Display Logical Designators - choose this option to display the logical designators.Physical designators are unique, e.g., R1_CH1. For multi-channel designs, designator format is determined by the Designator Format field on the Multi-Channel tab of the Options for Project dialog. These are the designators displayed on the compiled tab views of the schematic source documents.
Display Physical Designators - choose this option to display the physical designators.Use this field to determine how designators are to be displayed. This would, of course, necessitate some other notation being added to the board to indicate the separate channels, such as a box being drawn around each channel on the component overlay. For example, C30_CIN1 would display as C30. As well as choosing a naming option that results in a short name, another option is to display just the original, logical component designation instead. It can be difficult to position the designator strings in a multi-channel design since they can end up being quite long. The measurement unit employed for the board can also be changed directly from the Ribbon menus using the and buttons in the Home | Grids and Units region. Default units are used to display any distance related information on screen or in reports. Click to select from either metric (mm) or imperial (mil) units.