If they are patched to DMX universese you can store DMX states in the snapshots. You do not need a console connected. You can alter DMX channels from the live mode and the console pane, or for access to all channels of a fixture you can go to the universes tab and switch the mode to "Fixtures". Then you can control the fixtures through the sliders.
Finally, if you connect a console then you can control them from the console instead of Capture controls, while you can still save snapshots of incoming DMX values. I hope it is all clear now.