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DACS: System Description
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System Description

The user shall be able to control the mixing features of the DACS mixer module via familiar slide potentiometers (faders). The values of these potentiometers shall be digitized with an 8-bit A/D converter, and processed appropriately via the internal microcontroller. Because ``flying faders'' will not be used on this board due to cost, each channel shall have two LED indicators associated with it to aid in adjusting channel values. The ``active'' indicator shall light if a particular channel is active in the current mixer/matrix mode. The ``grab'' indicator, used when editing mix settings, shall light green when the fader has been moved from the current setting, and red when the old value has been ``grabbed''. The user shall have control over the channel assignment features of the DACS mixer via a set of pushbutton switches and associated LEDs. The active output channels for a given input channel shall be toggled with these switches. The input channel that is being controlled shall be selectable via two pushbutton switches. An LED display shall provide visual indication of the active channel number. The user shall be able to control the transports of various physical or virtual audio devices. An interface shall be provided to allow the user to select which device to work with, via a pair of pushbutton switches. Visual indication of the current transport shall be provided via a 16 character alphanumeric LCD. The transport controls shall allow the track index and time index to be adjusted. Track index shall be adjusted via a pair of pushbutton switches. Time index shall be adjusted via a detented rotary encoder wheel. ``Play,'' ``Cue,'' and ``Stop'' functions shall also be available to the user, via pushbutton switches with LED indicators for visual reference. The user shall be able to execute a series of pre-programmed cues from the board. These cues may include, but are not limited to, mixer events, transport events, MIDI events, etc. In addition, rudimentary cue stack editing shall be allowed from the board. Cue information shall be presented to the user via a 40x2 LCD. Three buttons shall be used to navigate and execute the cue stack. The unit shall incorperate an appropriate internal power supply. External connection to this supply shall be made via a standard IEC power connector at the rear of the unit. This power entry unit shall be of the type that filters EMI and RFI interference. It shall be appropriately fused and switchable via a rocker switch. The board's microcontroller shall communicated with the rest of the DACS via an RS485 4-wire serial interface. This interface shall be presented as a 5-pin male XLR connector, and shall be wired per the DMX512 lighting control specification. This connector was chosen due to its robustness. The adherence to the DMX512 specification merely eliminates any potential equipment malfunction due to accidental interconnection, as DMX512 uses the same connectors, and will often be present in places this mixer will be used. The serial communication shall take place at 9600 baud. The unit shall be referred to as DACS Model 112 - System Control Board.
next up previous contents
Next: Specification Sheet Up: Control Board Previous: Control Board   Contents
Steve Richardson 2000-07-06
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