System CD employs resistance or transformer dimmers electro-mechanically driven through a clutch servo as described for System PR. The control console is provided with a memory device which stores and instantly recalls groups required for collective operation. This memory device and other exclusive facilities combine to provide te operator with an instrument capable of executing complex lighting changes in rapid succession in addition to precise presetting of dimmer levels.

1. Channel Selectors
   One to each channel. When put down the channel is selected to change but will not do so without one of the Master Controls.
2. Memory Preset Pushes
   Any of these 14 pushes pressed while the "Presetter" toe push is pressed will store the combination of Channel Selectors selected at that moment. Subsequent use of that push without "Presetter" will always cause the Channel Selectors to move instantly to the combination previously stored. A permanent "Cancel" push, which causes all Channel Selectors to spring off, aids selection by hand.
3. Dimmer Levers
   Two for each channel arranged in separate white and green rows. These Dimmer Levers can be preset for dimming changes involving intermediate intensity levels.
4. "Raise" Master Push
   Raises selected dimmers to full irrespective of the levels preset on the Dimmer Levers.
5. "Dim" Master Push
   Lowers selected dimmers to out irrespective of the levels preset on the Dimmer Levers. At "second touch" all dimmers fade to zero selected or not.
6. "White Preset" Master Push
   Moves selected dimmers to the levels preset on the white Dimmer Levers. At "second touch" all dimmers move to their preset levels.
7. "Green Preset" Master Push
   Moves selected dimmers to the levels preset on the green Dimmer Levers. At "second touch" all dimmers move to the preset levels.
8. Indicator Dial
   When a dimming change is initiated the progress and rate of change is shown on the Indicator Dial. If any Channel Selector is pressed to "second touch" the Indicator Dial shows the actual level of that dimmer.
9. Master Dimmer
   When added to a "Preset" master this applies a proportional reduction to the levels of selected dimmers.
10. "Blackout" Master Push
    All channels are automatically held "switched on" as the changes normally concern the dimmers. This push will blackout any selected channels. To restore to "on" the adjacent "All Trip" push is used.
    12. "Dead Blackout" All channels, selected or not, are switched off when the switch is down.
    Group Couplers
    Normally these are kept down but they can be put up to limit a change to a particular group (such as F.O.H. spots).

• "Remainder Dim" (cross-fade)
  This toe push is interlocked with the "Raise" and "Preset" masters and causes selected dimmers to change as described above but at the same time the remainder will fade out although their Dimmer Levers may be preset for future changes.
• "Speed Pedal"
  The Speed Pedal, which is balanced to stay at any position when the foot is removed, determines the speed of all dimming changes. Speed range 2 seconds to 45 seconds shown on indicator lamps. Slower speeds down to 30 minutes by means of Impulse Unit.
• "Individual" Toe Push
  If a Channel Selector is pressed to "second touch" at the same time as the "Individual" toe push then that dimmer only will come under immediate control.
• "Go" Master Push
  For Television requirements the channels are normally held "switched off" and selected channels are "switched on" in the same manner.