Lightronics RD-122 User manual

www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
RD122
RACK MOUNT DIMMER
OWNER’S MANUAL
VERSION 1.4
11/23/2021

Page 2 of 11
RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
UNIT DESCRIPTION AND FUNCTIONS
The RD122 is a 28,800 Watt, 12 channel, rack
mountable dimmer. Each of the channels has a
capacity of 2400 Watts. It is controlled via low
voltage signals which may be LMX-128 (3 wire
multiplex) or USITT DMX-512. The unit is fan
cooled. Channels may be independently assigned
from the unit. The unit is over temperature protected
and has a magnetic circuit breaker for each channel.
There are three options for channel output
connection panels. Options include: Duplex outlet
panel with 1 connection per channel, External
terminal strip (includes knockout cover) and
Socapex connector panel (wiring per customer
selection). The RD122 has several stand alone
functions which enable it to operate without a control
console. These functions include a storable scene
which may be activated by an external switch
closure, a programmable chaser and 7 factory set
chase patterns.
POWER REQUIREMENTS
Each RD122 requires both hots from a SINGLE
PHASE 120/240 VOLT AC or TWO PHASES OF A
THREE PHASE 120/208 VOLT AC service. The
neutral conductor is shared by two hots so it is
important the two hots used are of different phases.
EACH PHASE must be capable of providing 120
AMPS. Line frequency is typically 60HZ. A 50HZ
model is available for export. Refer to the dimmer
electrical rating markings to determine the operating
frequency. One or more RD122 dimmers may be
installed into a standard 19" equipment rack with
provisions for connection to an appropriate electrical
service in accordance with the National Electrical
Code.
INSTALLATION
PLACEMENT
The RD122 is designed to be mounted in a standard
19" equipment rack using the four mounting holes in
the face plate of the dimmer. If the dimming system
will be used for touring shows, it is recommended
you provide additional support for the rear of the
unit. The dimmer is fan cooled and requires no
space between units when multiple dimmers are
used. Air enters the dimmer through slots on the
side and exits through holes in the bottom of the
face plate. Make certain these ventilation holes are
not obstructed. Do not place the RD122 where it will
be exposed to moisture or excessive heat. The
RD122 is intended for INDOOR USE ONLY.
POWER CONNECTIONS
Consult your local electrical codes to determine the
proper wire type and wiring methods for your
installation.
Power enters the RD122 through a knockout sized
for 1” conduit at the rear of the unit. Remove the top
cover and install an appropriate cable clamp in the
knockout hole. Pass the power cables through the
hole. Behind the hole is a terminal block with three
lugs. The connections labeled "H1" and "H2" are the
line connections or "hots". The center connection
labeled "N" is the neutral. There is an additional lug
labeled "G" to the right of the terminal block. This is
for connecting the unit to earth ground. When
connections are completed, reinstall the cover and
tighten the cable clamp.
OUTPUT CHANNEL CONNECTIONS
The RD122 can be supplied with one of several rear
panel output options. Channel output connections
are according to the rear panel selected. Channel
connections generally proceed from left to right (if
you are facing the rear of the unit). Channel “1” will
be on the left end. On a unit supplied with edison
plug outlets, channels 1 - 6 are on the top row (from
left to right). Channels 7 - 12 are on the lower row
(from left to right). Connections for load Neutrals are
provided. There is also a ground lug terminal to be
used for your load circuit grounds.
CONTROL SIGNAL CONNECTIONS (Units with
DB9 connectors)
A control signal enters the RD122 through
connectors on the rear of the unit. If you are using
the 3 pin multiplex protocol ("LMX" or compatible),
plug the control cable into the 3 pin "XLR" connector.
If you are using the DMX-512 protocol, plug your 5
pin DMX control cable into the 5 pin to 9 pin adapter
supplied with the RD122 and plug the 9 pin
connector into the upper 9 pin connector on the rear
of the dimmer. In either case, the lower 9 pin
connector and the ribbon cable jumper that is
supplied can be used to connect from the lower
connector of the first dimmer into the upper
connector of the next dimmer and so on. See the
WARNING
MAKE CERTAIN POWER IS
REMOVED FROM THE FEED
CIRCUITS BEFORE YOU BEGIN
INSTALLATION.

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RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
included drawings at the back of this manual for
clarification. The RD122 is shipped with the power
supply set to provide +15 volts DC console power
when using the 3 pin multiplex protocol. Note the
DMX-512 protocol does NOT provide a means for
console power via the control cable. Systems using
the DMX protocol must have console power supplied
by other means.
CONTROL SIGNAL CONNECTIONS (Units with 5
pin DMX & 7 pin Phoenix connector)
A control signal enters the RD122 through
connectors on the rear of the unit. You can plug the
5 pin control cable into the 5 pin XLR connector or
connect individual wires into the 7 pin Phoenix
connector. Connections to additional DMX devices
can be made via the lower 5 pin XLR connector or
into the 7 pin Phoenix connector. See the included
drawings at the back of this manual for clarification.
SETUP
The RD122 has a front panel LCD display and
operator controls. The display indicates dimmer
status information and is used with the operator
control buttons to set up and monitor dimmer
operation. A menu system is used to access the
various features of the RD122. During normal
dimmer operation the display shows the current
intensity setting for each channel and indicates what
type of dimmer control is in effect. This is called the
STATUS DISPLAY and is shown in the diagram
below.
RESETTING THE UNIT
The RD122 may be reset to a "factory provided"
configuration by holding down the MENU button on
the front panel for about 5 seconds. A message
"SYSTEM RESET" will appear on the front panel
LCD display. Release the MENU button when you
see the message. Resetting the unit causes the
following actions:
1. Channel patch is set to 1 to 1.
2. All channels are set to DMR (relay mode turned
off).
3. The external switch sensing function is turned
off.
4. The internally stored scene is turned off (it is
not erased).
5. The programmable chase pattern is turned off
and erased.
6. Chase parameters are set to a default set of
conditions. The Default conditions are given in
the table under the section CONTROLLING
CHASER CHARACTERISTICS.
You should perform a setup procedure before using
the unit. Setup includes (1) Setting the channel
assignments the dimmer will respond to and (2)
Setting individual channels to “DMR” or “RLY”
(relay). Once the setup is completed the unit will
retain the settings until changed by the operator
(including when the unit is powered off and
restarted).
ASSIGNING DIMMER CHANNELS (CHANNEL
PATCHING)
The RD122 has 12 dimming channels labeled 1-12.
Each of these channels may be assigned to any
console channel number from 1 to 512. Multiple
dimmer channels may be assigned to a single
console fader if desired. This gives you the ability to
soft patch at the dimmer itself.
TO ASSIGN DIMMER CHANNELS:
1. Press the MENU once to enter the patch mode.
The display will indicate “PTCH”.
2. Push SELECT. The left display bar graph
channel (for dimmer channel A) will flash and
the currently assigned console channel will be
shown on the display bottom row. Use the UP
and DOWN arrow buttons to change the
console channel assignment for channel 1.
3. Push SELECT to advance to the next dimmer
channel. Continue to assign channels through
channel 12.
STATUS DISPLAY AND
OPERATOR CONTROLS
CSD
CHANNEL LEVEL
BARGRAPHS
CONTROL SIGNAL
INDICATOR
D = DMX
L = LMX
= No Signal
CHASER INDICATOR
C = Chaser Active
= Chaser Off
SCENE INDICATOR
S = Scene Active
= Scene Off
MENU
SELECT
OPERATOR CONTROL BUTTONS
1 2 345 6 78
910 11 12

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RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
4. Push MENU three times to return to the normal
operation mode.
TO SET CHANNELS TO DIM OR NON-DIM
(RELAY):
1. Press MENU twice. The LCD display will
indicate “NDIM”.
2. Push SELECT. The left display bar graph
channel (for dimmer channel 1) will flash. The
display will show “DMR” or “RLY” on the
bottom row according to the current setting.
3. Use the UP and DOWN arrow buttons to
change between dimmer and relay modes for
that channel.
4. Push SELECT to advance to the next dimmer
channel. Continue to set channels through
channel 12.
5. Press MENU twice to return to the normal
display.
MANUAL OPERATION
Dimmer channels can be operated manually from
the dimmer front panel. Press the SELECT button
until the desired channel's "bar graph" is flashing.
Press the UP or DOWN arrow buttons until the
desired level is reached. Press the SELECT button
to advance to other channels. To return control to
your console, press the SELECT button until you go
PAST the last channel and stop. After approximately
6 seconds the dimmer will return to console control.
A channel continues to respond to console settings
when operating from the front panel unless you
change the level for that channel at the dimmer front
panel. Once this occurs - that channel will NOT
respond to console settings until you return to
normal console control.
NORMAL OPERATION
As you operate faders on your console, the
associated channel levels are indicated on the
RD122 display. The display will also indicate any
abnormal conditions such as over temperature. The
fan will run at full speed whenever there is a control
signal present and one or more faders are at full on.
The fan will drop to half speed a few minutes after all
faders are lowered to full off and will stop shortly
after the control signal is removed.
INTERNAL SCENE OPERATION
The RD122 has the ability to internally save a single
scene which may be activated remotely. The scene
remains in the unit’s memory when it is shut off and
will be available the next time the unit is powered on.
A saved scene is not lost when the unit is reset.
TO SAVE A SCENE:
1. Create the scene from a control console or from
the front panel of the dimmer itself by activating
the applicable channels.
2. Press and hold the front panel SELECT button
until you see the front panel display appears as
shown below (You will have to hold the button
down for about 6 seconds):
3. Push SELECT. The display will show the
message:
4. The scene has been recorded when the LCD
reverts to its normal display.
TO ACTIVATE A STORED SCENE:
A scene previously stored in the RD122 is activated
by connecting together Switch Input & Switch
Common (Pins 6 and 7 of the 7-pin Phoenix
connector or pins 5 and 9 of either DB9 connector
depending on the rear plate design). The
connectors are on the rear of the dimmer. This may
be done via a remotely located switch. The
activated scene will remain active as long as a
closed circuit is maintained between these pins.
In addition to activating a scene, the RD122 can be
set to ignore the remote switch or activate chaser
functions. In order to use the remote switch for
internal scene activation you must enable that
function as follows:
1. Push MENU 3 times. The display will show the
message "MENU" on the bottom row.
2. Push SELECT. The LCD will display one of the
messages shown below.
3. If "Not Used" or "Chaser" appears on the
bottom row, push the UP or DOWN until
"Scene" appears.
Scene 
Save #01
SAVING
NOW !
Input1 
Scene
Input1 
Chaser
Input1 
Not Used

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RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
4. Push SELECT to return the unit to normal
operation.
The front panel display shows an "S" on the bottom
row as an indication that an internal scene is active.
NOTES ABOUT INTERNAL SCENE:
The RD122 continues to respond to control console
signals when the internal scene is activated. The
intensity of any given channel will be the "greatest
of" or "pile on" result of the internal scene and
console level setting.
If multiple RD series dimmers are connected as a
system (See CONTROL SIGNAL CONNECTIONS),
then a remote switch connected to the system can
activate system wide scenes or only scenes in
specific dimmers depending on how the remote
switch function is set in each dimmer. These scene
features give you the ability to use the dimmer for
house lights and other applications where it is not
practical to operate a control console.
CHASER OPERATION
The RD122 can operate chaser functions as a
"stand alone" unit with no control console present.
There are 7 factory set chase patterns embedded in
the unit software. There is also one pattern which
may be programmed by the user. The chase step
rate, chase step fade rate and chase intensity can
be set by the user for all chaser functions. Chaser
functions may be set to run continuously or as a
single occurrence. The number of steps (up to 32)
can be set for the programmable chase. The RD122
may be set to begin chaser functions at "power up"
or in response to a remote switch. A bounce option
can be imposed on a chase pattern. This results in a
pattern which runs in its normal sequence then runs
the same sequence backwards.
ACTIVATING A CHASE PATTERN
A chase stored in the RD122 is activated by
connecting together Switch Input and Switch
Common (Pin 6 and 7 of the 7-pin Phoenix
connector or pins 5 and 9 of either DB9 connector
depending on the rear plate design). The
connectors are on the rear of the dimmer. This may
be done via a remotely located switch. The
activated chase will remain active as long as a
closed circuit is maintained between these pins.
In addition to activating a chase, the RD122 can be
set to ignore the remote switch or use it to activate a
scene. In order to use the remote switch to activate
chase patterns you must enable that function as
follows:
1. Push MENU 3 times. The display will show the
message "MENU" on the bottom row.
2. Push SELECT. The LCD will display one of
messages shown below.
3. If "Not Used" or "Scene" appears on the bottom
row, push the UP or DOWN arrow buttons until
"Chaser" appears.
4. Push SELECT to return the unit to normal
operation.
The Front panel display shows a "C" on the bottom
row as an indication that an internal chase is active.
SELECTING A CHASE PATTERN
You can select any of the 7 factory preset chase
patterns to run or create and run your own custom
pattern. Instructions for creating a custom chase
pattern are given further on in this manual.
A chase pattern is selected using the RD122 menu
system as follows:
1. Push MENU 3 times. The LCD will appear as
shown:
2. Push SELECT. Then push MENU. The LCD
will appear as shown: The bottom display row
shows the currently selected pattern. The
pattern "4Ch Seq" is shown as an example.
3. Use the UP and DOWN arrow buttons to scroll
through the available chase patterns. Push
SELECT when the desired pattern appears.
Note: Remember this action does not activate the
chase pattern. This action selects which pattern will
be run when activated by the remote switch function.
Input1 
Scene
Input1 
Chaser
Input1 
Not Used
MENU
Chase# 
4Ch Seq

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RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
The available patterns are:
4 CHANNEL SEQUENCE
8 CHANNEL SEQUENCE
4 CHANNEL BUILD
12 CHANNEL SEQUENCE
6 CHANNEL SEQUENCE
RANDOM
6 CHANNEL BUILD
PROGRAMMABLE
CONTROLLING CHASER CHARACTERISTICS
You can control seven characteristics of a chase
pattern. These controls are described as follows:
**Overrides remote switch setting.
The default setting is the factory set value.
All of these characteristics can be set via the RD122
menu system. See the diagram STRUCTURE OF
MENU SYSTEM for a complete layout of menu
system operation.
CREATING YOUR OWN CUSTOM CHASE
PATTERN
The programmable chase pattern is created by
setting the intensity for all dimmer channels for each
step in the chase. The chase step is then recorded.
This action is then repeated for each additional step
to be recorded. The channel intensities can be set
either from the RD122 front panel as in manual
operation or by using a control console.
TO SAVE A CHASE STEP:
1. Create the step from a control console or from
the front panel of the dimmer itself by activating
the applicable channels. Channel intensities
are recorded as either full ON or full OFF. If
you want a given channel to be on for a chase
step then the channel must be set to greater
than 50 % intensity. Note that the overall
intensity of the whole chase pattern may be set
using the menu system.
2. Press and hold the front panel SELECT button
until the front panel display appears as shown
below (You will have to hold the button down for
about 6 seconds):
3. Push the UP arrow button. The display will
appear as follows:
This is the display for chase step #1. If you
want to record to another step number - use the
UP and DOWN arrow buttons to make the
correct step number appear on the lower
display row.
4. Push SELECT. The display will show the
message:
5. The chase step has been recorded when the
LCD reverts to its normal STATUS DISPLAY.
The above recording process is repeated for each
step in the programmable chase pattern. See the
section CONTROLLING CHASER
CHARACTERISTICS for information about how the
chase can be made to appear when activated.
MAINTENANCE AND REPAIR
FRONT PANEL BREAKERS AND FUSES
The RD122 has two fuses. The left fuse is 1 Amp.
The right fuse is 1/4 Amp. Both are 250V, 1.25 x .25
Chase
Rate
The duration of each chase step (.25
- 999.75 seconds).
Default = 1 Second
Chase
Fade Rate
The time for each step to reach
maximum intensity
(0 - 100% of step time).
Default = 100%
Chase
Intensity
The overall brightness of the chase
(0 - 100%)
Default = 100%
Chase
Steps
The maximum number of steps in the
chase (1 - 32) Default = 4
Chase
Bounce
Causes reversal at the end of each
sequence (Ignored during
RANDOM). Default = Off
Continuous
/Single
Enables/Disables a "one shot" chase
occurrence (Ignored during
RANDOM). Default = Continuous
Activate
Chase at
power up
Enables chase to begin automatically
when dimmer is turned on. ** Default
= Off
Chs Stp
Save #01
Scene 
Save #01
SAVING
NOW !

Page 7 of 11
RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
inch, fast acting fuses. These fuses provide
protection for the internal electronic control circuitry
and the fan. They may be replaced ONLY by fuses
of identical type and size.
Each channel of the RD122 is protected by a 20
Amp, fast acting, magnetic circuit breaker located on
the front panel of the unit. If the total load for a
channel is greater than 2400 Watts the channel
circuit breaker will trip.
TROUBLESHOOTING
VERIFY ALL POWER IS REMOVED FROM THE
DIMMER BEFORE HANDLING THE UNIT.
1. To simplify troubleshooting - reset the unit to
provide a known set of conditions.
2. Check the console is powered and the console
channels are correctly patched or set.
3. Check the control cable between the dimmer
and console.
4. Verify the loads and their connections.
OWNER MAINTENANCE
There are no user serviceable parts inside the unit.
The best way to prolong the life of your unit is to
keep is cool, clean, and dry. It is important the
cooling intake and exit vent holes are clean and
unobstructed.
Service by other than Lightronics authorized agents
may void your warranty.
OPERATING AND MAINTENANCE ASSISTANCE
If service is required, contact the dealer from whom
you purchased the equipment or contact Lightronics,
Service Department, 509 Central Drive, Virginia
Beach, VA 23454 TEL [phone]. All items
returned for service must include a description of the
problem along with your name, address, and phone
number.
Lightronics recommends that you record the serial
number of your unit for future reference.
SERIAL NUMBER ______________________
WARRANTY INFORMATION AND
REGISTRATION –CLICK LINK BELOW
www.lightronics.com/warranty.html

Page 8 of 11
RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
STRUCTURE OF MENU SYSTEM
= Set Chase Pattern (4Ch Seq, 4 Ch Build, 6 Ch Seq,
6 Ch Build, 8Ch Seq, 12 Ch Seq, Random, Program)
SELECT =Exit
D
D
SELECT
SELECT
MENU
MENU
MENU
MENU
PTCH
001
SELECT
MENU
MENU
NDIM
DMR
SELECT
MENU
MENU
MENU
MENU
MENU
MENU
MENU
MENU
MENU
MENU
MENU
= Raise/Lower Intensity of Flashing Channel
SELECT = Advance to Next Channel
= Assign Console Channel to Flashing Dimmer Channel
SELECT = Advance to Next Channel
= Set Flashing Channel to Relay/Dimmer Mode
(RLY = Relay Mode, DMR = Dimmer Mode)
SELECT = Advance to Next Channel
= Set Remote Switch Function (Not Used/Chaser/Scene)
SELECT = Exit
= Set Chase Rate (.25 - 999.75 Sec. per step)
SELECT = Exit
= Set Chase Fade Rate (0 - 100% of step time)
FL% = 100%
SELECT = Exit
= Set Chase Intensity (0 - 100%)
FL% = 100%
SELECT = Exit
= Set Chase Max Steps (1 - 32)
SELECT = Exit
= Set Chase Bounce (Normal = OFF, Bounce = ON)
SELECT = Exit
= Set Chase run Normal/Single (Normal = Continuous)
SELECT = Exit
= Set Chase at Power Up (Normal = OFF, PwrUp - ON)
SELECT = Exit
Input1
Not Used
Chase#
4Ch Seq
ChsRate
001_ Sec
ChsFade
FL%
ChsInt
FL%
ChsStps
16 Steps
ChsBnce
Normal
ChsMode
Normal
ChsPwr
Normal
STATUS DISPLAY

Page 9 of 11
RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
REAR PANEL CONNECTION OPTIONS

Page 10 of 11
RD122 RACK MOUNT DIMMER
Version 1.4 OWNER’S MANUAL 11/23/2021
www.lightronics.com
Lightronics Inc. 509 Central Drive, Virginia Beach, VA 23454 [phone]
CONTROL SIGNAL CONNECTIONS
FOR LMX PROTOCOL
CONTROL SIGNAL CONNECTIONS
FOR DMX 512 PROTOCOL