Dove Systems MTX-DE 48 User Manual

MTX-DE48 DMX DECODER

OWNER'S MANUAL

Rev. 5 - 7/03

Dove Lighting Systems, Inc.

3563 Sueldo Street Unit E

San Luis Obispo, Ca 93401

[phone] fax [phone]

[e-mail] / www.dovesystems.com

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INTRODUCTION

The MTX-DE decodes a multiplexed control signal into a DC voltage to drive standard analog dim­mers from any controller which is compatible with DMX-512 control. Each unit decodes 48 channels
and the starting channel may be set to be any dimmer, 1 to 512. The MTX-DE is factory set to start
on dimmer #1 and the control output voltage is set for 0 to +10V but can be adjusted up to +28.

SET UP AND CONNECTION

INPUT AND OUTPUT

The MTX-DE is usually located close to the dimmer packs it controls. The input and output connec­tions should be made before the decoder is plugged into power and energized. The circuit card is fac­tory set for 120VAC 50/60Hz power input; move the line voltage select jumper at J23 to set the line
voltage for 240V.

The DMX input is made at the male XLR connector. The signal loops
through on the female connector. Always use the loop through con­nectors to link equipment in series; do not split the DMX signal with­out one of the specialty interfaces for this purpose.

Connector pin designations are as shown in the right hand figure;
pins 4 and 5 are "passed through" with no connection made to these
pins.

There are 48 output positions, one for each dimming channel, and
two common terminals at J19 and J20. Positive voltage (i.e. 0 to
+10VDC) output connections are made on the PC terminal strip near
the middle of the circuit card. Some units may be equipped with neg­ative (i.e. 0 to -10VDC) outputs, in which case output connections
are made on the PC terminal strip to the rear of the circuit card. There must be a common wire to
each dimmer pack. A variety of rear panel output connectors are available as options.

It is possible to parallel an analog controller as a backup control on the outputs, but only if it has di­ode protection.

The MTX-DE is factory set for 0 to +10 volts output and to start on channel #1. Higher output volt­ages are possible: adjust R2 clockwise for voltage ranges up to 0 to +28V or 0 to -28V on negative
voltage units.

STARTING CHANNEL SELECT SWITCH

The starting channel is selected through a pushbutton switch on the front panel. Valid starting chan­nels range from 001 to 512. When the decoder controls the only dimmers in the system, the starting
channel should be set for 001. When there are two or more decoders in the system, the starting
channel may be set for 001, 049, 097, etc. Although channels may overlap, it is usually desirable to
arrange the system for one dimmer per channel. Dimming channels should not overlap with other
DMX equipment, including strobe lights, moving lights, and foggers.

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The starting channel select switch has a load test / self test function. Setting the switch to 600 turns

on all outputs at 20% of full scale (2 volts typical). Setting the thumbwheel to 601 turns output 1 on full

1 - Terminate DMX. Termination prevents possible data corruption problems due to signal reflections

When the input and output connections are made the unit may be energized by plugging into a power

at the first output terminal and run up the first channel on the controller. The output should range from

Try running the controller right next to the decoder, connecting the two with a short cable. If it works

then, but not with a long cable, there may be wiring errors, improper termination, or excessive common

The most common cause of trouble is a miswired connection. The pin configuration for the multiplex

connector is most important: the board will not work at all if any of the wires are not on the correct pin,

and the signal present LED will glow red only. There should be one control common connection per

dimmer pack. The common of the dimmer should not be tied to earth ground. There should be one

Try enabling the DMX termination option at switch S1-1. If there is more than one DMX device in the

with all other outputs off. 602 turns on output 2 while all others are off. This continues through 648.

OPTION SWITCH

The nine position DIP switch at S1 performs several functions:

back along the control cable. Termination should be set only at the last DMX device in the chain.
2 - Offset for 2 to 7.6 volt output. This requires readjustment of R2, the output level control, to yield
a 7.6 volt output.

3 - Nondim all outputs. Any DMX code of 128 or above yields full output.
4 - 48 channel offset. If this switch is on, 48 is added to the thumbwheel setting when it is set for a

DMX channel. This allows a 96 channel decoder to have a single channel select switch. When load
testing, if option switch 4 is on (48 channel offset), the unit instead responds to 649 to turn on the first
output through 696 to turn on the last output.

5 - Unassigned
6 - Unassigned
7 - Unassigned
8 - Unassigned
9 - Terminate floating DMX. This functions only with units with the opto isolated input option.

TESTING THE DECODER

source which can be turned on and off with the dimmer packs. The controller may now be energized
and the system tested. The LED on the front panel will glow red and then green upon power-up when
a valid DMX signal is present. It will glow red only without a valid signal. The decoder may be tested
with a voltmeter. Place the black probe at either common terminal at J19 or J20. Place the red probe

0V at off to full, usually 10V.

IN CASE OF TROUBLE

Try the load test function (see above). If it works, the decoder is functional.

mode voltage (requiring opto isolation).

control wire per dimmer channel. Verify these wires.

system, check that only the last device in the system has termination enabled.

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Flickering lamps across all channels may indicate the need for opto isolation. This device is an option

on the circuit board and can resolve ground loop problems along the control line. Please contact the

factory if this option is required.

tion of the problem, preferably from personnel who were on-site at the time. If at all possible, bring the

If the problem affects just a few channels, particularly channels that are close together, try swapping
IC chips to see if a problem follows a particular chip. Start at the output section, the part nearest the
output terminals.

CALLING THE FACTORY

Dove Systems hours are 8AM to 5PM Pacific time, Monday to Friday. Please have a specific descrip­telephone into the theatre and have the equipment at hand. Call [phone] or, after hours, send

an email to [e-mail] with a complete description of the problem.
When it is necessary to send the unit to the factory for prompt repair, please ship it freight prepaid,

with a note describing the specific complaint. Include the shipping address, a daytime telephone num­ber, and the date the unit is required back. It is helpful to call the factory beforehand for a Return Ma­terials Authorization (RMA) number. VERY IMPORTANT: PLEASE ENCLOSE A NOTE
DESCRIBING THE PROBLEM--EVEN IF YOU HAVE CONTACTED THE FACTORY BY PHONE.

Send to: Service Dept
Dove Systems
3563 Sueldo Street, Suite E
San Luis Obispo, California, 93401
Phone: [phone]

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LIMITED WARRANTY

The manufacturer agrees that its products shall be free from defects in material or workmanship

over a period of one year from date of shipment from the factory. Said warranty will not apply if

equipment is used under conditions of service for which it is not specifically intended. The

manufacturer is not responsible for damage to its apparatus through improper installation,

turer, and after receipt of shipping advice, buyer may return it directly to Dove Systems, San

Luis Obispo, CA, shipping prepaid. Such equipment will be replaced or put in proper operating

condition, free of all charges except transportation. The correction of any defects by repair or

replacement by the manufacturer shall constitute fulfillment of all obligations to the purchaser.

Manufacturer does not assume responsibility for unauthorized repairs to its apparatus, even

Manufacturer shall not be liable for any consequential damage in case of any failure to meet the

conditions of any warranty of shipping schedule, nor will claims for labor, loss of profits,

No other representation, guarantees or warranties, expressed or implied, are made by the

manufacturer in connections with the manufacture and sale of its equipment. This warranty is

physical damage, or poor operating practice.
If any device is found unsatisfactory under the warranty, the buyer should notify the manufac-

though defective.

repairs, or other expenses incidental to replacement be allowed.

non-transferable and applies to the original buyer only.
Copyright Dove Systems 1997

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