Projects panel. From the Editor tab for the document, right-click on the part in violation and choose Part Actions » Variants. This opens the Variant Management dialog with only the offending component presented (across all channels).
  2. For each offending channel, use the Component Variation field to access the Edit Component Variation dialog.
  3. With the Alternate Part option still selected, use the other options in the dialog to browse to and choose the same (required) part already used in another channel. Alternatively, choose to make the component Fitted or Not Fitted for that particular channel.
  4. OK out of the dialogs and recompile the design project. The violation should now have been resolved and no longer appear (unless there are multiple components with this issue, in which case, repeat the previous steps).


  • Object hints will only appear provided the Enable Connectivity Insight option is enabled on the System - Design Insight page of the Preferences dialog. Use the controls associated with the Object Hints entry in the Connectivity Insight Options region of the page to determine the launch style for such hints (Mouse Hover and/or Alt+Double Click). 


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