Category:DC Mode

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Overview - DC Mode

DC Mode, sometimes referred to as "Dual Mode" is a mode of operation which allows a DCC decoder top operate on DC powered rails. DC mode can be enabled or disabled at will using CV programming via CV 29. If DC Mode is enabled, and the decoder is powered up on DC power, it will operate lights, motor, and perhaps other functions as if on DCC power. What you will lose in DC compared to DCC control is the precise and granular level of individualized functions, sounds, and precision motor control. DC Mode operation will never grant you the same amount of control as is available through DCC, but TCS does attempt to give you options to gain back as many of those controls as possible.

Common DC Mode Questions

Question: Can my TCS DCC decoder run on DC power?

Yes! All TCS decoders are capable of operating on DC track power. This configuration is enabled by default on all non-sound TCS decoders. CV 29 can be modified to enable or disable DC operation on any TCS decoder.

Question: Why is my WOWSound decoder not operating sound functions on DC?

With the exception of OEM decoders/projects such as the Bachmann ACS-64 and Streamlined K4, version 4 and older WOWSound decoders do not feature DC sound operation.

Question: Can I program lighting effects on DC?

While it is not possible to perform CV programming or Audio Assist programming on DC, any configurations set on DCC will carry over to DC. For example, if your engine has been programmed to operate a Mars light, firebox flicker, or directional lighting, those settings will carry over into DC operation and behave as if on DCC.

Question: My DC motor/lighting is reversed but it works fine on DCC. Why?

On DCC, the track power is AC with encoded data and as such is not polarized. Due to this, the engine and decoder are only aware of what direction they are/should be going based on the information sent by the command station. Therefore, "forward" is merely a perspective. Conversely, on DC the track power is polarized. TCS decoders detect the (+) track power rail and base the direction of the motor and lighting depending on which rail is positive. If the track power leads (Red and Black) or motor leads (Orange and Grey) are connected backwards of their intended polarity, the decoder's interpretation/assumption of polarity will be backwards of reality and should be fixed. Make 100% sure your wires are connected properly if you plan to run on DC frequently or exclusively.

Question: Can I use Keep Alive® with DC Mode/Dual Mode Decoders?

Technically, Yes! A Keep Alive® device will provide power to a decoder, even while being supplied by DC rail power. The performance and discharge time of your Keep Alive® device will be reduced on DC power due to the lower average voltage not allowing the device to fully charge - That is, unless you run exclusively bullet trains!

However! It is important to keep in mind that Keep Alive® is also a DC power supply device. It is not possible to simultaneously use Keep Alive® while also attempting to use DC blocking/auto-stopping. These settings will conflict. Keep Alive®'s purpose is to supply the decoder with power during an interruption of DCC packets. Once the DCC signal is lost, the decoder will continue to execute the most recently received instruction(s) until the Keep Alive® is drained. If DC power were to be applied in place of DCC, the decoder would interpret this as Keep Alive® and continue in motion rather than coming to a stop. Note that DC auto-stopping is different than Asymmetrical Braking which would not be affected by Keep Alive®.


Below, you can find related articles and CV's related to DC Mode operation: