The Digitrax TF4 is a quad-function DCC decoder with integrated transponding — four independently controlled function outputs on one tiny board, plus Digitrax's position-tracking feature built right in. Perfect for adding ditch lights, mars lights, rear markers, classification lamps, smoke generators, or any other DCC-controlled accessory cluster to a non-decoder locomotive.
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What's the difference between the TF4 and the TL1?
The TL1 has one function output; the TF4 has four. If you need to control multiple separate lighting circuits (headlight + ditch lights + class lamps + rear marker) the TF4 is the right call. Both have integrated transponding.
Does this drive a motor?
No — the TF4 is function-only. For motor + lights in one board, use a full mobile decoder like the Digitrax DH126 or DZ126.
What can I wire to the function outputs?
LEDs (with resistors), incandescent bulbs, smoke units, ditch lights, mars lights, signal lamps, sound modules — anything DC-driven under 1A combined draw. FX3 effects make each output simulate prototypical lighting patterns independently.
Will it work with any DCC system?
Yes — standard NMRA DCC. Transponding readback requires a Digitrax LocoNet command station with detection sections (BDL168, BDL16, etc.).
