Digitrax DN126M2 User manual

© 2014 Digitrax, Inc. www.digitrax.com— 1 —
Features:
▪FX3Function outputs for prototypical lighting eects and on/o control:
Constant Brightness Lighting with directional or independent control.
Optimized selectable LED or incandescent lamp operation
Realistic Eects like Ditch lights, Mars lights, strobes, and many more
Congurable Pulse Function available on all function outputs.
FX3 & Standard Function Qualiers operate functions based on direc-
tion, F0 on or o, direction and F0, and whether loco is moving.
Function Mapping for custom function setup.
Master Light Switch turns o all lights & functions with one keystroke.
Advanced Consist Function Controls.
▪Digitrax LocoMotion®System-Your locomotives look like the real thing.
The Digitrax LocoMotion System makes them run like the real thing too!
Scaleable Speed Stabilization (Back EMF) with simple setup & 256
level resolution.
Torque Compensation.
128 Speed Step operation (14 or 28 steps can also be used).
Momentum with acceleration and deceleration.
Normal Direction of Travel is user selectable.
Switching Speed feature for easier and faster access to yard speeds.
3 Step Speed Tables set start, mid and max voltage for custom control.
28 Step Speed Tables with 256 level resolution for precise control.
▪Program CVs using any Digitrax Compatible Control system without having
to buy any extra equipment.
▪2 Digit and 4 Digit Addressing.
▪Basic, Advanced & UniVersal Consisting.
▪SuperSonic motor drive for silent operation.
▪DIRect mode programming.
▪Decoder Reset CV with or without speed table reset.
▪Transponder Equipped ready for transponding on your Layout.
▪Motor Isolation Protection helps prevent damage to your decoder.
▪Automatic Analog Mode Conversion when running on DC layout.
▪Decoder Lock for individual programming of multiple decoders in one loco.
▪Digitrax “No Worries” Warranty.
DN126M2
Fits Micro Trains Line SW1500
Locomotive
.418” x .621” x .107”
10.63mm x 15.79mm x 2.72 mm
N Scale
Mobile Decoder
DCC Board Replacement
1.5 Amp/2 Amp Peak
2 FX3 Functions, 0.5 Amp
Complete Train Control
Run Your Trains, Not Your Track!

© 2014 Digitrax, Inc. www.digitrax.com— 2 —
Parts List
1 DN126M2 Function Decoder
1 Instruction Sheet
Installation Information
See the Digitrax Decoder Manual V2 for complete decoder test procedures, instal-
lation instructions, programming and technical information. Digitrax manuals
and instructions are updated periodically. Please visit www.digitrax.com for the
latest versions, technical updates and additional locomotive-specic installation
instructions. CAUTION: Programming and layout track must not exceed
16V when using this decoder.
Installation Instructions
1. Carefully remove the fuel tank cover
and the locomotive’s shell from the
frame. Be extra careful to not
damage the pickups attached
to the locomotive shell, not
spreading the shell sides ade-
quately with e.g. toothpicks may
lead to the contacts catching
and being damaged as the shell
is being removed from the chas-
sis. (Figure 1) Notice the orientation
of the shell to the frame (Figure 2)
so that you can reinstall the shell
correctly.
2. Gently remove the wires from the
factory light board by pulling them
up and out of the sockets. (Figure 3)
3. Slide the factory light board forward
and out of the locomotive frame.
4. Install the DN126M2 by sliding it
back into the slot where the factory
light board was removed. Insert the
wires into the corresponding sockets
on the DN126M2. (Figure 4)
5. Replace shell and fuel tank cover.
Be extra careful to not damage the
pickups attached to the locomotive
shell. You are now ready to run your
locomotive. The DN126M2 is factory
programmed to address 03. You can
easily customize the address and
other features. See section “Customizing Your Decoder” that follows.
Figure 1. Removal of shell
Figure 2. Shell removed
Figure 3. Remove Factory Light Board
Factory Light board
Gently remove wires
Toothpicks
Shell Pickups

© 2014 Digitrax, Inc. www.digitrax.com— 3 —
Customizing Your Decoder
Your Digitrax decoder is ready to run
and will operate using address 03 with
no additional programming. For a more
prototypical railroading experience,
your decoder can be customized for your
specic locomotive by programming
some of the Conguration Variables, or
CVs, available. See the Digitrax Decoder
Manual or the Digitrax web site for more
information.
Changing the Decoder Address
The rst CV most people change is the decoder address. This allows you to inde-
pendently control each loco with a unique address. Digitrax decoders are shipped
with CV01 (AD2), the two digit address, set to 03. Following is a brief description
of how to change the decoder address with a Digitrax DT4XX series throttle. See
your Starter Set Manual for complete programming instructions.
1. Go into DIRect Mode Programming on your system On the DT4XX
throttle press PROG until DIR is displayed.
2. Choose AD2 for 2 digit addressing or AD4 for 4 digit addressing.
3. Choose the address you want to set up for the decoder.
4. Complete address programming by pressing ENTER.
Note: CV29 must also be programmed to enable 4 digit addressing, this is done
automatically by the DT4XX throttles. See your Digitrax Decoder Manual or the
Digitrax Toolbox App for how to set up CV29.
Digitrax LocoMotion®System
Your locomotives look like the real thing, now you can make them run like the
real thing, too. Digitrax decoders incorporate torque
compensation for smooth as silk operation. You can also program CVs that
control momentum, 3 step and 128 step speed tables, switching speed, normal
direction of travel, scalable speed stabilization and more to take full advantage of
the Digitrax LocoMotion System.
Figure 4. Decoder Installed
Decoder Installed
Wires inserted in decoder

© 2014 Digitrax, Inc. www.digitrax.com— 4 —
Momentum-CV03 & CV04
Momentum is part of the LocoMotion System. Acceleration is controlled by CV03
and deceleration by CV04. Both come from the factory set to 000. A range of 000
to 031 is available for both accel and decel. Try CV03:003 and CV04:000 as a
starting point for experimenting with momentum.
Speed Tables-How the Loco Responds to the Throttle
With Digitrax LocoMotion, there are two types of speed tables: 3 Step Tables
and High Resolution 28 Step Tables. Please see your Decoder Manual V2 for a
discussion of the 28 Step Tables. The 3 Step Tables are set up by programming 3
CVs: Start Voltage (CV02), Mid point Voltage (CV06) and Max Voltage (CV05).
These values are set at 000 at the factory. All have a range of values from 000 to
255. We recommend the following CV values as a starting point for experiment-
ing with speed tables.
Loco Type V Start
CV02
V Mid
CV06
V Max
CV05
Switcher
Concentrated low speed. Limited top
speed
002 038 064
Road Switcher
Prototypical top speed w/evenly
distributed curve from 0 to top speed
002 048 098
Mainline Loco
Quick increase to cruising speed then
levels o to prototypical top speed.
002 128 154
Other LocoMotion®Features: Switching Speed, Normal
Direction of Travel & Scalable Speed Stabilization
(Back EMF) Features
Switching speed is controlled by CV54. The factory setting is 000 for OFF. To
turn on the switching speed feature, program CV54 to a value of 001. When this
feature is on, use F6 to activate and deactivate switching speed. With the feature
on the throttle’s target speed is eectively reduced by about 50% and the eects
of accel and decel programmed into the decoder are reduced by 1/4. This is useful
for yard switching operations.
Normal Direction of Travel is controlled by CV29. See your decoder manual
or the Digitrax Toolbox App for additional information on the settings for CV29.
The intensity, or droop, of Scaleable Speed Stabilization (Back EMF) is

© 2014 Digitrax, Inc. www.digitrax.com— 5 —
controlled by CV57. The factory setting for this feature is 006 which is suitable for
most locos. You can adjust this value in the range of 000 for OFF to 015 for the
maximum eect. Consult your Digitrax Decoder Manual for info about CVs 55 &
56 and their eects on scaleable speed stabilization.
SuperSonic Silent Operation and Torque Compensation
The factory settings in the decoder provide silent, smooth operation of your loco-
motive under most conditions. For more information about these settings, please
see the Digitrax Decoder Manual or our website.
Digitrax Transponding CV61
Digitrax Transponding is controlled by CV61. The initial factory set value is 000
for OFF. To turn on transponding, program CV61 to a value of 002. This al-
lows you to use Digitrax transponding to keep track of your rolling stock. When
transponding is enabled, the front light of the locomotive will icker slightly to
indicate transponding signal is being communicated.
Decoder Reset CV08
Decoder reset lets you reset all CV values to the initial factory settings. To reset all
CV values, program CV08 to a value of 008. You also have the option of reset-
ting all the CV values except the 28 speed step tables and CV60 selected sound
scheme. To do this program CV08 to a value of 009.