1. Firstly, the Component must have the logic names defined within it. If they aren't defined, then clearly they can't be shown in the Schematic.
  2. If they are defined but not displayed, try checking the display settings.
  3. Go to Colours from the View menu.
  4. Check that Pin Names is checked as on.
  5. Another small check is to ensure that the colour used for Pin Names is not the same as the background colour otherwise they will be invisible!
  6. For any individual Component in the Schematic, you can also make the login names visible/invisible by selecting the component and using Properties from the context menu.
  7. Under Properties, select Component. Select the Pin Name check box.