Dove Systems MTX-DE 8 - Manual (Page 3)

3
Introduction
The MTX-DE8 is an 8 channel DMX decoder. It converts standard DMX-512 digital lighting
control signals to analog 0 to 10V control signal. The MTX-DE8 has 8 analog outputs. Each output
can drive one or more analog control inputs on dimmers or lighting fixtures (such as fluorescent fix-
tures with analog control inputs).
The main application of the MTX-DE8 is the control of fluorescent lighting fixtures. The MTX-
DE8 is mounted in the lighting grid near the fixtures to be controlled. A standard cable (available from
Dove Systems and other suppliers) with 50 ohm BNC connectors connects the fixture to the MTX-
DE8. Each BNC output on the MTX-DE8 corresponds to one DMX control channel. If several fixtures
are to always be driven with the same level, one BNC output can drive these several fixtures. If the
fixture has a pair of “loop through” BNC connectors, one fixture is connected to the MTX-DE8, and
the rest are “daisy-chained” from the first. If the fixture has only one BNC control input, a standard
BNC “Tee” connector can be used to provide the “loop through.”
The MTX-DE8 has a DMX input and a DMX output. The input is driven by the lighting control
console or a previous device in the DMX string. The DMX output drives the next device in the DMX
string. If no other device is to be driven, the terminate switch on the MTX-DE8 should be turned on to
properly terminate the DMX line.
Quick Start
Install the MTX-DE8 in the lighting grid near the fixtures it is to control. Connect a BNC cable
from an output to the fixture it is to control. If the output is to drive more than one fixture, use the “loop
through” BNC connector on the fixture (if available), or a BNC Tee connector. Connect a cable from
this connector to the next fixture. The analog control signal does not need to be terminated at the last
fixture.
Set the channel select switch to the DMX channel the first output is to represent. The second
output will be this channel +1. The last output will be this channel +7. For example, if the channel se-
lect switch is set to 001, the first output corresponds to DMX channel 1, while the last corresponds to
DMX channel 8. If the DMX switch is set to 008, the first output corresponds to DMX channel 8, while
the last output corresponds to DMX channel 16.
Connect the DMX input to the DMX source, whether that be the console or another device in
the DMX string. If this is the last device in the DMX string, turn on the DMX terminate switch on the
MTX-DE8.
Apply AC power to the MTX-DE48 and to the fixtures. When AC power is present, the LED on
the front of the MTX-DE8 lights. The LED is green if DMX is present and red if DMX is not present. As
the DMX control is varied, the brightness of the fixtures should vary appropriately.
Note that some fixtures do not dim all the way to off, no matter what the analog control voltage.
If this is the case, you will have to turn off the AC to the fixtures to turn them off. Fixtures designed to
work with the MTX-DE8 include circuitry to turn the fixture off when the control voltage approaches
zero.
The option switches on the front of the MTX-DE8 are reserved for future features.