MTH 50-1039 ProtoSound DCS WiFi Track Interface Unit TIU/WTIU Digital Command System 2

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Scale O
Number 50-1039
Manufacturer MTH Trains

Today's DCS Digital Command System features an all-in-one WiFi Track I.nterface Unit (WTIU) that brings true interactive wireless control to a model railroad. Users utilize their own smart device — iOS or Android — and an intutive app to run multiple tracks, hundreds of trains and control switches and accessories using the separately sold AIU Accessory Interface Unit. Bi-directional communication between locomotives and the system’s WTIU makes adding and programming locomotives simple and easy. No more ID numbers to remember and no complex icons to decipher. It’s fast, it’s easy and it’s fun!

Regardless of how you control it, DCS is compatible with all Proto-Sound 2.0 or 3.0 equipped locomotives as well as S Gauge and O Gauge locomotives equipped with Lionel® TMCC® and Legacy™ onboard systems; any conventional AC-powered locomotives; or conventional analog DC-powered locomotives in other scales, including N, HO, and G Gauge.

Featuring four channels, the new WTIU can now control conventional AC or DC locomotives allowing the user to control command and non-command equipped locomotives on the same track at the same time. The WTIU sets up in seconds and doesn’t require a home WiFi system to operate and can receive commands from an unlimited number of smart devices.

Please Note: The previous TIU units ARE NO longer made by MTH.

The 50-1039 is the replacement for the Old TIU and is designed only to be used with the Wifi App 


  • All-In-One Command Control Transmitter
  • Built-In WiFi
  • 4-Channel Output With Fixed and Variable Voltage Ports
  • 4-Channel AC or DC Power Input Ports
  • Auxiliary Power Input Port
  • USB Input Port
  • RS-232 Serial Port
  • Ethernet Input Port
  • LED Activation Lights
  • DCS Handheld Remote Tether Input
  • AIU Accessory Interface Unit Input
  • (2) Fixed AC and DC Voltage Output For Command Control Tracks
  • (2) Variable AC and DC Voltage Outputs For Conventional and Command Control Tracks
  • Wireless WiFi Control (iOS or Android) Using DCS App
  • Tethered Layout Control Using DCS Handheld Remote



In conventional model train operation, an AC or DC transformer varies track voltage to adjust engine speed and direction. Command systems such as DCS, however, put a constant voltage on the track (around 18 volts for DCS) and vary speed by telling each engine how much of that voltage to use.

Unlike conventional control, command control allows different engines to do different things, even when they are on the same track — like run at different speeds, go in different directions, or make different sounds. You can even combine several engines into a “lashup,” working together under a single throttle.

How it works: In the DCS system, commands such as speed, direction, and sound control are sent as radio signals from a smart device to a receiver, which translates those signals into digital information. That digital signal is sent through the rails and picked up only by the appropriate engine — telling it to go, for example, 37 miles per hour, blow the whistle, or smoke more heavily.



The DCS System is simple to hook up. You’ll have trains running in just minutes using the handheld or the App!

Each WTIU Fixed Input Channel can handle either AC or DC power. You can even mix and run one channel with DC power and the other with AC. This makes it easy to run HO Proto-Sound 3.0 equipped trains using the same WTIU you use to run all other Proto-Sound 2.0 or later locomotives.

Each WTIU Variable Input Channel accepts AC or DC power from virtually all AC or DC power supplies, including all M.T.H. AC transformers like the Z-4000, Z-1000, Z-750 and Z-500.

Once you’ve got power into the TIU, run the outbound channels directly to the track or to a terminal block for larger layouts. We recommend wiring the channels to the track in 15’ sections to best distribute power and the DCS digital signal. Full details are explained in the DCS User Guide.



Coupler Operation
Volume Increase
Engine Start Up
Engine Mute
Volume Decrease
Engine Shut Down
Headlight On/Off
Proto-Cast On/Off
Passenger Station/Freight Yard Proto-Effect Announcements
Doppler On/Off
Bell, Horn, Engine/Accent Volume
Chuff Rate
Cab Chatter
Squeaking Brakes
Wheel Clickty Clack
Custom Sounds
Auto Coupler Slack
Doppler Loop


Smoke Output Intensity Level Control
Smoke On/Off
Smoking Whistle
Headlight On/Off
Ditch Light Control
Maximum Engine Speed
Acceleration Rate
Deceleration Rate
Direction Startup Control
Labored Smoke
Brake Boost


Emergency Stop
SoftKey Operation
Remote Control Backlight
Remote Control Microphone
Lashup creation
Route Creation
Scene Creation
Session Record/Playback
Resetting Engine Features
Reading Engine Information
50 or 60Hz AC Power Selection Input
Operate TMCC/Legacy Engines
Edit TMCC/Legacy Engine Address
Operate Conventional Engines
Switch And Accessory Operation

More Information
Item # 50-1039
Preorder Yes
Scale O
Roadnumber May Vary No
Power & DCC Supplies Power Supplies & Transformers, Wireless