CHAPTER 4
DMX Programming Basics and Quick Start
42 DL.3 Digital Light User Manual
Determining a DMX Start Channel
Overview
The DMX Start Channel is the first channel of a device’s channel footprint on a DMX link. There
are 512 available channels on each DMX universe divided among all the devices in a particular
universe. A device must have a unique DMX channel range in order to respond independently to
controller commands. The DMX Start Channel is the first channel in that fixtures channel range.
To determine each device’s DMX S
tart Channel, identify the footprint of every device on the
universe. The device’s footprint is the number of consecutive DMX channels it requires and is
determined by the channels in the fixture’s protocol. The fixture’s DMX channel footprint must
not overlap any other device’s channel footprint on the link. When two devices on the same DMX
universe have overlapping channel footprints, one or both devices will be disabled or behave
erratically.
Once you have determined the footprint of your devi
ce, a simple formula for finding the last
valid Start Channel on a standard DMX512 link is:
512 – the unit’s channel footprint + 1
Digital Lighting Products
The channel range for your Digital lighting product will depend on the model, the Protocol mode
and the number of Graphic objects you select. DL.3 and new Axon media servers running
Version 2.0 fixture software all provide individual and composite graphical control for up to nine
Graphic Objects. DL.2 fixtures and original Axon servers can control up to four Graphic objects.
You can influence the footprint of the fixture on a DMX link with the protocol you select and the
number of graphic objects you implement.
#of Object
Layers
V2 Footprint on DMX512 Link V1 Footprint on DMX512 Link
DL.3 Axon DL.2
Early
Axon
DL.3 Axon DL.2
Early
Axon
0 76 55 76 55 56
35
56
35
1 121 100 121 100 94
73
94
73
2 166 145 166 145 132
111
132
111
3 211 190 211 190 170
149
170
149
4 256 235 256 235 208 187 208
5 301 280 246 225
6 346 325 284 263
7 391 370 322 301
8 436 415 360 339
9 481 460 398 377