This article explains the use of the Program and Preview Buses on the Ross Carbonite Video Switcher and terms used alongside it. Also covered, is the use of Program on the 'other' screens (Center and Scenic).
The two main rows of buttons that help select a source are referred to as the Program and Preview Rows or Busses.
The Program Bus - The top row of larger buttons is what is 'live' or 'on air'; the output goes directly to the side projectors no matter what.
We virtually assign the program output to be a source option in the Center and Scenic layers.
The Program feed can be obtained by holding the shift button and then pressing the BLK/PGM button directly to the left of it.
The best way to understand this method is to physically see the switch; however, here is an example to try and help explain.
During the sermon we have three screens in use: two outer side screens and the center motorized screen. The center screen output is independent of the Side screen output. Therefore, during the sermon, the center output is set to program so it shows the same content as the side screens. The side screen output will always be program. After the sermon, the switcher will need to be transitioned to ProPresenter. In order to transition all three screen at the same time, one would transition only the side screen layer, because the Center screen layer is set to pass through the same program signal.
For best practice, we don't recommend pressing the program bus buttons at any time. This is referred to as hot punching or cuts only. Best practice is to select the desired source on the Preview (Preset) row, then use the T bar to dissolve into the new source.
The Preview Bus - Labeled on the switcher as the Preset row is the lower row of large buttons. Preview is an easier way to remember the row, as it is the 'preview' of the source coming next with a transition.
For best practice, we recommend always previewing a source before taking it to program. This allows you to verify on the multiviewer what will be going to the screens. This is way to double check where you are going.
Here is very simple scenario to show you how we use the preview and program rows. During the 180 or stage time before the sermon, the switcher will be sending ProPresenter to the Program output. One would press the SAT button on the bottom row of buttons to 'Preview" the Satellite source to ensure it's working and ready to go next to the screens. At the correct time, as the Campus Pastor throws it to satellite, one would use the T Bar to transition the preview source to the program output to take satellite 'live' or to the screens.