Signal Decoder

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Summary: A subset of the Accessory Decoder, Signal Decoder outputs usually have two states: On or Off. By configuring them, various signal aspects can be created. Accessory Decoders require an accessory address, sometimes even several addresses. According to NMRA DCC standards, such addresses are intended for 4 turnouts (or 8 single functions). A sub-address identifies the 4 turnouts (or 8 single functions) which determines with which function key (F0, F1, F2, or F3) the switch in question is operated with.

Canadian National Signal 2028N, MP 202.8 is Mohawk, just west of Napanee, ON in October 1981

Available Signal Decoders

Team Digital

CSCe - Central Signal Controller

  • Built-in logic for automatically controlling signals
  • Configurable to model many signaling systems
  • Computer not required for signal control
  • Built-in signal configuration options
  • 16 outputs for LED indicators and Tortoise™ switch machines for turnout control
  • Two outputs for small servos
  • 16 inputs for occupancy sensors (block detectors), turnout state and push buttons
  • Serial bus reduces system wiring
  • LocoNet
  • DCC gateway to serial bus


Digitrax SE8C Signal Decoder

  • Control signals manually on your layout with a Loconet Throttle and Command Station
  • Automate with detection and compatible computer software
  • Drives as many as 32 signal heads of any popular LED type
  • Built in current limiting resistors for setting LED brightness
  • Drives up to eight semaphore signals with slow motion turnout machines
  • Can be used as an accessory decoder to control 8 turnouts
  • Each signal driver cable drives 4 heads
  • Includes a sample Signal Driver Cable and Test Signal Mast
  • Provides eight inputs for eight control lines for local turnout control
  • Provides eight inputs occupancy sensor links
  • For use with DC or DCC controlled layouts
  • Transponding is not necessary to implement signaling
  • A computer and third-party software are necessary to realize the full feature potential of the SE8C


NCE DCC Light-It Programmable DCC Lighting and Signal Decoder

Three programmable lighting outputs with a complete array of lighting effects.

  • DCC or DC (Limited functionality with DC)
  • NMRA Multifunction, Accessory or Signal Decoder addressing
  • Warm White LED on the PCB
  • Up to 3 Outputs / LEDs, may be controlled separately
  • Built-in series resistors for driving LED
  • Can function as an NMRA Signal Decoder
  • Each output individually dimmable
  • Modes - DC, Multifunction, Accessory, or Signal
  • 15 Lighting EFX
  • 18 Signal Aspects

Sig-Na Track

Was previously known as CML Electronics LocoNet and DCC messages control these signal decoders


Another good board for signal control is the SIGM10 which contains its own logic.

This device is no longer available and has been superseded by the SIGM20.


The SIGM20 is an automatic controller for eight signals. It sets the signal state automatically according to the state of the trackwork (turnouts), other signals and block occupancy detectors. It does this automatically, without any other computers involved: No computer is required to operate the railway. The board can control simple blocks, simple and complex junctions ... automatically.

The SIGM20 drives LED signals directly. Via optional adapters it drives incandescent lamp signals or semaphore signals controlled by Tortoise turnout motors. The behaviour for each signal is programmed: thereafter it operates automatically.

  • Drives either eight 3-aspect or six 4-aspect signals
  • Two more signals can be driven by an optional self-assembled add-on board.
  • LED signals: 2, 3 or 4 aspect or "searchlight" type.
  • Incandescent lamp signals can be driven using optional adapters
  • Semaphore signals operated by Tortoise motors can be driven using optional adapters
  • Simulation of "soft" lighting & dimming of lights: brightness ramps up or down over approximately half a second for more realistic looking signal lamps.
  • Fully compatible with the older SIGM10 - the two can be mixed on a layout seamlessly

More details: Sig-na Trak Website



  • Operate eight turnouts
  • Can drive 16 on/off switches, eight 2-light or four 3-light signals
  • Multiprotocol DCC/Motorola
  • Programmable via POM
  • 2.5 Amps



  • NMRA DCC Accessory Decoder compatible.
  • 16 outputs
  • Outputs are designed as push/pull power amplifiers, suitable for conventional common anode and/or common ground (common cathode)
  • Can also drive semaphore signals and turnout motors
  • LEDs from two, three or four-aspect daylight signals can be connected directly to any of the outputs.
  • Each output can be programmed individually to generate continuous output, blinking or pulsed light.
    • Brightness and blinking frequency respectively number of pulses can be adjusted as desired. The same goes for the cross-fading times.
    • Prototypical lighting effects such as soft dimming, fluorescent lamp effect, faulty fluorescent lamp, gas lantern imitation, battery powered lighting, flickering light and many more assure a very realistic experience.
  • Random on/off switching and delayed switching (on and off)
  • Programmed sequences are possible.
  • Flexible mapping enables assignment of individual outputs to their respective addresses and switching modes. Any possible signal aspect can be created.
  • Preprogrammed with many European signal aspects
  • LokProgrammer recommended for programming



  • Built in aspect tables allow a complete mast to to be set with a single DCC packet using the NMRA signal control protocol,
  • Configure individual heads or lamps to be controlled independently.
  • Integrated current source
  • Common cathode or common anode LED wiring
  • No resistors are required and brightness is easily configured for each output independently with simple CV settings.
  • Flashing aspects are maintained within the SC1 to reduce the control system overhead to a minimum.
  • Fully configurable using configuration variables (CV’s)
  • Compatible with all major manufacturers
  • Automatic address allocation
  • Controls
    • 4 Two Aspect Signals
    • 2 Three or Four Aspect Signals
    • 2 Three Aspect Signals with Feather
    • Signals with multiple feathers
    • Searchlight Signals
    • SPAD signals and level crossings
    • 8 Dapol semaphore signals with the addition of a small “add on” board
  • Spare ports can be used to control lighting and offers a large array of special effects including MARS light, flickering oil lamp, flashing light, single and double strobe and more
  • Each output can be adjusted for brightness


LDT makes a number of signal decoders. See their webpage for more details, as there are many combinations and aspects possible.


10777 - Signal module

Two light signals Maximum 4 signal aspects Signals can be lamps or LED. Integrated logic switching for automatic block post operation. In combination with the brake generator (10779, discontinued), automatic switch-over to a brake signal is possible.

Z21 signal DECODER

The Z21 signal DECODER is a universally applicable DCC decoder for complex light signals. Updateable Extensively configurable RailCom compatible

Tam Valley Depot

DCC LEDecoder - 3 Output Lighting Decoder

  • Uses two DCC addresses.
  • Can be used with JMRI for signaling.
  • Can also be used for DCC controlled lighting of buildings and passenger cars.
  • The flicker function imitates arc welding, flickering lights and fires.

Train Tech

SC Colour Light Signal Controllers

  • Control colour light LED signals by DCC
  • One Touch DCC button - No Programming!
  • Screw terminals for wires - no soldering
  • Connect directly to LEDs - series resistors built in
  • Simple 2 wire connection to track or controller output
  • SC1 - Dual 2 Aspect Signal Controller
    • One or two 2 aspect signals
  • SC2 - 3 or 4 Aspect or 2 Aspect plus route Signal Controller
    • One 3 aspect or 4 aspect signal or a 2 aspect signal plus route.

Signal Controllers for Dapol Semaphore Signals


For Original Dapol Semaphore Signals

  • Controls one or two Original Dual N or OO gauge motorised Dapol semaphore signals by DCC
  • Each signal can be given a separate DCC address with their position controlled by the SC3 which also remembers that position.

Dual Dapol + Track sensor & switch inputs

  • Like the SC3, controls Two Original Dapol semaphore signals directly from a DCC track or bus.
  • Inputs for Track Sensors allowing Semaphore signals to operate automatically when Trains are sensed on the track!

For New Dapol Servo Semaphore Signals

  • Designed to power and control the new Dapol Servo controlled signals with three wire inputs for each signal.
  • Control one, two or a twin head (e.g., Bracket) servo signal
  • Assign to any DCC accessory address & run the two arms independently or together in Home-Distant pairs.
  • It also incorporates a regulated power supply to provide a stable safe voltage for the signals from the standard DCC track supply.
  • Easy and quick to connect, use and setup using One-Touch DCC.

New Dapol Semaphore Dual Servo Signal Controller with Track sensor inputs

  • Specifically designed for the new Dapol Servo controlled signals which have three wire inputs for each signal
  • Control one, two or a twin head (e.g., Bracket) servo signal
  • Can be assigned any DCC accessory address
  • Run the two arms independently or together in Home-Distant pairs.


Dapol Model Railway Company is a UK based manufacturer of model railway equipment. Dapol Signals refer specifically to models of UK signals manufactured and sold by Dapol.


  • MX820E
  • MX820D
    • 2 outputs. D version is waterproof
  • MX820V
    • 4 outputs
  • MX820X
    • 8 outputs, also can control one turnout motor
  • MX820Y
    • 8 outputs, also can control two turnout motors
  • MX820Z
    • 16 outputs
  • Open Collector outputs, positive common connection
  • Can be used with lamps or LEDs
  • LEDs require a series resistor

Further Reading

External Links