Compact FLASH III Digital Audio System
Copyright©1992-2010 by ACS, Sarasota, Florida
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ALL RIGHTS RESERVED
Analog Input Wiring
On the optional DMX Module, analog signals with a voltage range of 0 → 12VDC may be connected.
The input impedance is approximately 6000 ohms. Linear potentiometers with a 1K @ 250mW value may be
connected across the VEE and GROUND terminals with the wipers connected to the analog inputs. The
analog conversions are ratio-metric to the scaled VEE value – not absolute. The conversion result is 12 volts
divided by 8 bits or about 0.047 volts per step.
The following diagram is representative of one analog input:
ANALOGx
GROUND
+12v
5.1K
ohm
1K
ohm
1.0uF
VEE
350mA
DMX Wiring
The CFSound-III may be wired into the DMX network in one of two ways. As a DMX controller, the
CFSound-III is connected at the beginning of the network‟s daisy chain of devices. As a DMX device, the
CFSound-III may be connected anywhere along the network‟s daisy chain.
DMX devices such as lights are connected in a daisy-chain fashion: from the controller to light #1, to
light #2, to light #3 and so forth. According to the standard, a DMX-512 controller can only drive up to 32
loads (e.g., one light controller = one load). But improvements in technology have reduced the load a single
light puts on the circuit, so you may be able to drive as many as 128 lights (each one being 1/4 load) from a
single controller such as the CFSound-III DMX I/O module. To control additional loads (lights), a DMX
splitter is required.
Here‟s a block diagram showing how the CFSound would be connected as a DMX Controller (Master):
CFSound-III
DMX I/O
IsMaster=TRUE
MALE FEMALE
DMX
Device
DMX
Device
Terminator
CFSound-III as DMX Controller (Master)
The final device in the daisy-chain must be terminated. Terminating plugs contain a 120 ohm resistor
soldered across pins 2 and 3. The terminator functions by absorbing signal power which would otherwise be
reflected back into the cable and degrade the data.
Here‟s a block diagram showing how the CFSound would be connected as a DMX Device (Slave):
