LSC Lighting EKO - Manual (Page 41)

EKO Dimmer
Operator Manual V2.3
LSC Lighting Systems (Aust) Pty. Ltd Page 37
10 DMX Explained
DMX512/1990-A is the industry standard for the
transmission of digital control signals between
lighting equipment. It utilises just a single pair of
wires on which is transmitted the level
information for the control of up to 512 DMX
slots (addresses or channels).
The information for each slot is sent
sequentially. The level of slot 1 is transmitted,
then the level of slot 2, then 3, etc. up to a
maximum of 512 slots. This stream of data
containing the levels for all 512 DMX slots is
repeated a minimum (generally) of 44 times per
second. This provides sufficient updates of
channel information for smooth fade transitions.
As the DMX512-A signal contains the level
information for all slots, each piece of equipment
needs to be able to read the level(s) of the
slots(s) that apply only to that piece of
equipment. To enable this, the EKO dimmer has
a “DMX Patch” menu that allows you to patch
(connect) each DMX slot (address) from your
lighting controller to an EKO dimmer channel
number or to multiple dimmer channel numbers.
When good quality data cables are used,
DMX512 cable runs may be up to 1,000 metres
in length. When several DMX feeds are required
(to feed different locations), DMX512 splitters
must be used. These provides multiple isolated
DMX512 feeds.
The EKO uses a high impedance DMX input
circuit allowing you to loop the DMX signal from
one EKO to the next. The last EKO in the chain
must have the “DMX Terminate switch” set to
TERM to terminate the line.
Note:
Do not use unscreened microphone or
low speed data cables for DMX. This can cause
problems in the DMX network. Make sure the
cable conforms to the EIA485 cable
requirements by providing the following
specifications:
• Low capacitance
• One or more twisted pairs
• Foil and braid shielded
• Impedance of 85 -150 Ohms, nominally 120
Ohms
• 22AWG gauge for continuous lengths over
300 metres
The following diagrams illustrate some simple
setups utilising DMX512.
10.1 TYPICAL DMX INSTALLATIONS
In the following example, the DMX output signal
from the lighting control desk is fed to the DMX
connector of the first EKO dimmer. The DMX
cable is then looped to the following EKO
dimmers. The order of the daisy chaining is not
important as each EKO dimmer channel can be
patched to any DMX slot number. The end of the
DMX line is terminated to prevent the signal
reflecting back up the line and causing possible
errors.
In the next example, the DMX is first fed to a DMX splitter which isolates the outputs. Separate DMX
cables are then run to the various locations where the EKO’s are installed. In the event of a fault on one
of the cables, the other outputs from the splitter will not be affected.
EKO
DMX
Slots
61-66 EKO
DMX
Slots
49-60 EKO
DMX
Slots
25-48 EKO
DMX
Slots
1-24
Lighting
Controller
Termination
Switch set
to TERM DMX
Cable