Blizzard Lighting Memerizor RGB 3D Laser(Rev A) - Manual (Page 13)

Page 13
Mezmerizor™ Manual - Rev. A (c) 2013 Blizzard Lighting, LLC
No Light Output Check to ensure fixture is operating under correct mode, IE sound active/auto/
DMX/Etc., if applicable. Contact service for more information.
No Power Check fuse, AC cord and circuit for malfunction.
Blown Fuse Check AC cord and circuit for damage, verify that moving parts are not re-
stricted and that unit’s ventilation is not obstructed
No Response to
Audio
Verify that the fixture is in “Sound Active” mode.
Adjust Audio Sensitivity, If Applicable.
Fixture Not Respond-
ing / Responding
Erratically
Make sure all connectors are seated properly and securely.
Use Only DMX Cables.
Install a Terminator.
Check all cables for defects.
Reset fixture(s).
If your problem isn’t listed, or if problems persist,
please contact support: [email protected].
5. APPENDIX
A Quick Lesson On DMX
DMX (aka DMX-512) was created in 1986 by the United States Institute for Theatre Technology (USITT)
as a standardized method for connecting lighting consoles to lighting dimmer modules. It was revised in
1990 and again in 2000 to allow more flexibility. The Entertainment Services and Technology Association
(ESTA) has since assumed control over the DMX512 standard. It has also been approved and recognized
for ANSI standard classification.
DMX covers (and is an abbreviation for) Digital MultipleXed signals. It is the most common communica-
tions standard used by lighting and related stage equipment.
DMX provides up to 512 control “channels” per data link. Each of these channels was originally intended to
control lamp dimmer levels. You can think of it as 512 faders on a lighting console, connected to 512 light
bulbs. Each slider’s position is sent over the data link as an 8-bit number having a value between 0 and
255. The value 0 corresponds to the light bulb being completely off while 255 corresponds to the light bulb
being fully on.
DMX data is transmitted at 250,000 bits per second using the RS-485 transmission standard over two
wires. As with microphone cables, a grounded cable shield is used to prevent interference with other
signals.
There are five pins on a DMX connector: a wire for ground (cable shield), two wires for “Primary” commu-
nication which goes from a DMX source to a DMX receiver, and two wires for a “Secondary” communication
which goes from a DMX receiver back to a DMX source. Generally, the “Secondary” channel is not used
so data flows only from sources to receivers. Hence, most of us are most familiar with DMX-512 as being
employer over typical 3-pin “mic cables,” although this does not conform to the defined standard.
DMX is connected using a daisy-chain configuration where the source connects to the input of the first de-
vice, the output of the first device connects to the input of the next device, and so on. The standard allows
for up to 32 devices on a single DMX link.
Each receiving device typically has a means for setting the “starting channel number” that it will respond
to. For example, if two 6-channel fixtures are used, the first fixture might be set to start at channel 1 so it
would respond to DMX channels 1 through 6, and the next fixture would be set to start at channel 7 so it
would respond to channels 7 through 12.
The greatest strength of the DMX communications protocol is that it is very simple and robust. It involves
transmitting a reset condition (indicating the start of a new “packet”), a start code, and up to 512 bytes
of data. Data packets are transmitted continuously. As soon as one packet is finished, another can begin
with no delay if desired (usually another follows within 1 ms). If nothing is changing (i.e. no lamp levels
change) the same data will be sent out over and over again. This is a great feature of DMX -- if for some
reason the data is not interpreted the first time around, it will be re-sent shortly.
In summary, since its design and evolution in the 1980’s DMX has become the standard for lighting con-
trol. It is flexible, robust, and scalable, and its ability to control everything from dimmer packs to moving
lights to foggers to lasers makes it an indispensable tool for any lighting designer or lighting performer.