Support - Lighting

Overview - Understanding Light Functions

TCS decoders follow the NMRA standards and specifications for lighting functions (Document S-9.1.1), including the color code. The full list of NMRA-standardized wire colors for lighting can be found below, as well as at the previous link.

While it may not make sense on some products without wires, it can be more complicated to define functions as "functions" due to the confusion between sound functions, light functions, and physical buttons on your handset.

To clarify, we like to delineate numerical functions like this:

• A "Button" with a number (0 -> 28) corresponds to the numbered "buttons" on the throttle or other controlling devices. On a physical throttle these would be the numbered buttons on the handheld. Similarly, in JMRI Decoder Pro this is the throttle you can pull up and use from your computer. If you use a cellphone or tablet, these are the buttons you can press on your screen.
• A "Function" is typically defined as an electrical output from a decoder. Sometimes, "functions" can be referred to as "outputs" for better clarity and to limit the confusion with sound functions. Numerals are assigned to each output to distinguish it from the rest. On an 8 function decoder, you have two "0" functions for forward and reverse per the NMRA standard. (0F and 0R count as TWO functions. 2 + 6 = 8)
• A "Function" and a "Button" are NOT required to be linked together. Functions may be assigned to other buttons using the remapping CV's. As an example, for Function 1 and Function 2 these CV's are 35 and 36 respectively. A value of 4 in both of these CV's will remap both of the function outputs to respond on Button 1 on your controller. HOWEVER! A "Function" will ALWAYS retain the same lighting effect CV as its output number. For example, CV51 corresponds to Function 1 and CV52 corresponds to Function 2. Regardless of what button these function outputs are mapped to, their effect CV's will continue to reflect their "Function" number.

TL;DR: "Function" = electrical output from decoder | "Button" = physical numbered button on controller

In the case of a sound decoder, which has both LIGHT functions, as well as SOUND functions, there is an added level of complexity. In this case, we like to use the term "OUTPUT" to refer to a lighting function, and the term "FUNCTION" used to refer to sound operations.

All light functions can be remapped or reprogrammed for your desired operation. For more in-depth details on function remapping and output assignment, continue reading below about Function Remapping.

Decoder Wiring Color Code

The NMRA Standard S-9.1.1 defines DCC decoder wiring colors to be as follows:

NMRA DCC Decoder Wire Color Code

Wire Color	[DCC] Function/Application
Red	Right hand (engineer's side) rail power connection. Could also be the center rail in 3-rail applications, or overhead catenary wire
Black	Left hand (fireman's side) rail power connection. Could also be the outside rails in 3-rail applications, or overhead catenary wire
Orange	Positive (+) polarity Motor connection (for "forward" operation)
Grey	Negative (-) polarity Motor connection (for "forward" operation)
Blue	Common positive (+) voltage source for lighting and other options
Black & White (Striped)‡	Common ground (-) for decoder and/or [lighting] functions
White	Function 0 Forward - Forward Headlight
Yellow	Function 0 Reverse - Reverse Headlight
Green	Function 1 (Output 3)
Violet	Function 2 (Output 4)
Brown†	Function 3 (Output 5)
Pink†	Function 4 (Output 6)
Pink & Purple (Striped)†	Function 5 (Output 7)
Green & Brown (Striped)†	Function 6 (Output 8)

NOTE: This is not a complete chart of all wire colors used by TCS on our decoders. The full chart can be found on the page TCS Wire Color Code.

† "Manufacturers may use any colors or other means to identify each wire such as a tag but each wire must be identifiable and this must be documented in the installation instructions. Black, red, orange, gray or blue of the same shade as the power common may only be used as defined in this table" The colors used by TCS to identify these outputs on all decoders are identified here.

‡ "The wire color for "Ground" may be substituted, but must be documented. All efforts must be taken by the decoder manufacturer so as not to confuse the decoder ground with any other input or output."

Wiring Lights to a TCS Decoder

The precise wiring of your locomotive's light functions is ultimately at the discretion of the end user. However, a few rules do apply, and these rules may change depending on the type of light you intend to use. Learn more below!

Lights - The Rules of Wiring Incandescent Bulbs

When using incandescent bulbs, observe the voltage rating - 12V bulbs must be connected to the 12V supply. Incandescent bulbs rated for 1.5V may be connected to 12V, but only through a resistor with appropriate ratings for the rated current of the bulb; alternatively, a TCS VR1.5, or an on-board 1.5V source may be used to provide a regulated 1.5V supply for all of your lights. Some TCS motherboards have dedicated 1.5V power supplies on-board for these bulbs, but not all motherboards. Additionally, some motherboards have dedicated contacts for "Bulbs." These dedicated bulb outputs bypass the on-board resistors for use with LED's which would otherwise prevent the bulb(s) from lighting.

If you are installing an Athearn locomotive of an older vintage which has not had the factory bulbs replaced, you should use the 1.5V power supply as the positive voltage source for your lights. Athearn throughout most of their history has used 1.5V incandescent bulbs, with only a very recent transition to LED's. As such, the 1.5V power supply indicated on the motherboard, plus any correspondingly labeled "Bulb" pads are to be used for these models. The GEN-MB1 and RTR-MB1 motherboards designed for use in the Athearn Genesis and Ready-to-Roll/Blue-Box lines include onboard 1.5V power supplies for this reason.

Incandescent bulbs, unlike LED's, are not polarized, meaning they can be connected with either wire to either pad. It is common for a locomotive manufacturer to bundle together one wire from each light and tie it to the source, then run a single wire from each light to the functions. The same applies to a replacement motherboard. When wiring a TCS motherboard, follow the same practice, connecting one wire from each incandescent light to the appropriate Voltage source, and the second wire from each light must then be run to its own respective function output as described in our Understanding Light Functions section.

Question: "When measuring the voltage for a lighting function, what level should I see?"

When measuring a function output from a decoder or motherboard between a SOURCE (E.G. "Blue" / "12V" / "V+" / etc.) and the output pad, note the following:

• DC Voltage must be selected on your multi-meter
• DC Voltage can only be observed while the decoder is POWERED, and the FUNCTION IS TURNED ON using your throttle.
• The DC Voltage observed will be the voltage developed across the LOAD on the output you are measuring. What is the load, you ask?
  • If no physical lamp is connected to the output you are measuring, your meter IS the load - You will observe the full voltage from the source in this condition.
  • If a physical lamp is connected to the output you are measuring, your meter will read the voltage dropped across that lamp. In the case of an incandescent bulb, this should be the rated voltage.

Question: "My readings are not matching what I expect them to be. What should I do now?"

Visit the Multimeter Troubleshooting section to help diagnose the issue.

Lights - The Rules of Wiring LEDs

When using Light Emitting Diodes (LED's), you must always include a resistor in series with the Cathode to limit current UNLESS your TCS product has on-board LED support. Refer to your decoder literature, wiring diagram, or the silk screen on the board itself for LED connection points (if applicable).

If using Light Emitting Diodes, polarity must be observed, as a reversed connection will not work. Diodes have two connections known as the Anode, which is a (+) connection, and Cathode, a (-) connection. When working with decoders, the Anode(+) connection is to be connected to a common voltage source, and the Cathode(-) connected to an individual function output. These connections will be noted in your decoder literature or on the silk screen of the product itself. The NMRA determined that DCC decoders are to be designed as "Common Anode" devices, meaning there is to be ONE, COMMON, POSITIVE voltage source, and individual returns to ground(-).

BLUE is the color designated by the NMRA to be used for the common Positive Voltage Source. On decoders, this can be designated as a Blue wire, "BL" or "+", or similar. As many lighting functions as needed are to be wired to this one point. Some decoders have multiple connection points for ease of installation. TCS decoders, unless otherwise specified, use an un-regulated +12V DC power supply to power the lighting effects. This power supply is fed directly from the rectified track voltage; therefore, the voltage of this supply will vary based on your track voltage and can be assumed as ~1.5V less than your AC track voltage.

Each function on a decoder is given an associated color and function number to serve as a return to ground. When using LED's, these connections must be made to the cathode (-). If your decoder requires external resistors for use with LED's (not LED-ready), you should always connect the resistor on the cathode (-) side of the LED to prevent current surges into other connected functions as a result of a lighting effect cycle or a function turning on or off.

LED's are current-driven devices, not voltage-driven devices. This means that the voltage across your LED will always remain constant as determined by the LED's voltage rating itself. The brightness of an LED will be determined by the current flowing through the circuit. The current passing through a lighting function is determined by the resistor value used. Following Ohm's Law, we know that the current is directly proportional to the voltage, and inversely proportional to the resistance. If you know the voltage rating of your LED, subtract that from the total voltage in the circuit (we can assume 12V) and divide that value by the resistance to yield your current. All of TCS' LED-ready products (that includes decoders and motherboards) are fitted with 1000 Ohm resistors. This value of resistance yields fine results with just about any LED. If you are using aftermarket LED's, it is recommended that said LED be rated between 1.5V and 6V, with the typical rating being 3V.

Question: "When measuring the voltage for a lighting function, what level should I see?"

When measuring a function output from a decoder or motherboard between a SOURCE (E.G. Blue/12V) and the output pad, note the following:

• DC Voltage must be selected on your multi-meter
• DC Voltage can only be observed while the decoder is POWERED, and the FUNCTION IS TURNED ON using your throttle.
• The DC Voltage observed will be the voltage developed across the LOAD on the output you are measuring. What is the load, you ask?
  • If no physical lamp is connected to the output you are measuring, your meter IS the load - You will observe the full voltage from the source in this condition.
  • If a physical lamp is connected to the output you are measuring, your meter will read the voltage dropped across that lamp. In the case of an LED, this would be 3 Volts in most cases.

Question: "My readings are not matching what I expect them to be. What should I do now?"

Visit the Multimeter Troubleshooting section to help diagnose the issue.

Calculating Resistor Values

Need to calculate a resistor value for your circuit? Make sure you have the voltage and current specs for your lamp, and then click the following link for a handy-dandy tool! [TODO Series Resistance Calculator]

WOWSound - Light Mode and Sound Mode

WOWSound Operational Modes

Question: I hooked up my lights on my WOWSound decoder but I cannot turn them on. What gives?

NOTE: If you are looking for assistance or advice on wiring your locomotive, see our help article: Support - Lighting

NOTE: If you are looking for assistance or advice on programming lighting effects for your locomotive, see our documentation for Lighting Effects

WOWSound decoders have two operational modes: Light Mode and Sound Mode. Whenever a WOWSound decoder powers up, it will default to Sound Mode. In order to access your light functions beyond F0, you must enter Light Mode. (Unless otherwise user-configured.) Keep in mind that a TCS decoder will save the ON/OFF state of the lighting functions through power cycles, meaning it is unlikely that you will need to turn them back on between sessions or power-on-resets.

To toggle operational modes, you must press Button 8 on your controller twice in rapid succession. You will hear an announcement from Audio Assist® announcing the active mode. In order to change back, just press button 8 twice again. If you switch too fast, however, the decoder may register 4 presses and enter the Audio Assist® program.

In sound mode, you can use buttons 0-28 to control sound functions. In Light Mode, you can use buttons 0-12 to control lighting functions. Both modes can be remapped using Audio Assist® or CV programming, but you should refer to your decoder literature for the default mappings. By default, Light Mode buttons will correspond directly to their numbered function output unless otherwise programmed. For more information and guidance on how to remap lighting functions, please refer to our help article on the subject: Support - Lighting

By default, ONLY function 0 will respond to commands in both Sound Mode and Light Mode. In order to use any other function button in both modes, that button must be "dual-enabled" using CV programming. For assistance on CV programming function buttons into dual-mode, visit the Guided Programmer for your decoder type:

Programming Tools

Question: Function 2 doesn't work?

Most likely, lighting Function 2 of your decoder is working. Some command stations and throttles (such as Digitrax) set Button 2 as a momentary function (not latching). You can confirm this by holding the button down to see if your light remains on.

Okay so how do I fix that?

The simple solution is to remap your light to another button. Otherwise, the instruction manual for your throttle or command station should tell you how to change the momentary function to a latching one.

To learn more and see a demonstration of Light Mode and Sound Mode, check out our video on WOWSound Operational Modes:

Dual Enabling Functions

Since some throttles have a limited number of physical function buttons, TCS created "Light Mode" and "Sound Mode" for our WOWSound decoders. This feature allows the user to control many more functions while using the same limited number of buttons. Sound and Light functions can overlap and use the same numbered buttons using this method of operation. While in Light Mode function buttons will control lights, while in Sound Mode the function buttons will control sounds.

The Dual Function feature of WOWSound decoders offers a theoretical 12 additional functions exclusively for lights, in addition to the 28 sound functions. Unlike other decoders, where it is necessary to selectively choose which buttons you need to sacrifice for light functions, the WOWSound Dual Function feature offers a no-compromise solution to throttle control for lights and sounds.

Principle Of Operation

To switch between the modes, press the Audio Assist Button (default is F8) twice in rapid succession and the decoder will announce the mode you are now in. To switch back to the other mode, press the Audio Assist button twice in rapid succession again.

Function Pagination

Some decoders offer additional function pages (if enabled) in addition to Light Mode and Sound Mode - "Function Page 2" and "Function Page 3". This makes it easy to access all 28 functions and all lighting effects on throttles with limited function access by adding an offset to the pressed function button.

On Function Page 2, an offset of +10 is added, meaning pushing F0 is the same as pressing F10, F1 becomes F11, and so on. On Function Page 3, F0 becomes F20, F1 is F21 ... F8 is F28. This feature is useful for command stations that don't support extended functions, such as the Bachmann EZ Command, as it allows users to access all functions even if the command station can't actually send a DCC packet for that function.

NOTE: If a function packet higher then 9 (Button 13 for example) is sent while on a higher function page (2 or 3) the number button pressed will not have an offset. Ergo, Buttons 10-28 always activate Functions 10-28 regardless of the active function page.

Configuration Options and CV's

Dual Enabling Buttons

There are sometimes where you may want both a sound and a light to respond together with a single button press such as pressing F2 to blow the horn and blink the ditch lights, in this case you need the function to be "dual enabled." To dual enable a function button on a WOWSound decoder, you need to configure the Dual Enabled Functions indexed CV 4:14.

1. Begin by programming CV 201 to a value of 4
2. Program CV 202 to a value of 14
3. Use the table below - Select the button(s) to dual enable and program the values into CV 203 and CV 204 accordingly.

TCS Indexed CV 4:14 - "Dual Enabled Functions"

CV204 (Button 0 through Button 6)										CV 203 (Button 7 through Button 12)
Button	0F	0R	1	2	3	4	5	6		Button	7	8	9	10	11	12
Value	1	2	4	8	16	32	64	128		Value	1	2	4	8	16	32

NOTE: In Version 5 decoders, this process was simplified using individual CV's to configure the dual enabled functions from 0 through 28, rather than indexed CV's.

Audible Feedback

The audible feedback for function pagination can be disabled if desired. To do this, you must clear Bit 5 of Indexed CV 4:19, "Sound Options."

Related:

• Light Mode and Sound Mode

Setting Up Lighting Effects

The Lighting Effect CV's are used on decoders to set the lighting effect for each of the lighting outputs. The value in these CV's sets the active lighting effect and the active direction. Consideration must be taken to choose the correct value which includes BOTH factors when performing programming of a lighting effect.

Below, you can find solutions to our most-commonly-asked lighting configuration questions.

Setting up Ditch Lights

Ditch lights are very common on modern Diesel locomotives. Many models available in the market today come factory equipped with at least one pair of operational ditch lights. By default, TCS decoders are configured to output a constantly bright light on all lighting functions. If the road you are modeling has constantly bright ditch lights that simply turn on and off, you can ignore this section. If you are modeling a road which has alternating/blinking/flashing ditch lights, this section below will give you the CV values to program those lights.

Question: How do I turn on my ditch lights on my TCS WOWSound decoder?

Hold your horses! Before we get to turning on the lights, lets make sure they are connected and programmed! To make sure everything is in good working order, let's go through a couple of setup steps. First, TCS recommends connecting your ditch lights to the following lighting outputs - Function 1 & Function 2 for forward, and Function 3 & Function 4 for reverse (if applicable). For instructions on literally hooking up and wiring your lighting functions to a TCS decoder or motherboard, read the sections above for Wiring Lights to a TCS Decoder with either LED's or Incandescent Lamps.

Once you have your ditch lights physically connected, we can get down to programming! The easiest way to set up your ditch lights is by using TCS' quick preset for ditch lights. Most users want their ditch lights to flash if the Horn button is pressed. By using this preset, a WOWSound decoder will operate in this way. The quick preset will automatically perform the following sequence. You do NOT need to manually enter this sequence unless something goes wrong.

STANDARD CONFIGURATION: Two Omni-Directional Ditch Lights Controlled by Button 1

To set up GREEN and VIOLET: (Turn on/off with Button 1 [in light mode for sound decoders])

• CV35 = 4 - Function 1 on/off with Button 1
• CV36 = 4 - Function 2 on/off with Button 1
• CV51 = 42 - Ditch Light Side 1 (Bi-Directional)
• CV52 = 43 - Ditch Light Side 2 (Bi-Directional)
• CV124 = 8 - BLINK ON BUTTON 2 ONLY

FOR SOUND DECODERS, To set up Button (2) to work in both light & sound mode, program the following sequence in order:

• CV201 = 4
• CV202 = 14
• CV203 = 2
• CV204 = 11 - DUAL ENABLE BUTTON 2

NOTE: All of the above configurations will be set automatically if you use the CV 8 Macro for Ditch Lights. The ditch lights will turn on and off using Button 1 (in Light Mode for sound decoders) and will not turn off in the reverse direction.

ADVANCED CONFIGURATION: Four Directional Ditch Lights Controlled by Button 1

For models which have four ditch lights - one pair in the front and one pair in the rear, the above sequence needs to be modified. For example, the lights may need to be set to be directional. To set this up, use the following programing steps:

To set up GREEN and VIOLET: (Turn on/off with Button 1 [in light mode for sound decoders])

• CV35 = 4 - Function 1 on/off with Button 1
• CV36 = 4 - Function 2 on/off with Button 1
• CV51 = 10 - FWD-ONLY DITCH LIGHT
• CV52 = 11 - same as above
• CV124 = 8 - BLINK ON BUTTON 2

To set up PINK and BROWN: (Turn on/off with Button 1)

• CV39 = 4 - Function 3 on/off with Button 1
• CV40 = 4 - Function 4 on/off with Button 1
• CV53 = 26 - REV-ONLY DITCH LIGHT
• CV54 = 27 - same as above

FOR SOUND DECODERS, To set up Button 2 to work in both light & sound mode, program the following sequence in order (If you programmed CV8 to 10 already, you do not need to program the following!):

• CV201 = 4
• CV202 = 14
• CV203 = 2
• CV204 = 11
  

Modification to Use Button 0 (Headlight)

If you would like to have your ditch lights operate on Function 0 (headlight) rather than Function 1 in light mode, set the following during or after the previous sequence:

• CV35 = 1
• CV36 = 1
• CV39 = 1
• CV40 = 1
  

Modification to Allow All Horn Sounds to Blink Ditch Lights (WOWSound Version 4 and Older)

TCS WOWSound decoders offer 3 horn/whistle buttons by default on Buttons 2, 3, and 4. If you would like to set up the ditch lights to operate when ANY of those buttons are pressed, you need to modify the sequence(s) above with the values below during or after the previous sequences:

• CV124 = 56 - Blink Ditch lights on Button 2 OR 3 OR 4.
• CV201 = 4
• CV202 = 14
• CV203 = 2
• CV204 = 59 - Dual-enable Buttons 2, 3, and 4

Now that we have completed our programming, we can turn the lights on! If you have configured your ditch lights to operate with the headlight, just turn your headlight on and you are done! If you have a TCS WOWSound decoder and have programmed your ditch lights to a different function button, you need to go into Light Mode.

Setting up Directional Marker Lights

Question: How do I set up directional marker lights on my passenger service locomotives?

By default, (with exceptions in the OEM market of course) the default lighting effect for Function 1 and up is "Constant Bright" in both directions. This means that if you turn on a lighting function number 1 or greater, it will come on at full brightness, and will remain that way in either direction until you turn it back off. A common request we receive is to set up marker lights that are active in the opposite direction of travel. The directionality of lighting effects is based on the value entered in for that lighting effect generator. The Lighting Effect CV's can be programmed with values to determine the lighting effect as well as the direction of that lighting effect. For example, a constant bright light in the forward direction equates to a value of 0; in the reverse direction, this value is 16, and for both directions (the default value) is 32.

For the above case, light functions tied to the lights physically pointing opposite the direction of travel need to be programmed with the value which corresponds to the direction of travel. For example, the lights on the rear of the engine would be programmed to be ON in forward, and the lights on the front of the engine would be programmed to be ON in reverse.

Please consult the Full List of Lighting Effects for your decoder type and version for the full chart of available lighting effects and the corresponding directional values.

Setting up "Constant Dim" Lighting Effects

The "Constant Dim" lighting effect is useful in applications where you may not want to have a lighting function be active at full brightness at any time. Examples may include passenger car lighting, directional markers, a cab light, or plenty of other circumstances. In order to use and customize the "Constant Dim" lighting generators, you need to do two things:

1. Assign a Constant Dim lighting generator to a Function Output.
2. Configure the Constant Dim generator to your desired brightness level (optional)

The exact performance of a constant dim lighting effect will vary based on factors such as:

• The rated voltage of the lamp (LED or incandescent)
• The series resistance (if applicable)
• The output capacitance (if applicable)

It is recommended to use a capacitor in parallel with your LED lights when using the constant dim lighting effect if you intend to take videos of your models. Photosensors on cameras will often pick up on the PWM when using LED's and the constant dim lighting effect, resulting in a flicker on the video. This same flicker is not visible to the naked eye, and is as such not normally an issue. This issue is also not typically a problem if you use incandescent bulbs.

WOWSound Version 4 (and older) and TCS Non-sound

Note that in TCS WOWSound Version 4 (and older) decoders, as well as the non-sound product line, we offer FOUR independent dimness generators. Any lighting output can be assigned to have its own "dimness" generator assigned, or the same generator may be assigned to multiple functions simultaneously depending on your needs. By applying the same dimness generator to multiple lighting effects, those lighting effects will operate at the same level of dimness relative to the configurable setpoint.

Step 1: To assign a constant dim lighting effect to an output, program the Lighting Effect CV for that output using the corresponding value found in the Full List of Lighting Effects based on the generator number and active direction you desire.

Step 2 (optional): Each of the constant dim generators can be individually reconfigured using individual CV's. Program the corresponding "dimness level" CV for the generator you selected to change the level of dimness.

Note: There are also two other "dimness" generators for use in Rule 17 applications, allowing you to independently configure the dimness level of both headlights in addition to the four constant dim generators. The chart below shows all of the CV numbers and corresponding generator numbers which you can configure.

Constant Dim Lighting Effect Configuration

CV Number	Dim Generator	CV Range	Default
CV 156	FWD Headlight	1-30	1
CV 157	REV Headlight	1-30	1
CV 64	Constant Dim 1	1-30	6
CV 153	Constant Dim 2	1-30	5
CV 154	Constant Dim 3	1-30	5
CV 155	Constant Dim 4	1-30	5

WOWSound Version 5

Coming Soon!

Setting Up Rule 17

Rule 17 (known in modern times as Rule 5.9.1-5.9.4) is a prototype railroad rule which defines the behavior of the brightness of lights on locomotives, particularly in regards to the direction of a locomotive and its proximity to other trains. The exact behavior and rules can vary slightly on a per-railroad basis, and has been applied in different ways in the past. For locomotives which feature headlights on both ends, there have been different control methods throughout history for selecting the direction and brightness of the headlights.

In a TCS decoder, any lighting output can be configured as a "Rule 17 Dimmable" lighting effect, not just the typical "headlight" outputs of F0F and F0R. This is allowed for cases where the installation makes use of more than a single lamp for a single directional headlight, and also allows for applications where additional lights on the locomotive may be dimmed. For instructions on literally hooking up and wiring your lighting functions to a TCS decoder or motherboard, read the sections above for Wiring Lights to a TCS Decoder with either LED's or Incandescent Lamps.

Just as with typical headlights, the Rule 17 Dimmable lighting effect allows for specification of which direction that light will be "On" in - Forward, Reverse, or Both Directions.

• If set to "forward," that light will only come on in forward, and will dim as necessary while in forward.
• If set to "reverse," that light will only come on in reverse, and will dim as necessary while in reverse.
• If set to "both directions," that light can be on in either direction, and will dim as necessary. The light will only turn off when turned off using the button it is mapped to.

Automatic Rule 17 Features

In a TCS decoder, there are a few settings which allow you to configure automatic behavior for lighting outputs programmed with the Rule 17 Dimmable lighting effect. These settings are enabled and disabled through CV 61 and are described in detail below:

Automatic Dim When Stopped

CV 61, Bit 4 (Value of 16) - If this setting is enabled, all Rule17 Dimmable lighting outputs active in the current direction of travel will dim when the locomotive is stopped.

Automatic Opposite Dim

CV 61, Bit 4 (Value of 32) - If this setting is enabled, all Rule17 Dimmable lighting outputs active in the opposite direction of travel will dim automatically when the direction changes.

Automatic Dim When Stopped & Opposite Dim

It is possible to have both automatic Rule 17 options active at the same time.

Rule 17 Dimmable lights will operate in accordance with the truth tables below:

Throttle Direction Set to FORWARD

		F0F	F0R	F0F	F0R	F0F	F0R
		Forward	Reverse	Both	Reverse	Both	Both
Opp. Dim	No	Bright	OFF	Bright	OFF	Bright	OFF
Dim w Stop	No
Opp. Dim	Yes	Bright	OFF	Bright	OFF	Bright	Dim
Dim w Stop	No
Opp. Dim	Yes	Bright only if moving	OFF	Bright only if moving	OFF	Bright only if moving	Dim
Dim w Stop	Yes
Opp. Dim	No	Bright only if moving	OFF	Bright only if moving	OFF	Bright only if moving	OFF
Dim w Stop	Yes

Throttle Direction Set to REVERSE

		F0F	F0R	F0F	F0R	F0F	F0R
		Forward	Reverse	Both	Reverse	Both	Both
Opp. Dim	No	OFF	Bright	OFF	Bright	OFF	Bright
Dim w Stop	No
Opp. Dim	Yes	OFF	Bright	Dim	Bright	Dim	Bright
Dim w Stop	No
Opp. Dim	Yes	OFF	Bright only if moving	Dim	Bright only if moving	Dim	Bright only if moving
Dim w Stop	Yes
Opp. Dim	No	OFF	Bright only if moving	OFF	Bright only if moving	OFF	Bright only if moving
Dim w Stop	Yes

Manual Rule 17 Dimming

A manual "dimmer switch" is available for the operator to dim the light(s) at any time. The button which operates this manual dimmer switch is configurable using Function Remapping. For most decoders, the default manual dimmer button is 4. A good example of when you may want to use the manual dimmer switch is when approaching another train head-on, (as directed in rule 5.9.1-5)

Regardless of whether or not the Automatic Rule17 Features are in use, the manual dimmer will dim ALL Rule 17 Dimmable lighting outputs when pressed On. Press again to turn the manual dimmer Off and brighten the lights. If the automatic Rune 17 features are in use, the manual dimmer button will override all automatic dimming.

Function Remapping

Overview - Function Remapping

NOTE: This section only covers the remapping of LIGHT functions, not SOUND functions.

Function mapping of lighting outputs can be done via the programming of Configuration Variables or via Audio Assist on WOWSound decoders. Your decoder literature pamphlet, as well as the programming resources available on this site will show the CV's and values that correspond to the function outputs and function buttons.

In the NMRA Standards document S-9.2.1 (currently under revision), the DCC standard for packet transmission (that is, the communication over the rails), function buttons for lighting are separated out into three function groups. Functions 0-4 make up the first group within the packet, and Functions 7-12 are part of Group 2. Group 2 is further divided into Lower and Upper groups, with Function 5 though Function 8 making up Lower Group 2, and Function 9 through Function 12 making up Upper Group 2. Note that in this context, the word "Function" is being used to refer to button numbers used to control the decoder, not actual output from the decoder.

Function Remapping - TCS Non-sound Decoders; WOWSound Version 4 and Older

In TCS non-sound decoders, as well as WOWSound Version 4 hardware and older, if a function is going to be assigned to respond to a command in one of these groups, it needs to be configured in that corresponding CV. Below is a chart identifying the CV numbers and corresponding values used to map a lighting function to a button number.

Function Remapping

Group A (Button 0 through Button 6)										Group B (Button 7 through Button 12)
Button	0F	0R	1	2	3	4	5	6		Button	7	8	9	10	11	12
Value	1	2	4	8	16	32	64	128		Value	4	8	16	32	64	128
Use values for buttons from above to program CV numbers for function outputs below A value of 0 removes control of that output from any button within the group. Functions 0F & 0R cannot be remapped above Button 6 in decoders of the defined types (above) which use this chart.
CV	Output No.			Default						CV	Output No.			Default
33	F0 FWD			1
34	F0 REV			2
35	F1			4						37	F1			0
36	F2			8						38	F2			0
39	F3			16						41	F3			0
40	F4			32						42	F4			0
43	F5			64						45	F5			0
44	F6			128						46	F6			0
123	Rule 17 Dimmer			32						158	Rule 17 Dimmer			0
124	Blink Ditch Lights			8						159	Blink Ditch Lights			0

As you see on the chart, Functions 1 - 6 have TWO CV's EACH. The CV on the LEFT of the chart can be used to assign a button from 0 - 6 to that function. A value of ZERO in any of these CV's will disable the function from responding to any button from 0 - 6. Along the RIGHT of the chart are the secondary CV's which correspond to buttons 7-12. By default, these CV's are 0. By programming a value to these CV's, a button or buttons can be assigned to activate the function from 7-12. Note that it is possible to have multiple buttons control the same function using this method if desired. It is suggested that only one CV for each function be programmed with a non-0 value to prevent de-synchronization or confusion.

Along the TOP of the chart are two sections with values from 1 to 128. The numbers from 0 to 12 listed above the values state what value would correspond to that button number. By programming the value listed below a button number, that button will be assigned the function whose CV was just programmed.

It is important to know the difference between a FUNCTION and a BUTTON.

• A FUNCTION corresponds to a numbered function output and/or colored wire from the decoder. For details on which color of wire corresponds to a numbered function output, refer to the chart above, or the NMRA Wires and Connector Standards.
• A BUTTON is located on your throttle or control device and does not necessarily directly correspond to any output from the decoder, as this can be configured.

Example: You are attempting to move a function to the higher function group. F2 -> Button 8. To do this, once again look at the chart. Function 2 has two CV's - CV36 and CV38. Button 8 is part of the higher functions, which would make use of CV38. Therefore, by selecting the value that corresponds to Button 8 (a value of 8), and programming that value into CV 38, Function 2 will now respond to Button 8. To finish the transfer, we need to clear the button from responding to Button 2. To do this, program CV 36 with 0. Now you are finished!

Function Remapping - WOWSound Version 5

(COMING SOON!)

Available Lighting Effects

This table below contains a list of all of the lighting effects available on TCS Non-sound decoders of recent production (2012 or newer) and WOWSound Version 4 decoders. If your decoder is older than 2012 or Version 4, some of the items may not apply.

These lighting effects can be used in conjunction with the Function Remapping instructions. You can also consult our Support Page for Decoder Lighting for more information.

Lighting Effects (WOWSound V4 & Non-Sound V88+)

Lighting Effect	Forward	Reverse	Both Dir.	Description
Auto Mars Light	13	29	45	The Auto Mars light has a light pattern like a "sideways number 8" (∞ pattern) when in a certain speed range.
Brake Lights	14	30	46	Brake Lights come on when the Brake Button is pressed. They can be configured to be On/Off or On/Dim using CV 61.
Constant Bright Light	0	16	32	Constant Bright Light is a standard lighting feature which turns On or Off with the push of a button.
Constant Dim (1)	12	28	44	Constant Dim Lights can be used to turn down the brightness of lights (such as Number Boards) without having to add in additional resistance to drop the voltage or brightness. Constant Dim outputs can also be used to drive other devices such as relays, small motors, etc. where the power needed is less than maximum the output can provide. Each Constant Dim lighting effect can be individually adjusted for multiple applications while using the same decoder.
Constant Dim (2)	66	82	98
Constant Dim (3)	67	83	99
Constant Dim (4)	68	84	100
Ditch Light Side A	10	26	42	Ditch Lights are lights installed in pairs on the front and/or back of a locomotive. Some railroads require these lights to flash in an alternating pattern in certain conditions, such as when the horn blows. See Setting Up Ditch Lights for more info.
Ditch Light Side B	11	27	43
Double Pulse Strobe 1	5	21	37	An intermittent strobe light which pulses twice rapidly at a specified interval.
Double Pulse Strobe 2	64	80	96	An intermittent strobe light which pulses twice rapidly at a specified interval.
Flashing Light	3	19	35	An intermittent light output which turns on and off with a specified frequency. Example: E.O.T./F.R.E.D. devices.
Gyra Light	7	23	39	Gyra Lights were used as a warning device on locomotives and have a distinct movement pattern.
Mars Light	2	18	34	Same as the Auto Mars effect, but does not automatically shut off after reaching a set speed.
Random Flicker (1)	1	17	33	The Random Flicker lighting effect can be used to simulate the light emitted by fire, such as in a steam locomotive firebox.
Random Flicker (2)	65	81	97	Can be combined with Random Flicker 1 to add more randomness, or additional colors for your firebox flame.
Rotary Beacon	6	22	38	Simulates a light which has a rotating reflective shield inside which directs and blocks light while it spins.
Rule 17 Dimmable	8	24	40	(AKA Rule 5.9.1-5.9.4) specifies operational instances where lights should be dimmed. See Setting Up Rule 17 for more info.
Single Pulse Strobe (1)	4	20	36	An intermittent strobe light which pulses once at a specified interval.
Single Pulse Strobe (2)	15	31	47	An intermittent strobe light which pulses once at a specified interval.
Disable Output*	255			*Using a value of 255 in the lighting effect CV will disable the output from coming on for any reason.

Use a single value from one of the three columns on the right to program a Lighting Effect CV. The value chosen will select the Lighting Effect and Direction the light will be active in. For example, a value of 80 programmed into CV 51 will set up the Double Pulse Strobe effect when Lighting Function 1 when the function is ON and the locomotive is in Reverse.

Lighting Effect CV's

The CV's listed in the table below will configure the Lighting Effect for the specified Lighting Output.

Lighting Effect CV's (WOWSound V4 & Non-Sound V88+)

Lighting Output	CV to Program
Function 0 Forward	CV 49
Function 0 Reverse	CV 50
Function 1	CV 51
Function 2	CV 52
Function 3	CV 53
Function 4	CV 54
Function 5	CV 55*
Function 6	CV 58*
Function 7	Not supported
Function 8	Not supported

Program a value from the previous table into the CV listed in this table to apply a Lighting Effect to that Lighting Output. Not all of these lighting function outputs and corresponding CV's are supported on all decoders. Check your decoder literature or the product page on our website to verify the maximum number of lighting function outputs your decoder supports.

*The CV's marked may not be supported on specific decoders. While these outputs may be present, they may not support mapping of lighting effects and are ON/OFF only. Check your decoder literature - If these CV's are not listed in the literature, they are not supported by the decoder.

IMPORTANT NOTE: The Lighting Effects set up using the tables above are tied to the Lighting Output and NOT the Button number. Lighting Outputs and numbered buttons are completely different things. See our Support Article for Lighting for more information.

Lighting Effects on DC Power

On DC power, a TCS decoder (with DC mode enabled in CV 29) will operate all of the lighting outputs which have been enabled in CV 13 and CV 14. Each enabled output will also output the lighting effect it has been configured for, as described above. Ergo, a lights such as strobes, rotary beacons, mars lights, etc. will operate on a DC track just as they would on a DCC track, including direction-ally.

Support - Lighting

DC Mode Lights F1-F8 Range of Values 0-255 Accepted Values 0-255 Default Value 255

NMRA CV 13 - DC Mode Function Status F1-F8

CV 13 configures the active/inactive status for each lighting function output (F1 through F8) when the unit is operating in alternate power (DC) mode, which cannot control the functions. If a function cannot be controlled, then the corresponding bit is ignored.

If the bit for a function output is "cleared," this indicates the function is disabled on DC power. If the bit for a function output is "set," this indicates the function output is enabled on DC power. This configuration affects the physical outputs on the decoder, not the button numbers! If you have remapped a lighting output to a different button, that will not affect this configuration. Note also that you must set up this CV to use the correct lighting outputs, not button numbers.

NOTE: If a lighting output has been programmed with a lighting effect, such as a Mars light, that feature will continue to operate while on DC power.

CV 13 is a bitwise CV, where each bit corresponds to a different setting/feature. Bit 0 corresponds to F1, while Bit 7 corresponds to F8. See the chart below:

CV13 - DC Mode Lights
Bit	Feature	Value	Default
0	Function 1	1	ON
1	Function 2	2	ON
2	Function 3	4	ON
3	Function 4	8	ON
4	Function 5	16	ON
5	Function 6	32	ON
6	Function 7	64	ON
7	Function 8	128	ON

The SUM of the desired functions active while operating in DC mode must be programmed into CV 13. A value of 255 enables all light functions on DC power.

Support - Lighting

DC Mode Lights F0 & F9-F12 Range of Values 0-63 Accepted Values 0-255 Default Value 255

NMRA CV 14 - Alternate Mode Function Status F9-F12

CV 14 configures the active/inactive status for each lighting function output (F9 through F12, & FL) when the unit is operating in alternate power (DC) mode, which cannot control the functions. If a function cannot be controlled, then the corresponding bit is ignored.

If the bit for a function output is "cleared," this indicates the function is disabled on DC power. If the bit for a function output is "set," this indicates the function output is enabled on DC power. This configuration affects the physical outputs on the decoder, not the button numbers! If you have remapped a lighting output to a different button, that will not affect this configuration. Note also that you must set up this CV to use the correct lighting outputs, not button numbers.

NOTE: If a lighting output has been programmed with a lighting effect, such as a Mars light, that feature will continue to operate while on DC power.

CV 14 is a bitwise CV, where F0 in the forward direction is controlled by bit 0, F0 in the reverse direction is controlled by bit 1, bit 2 corresponds to F9, and Bit 5 corresponds to F12. See the chart below:

CV14 - DC Mode Lights
Bit	Feature	Value	Default
0	Function 0 FWD	1	ON
1	Function 0 REV	2	ON
2	Function 9	4	ON
3	Function 10	8	ON
4	Function 11	16	ON
5	Function 12	32	ON

The SUM of the desired functions active while operating in DC mode must be programmed into CV 14. A value of 255 enables all light functions on DC power.

Consist Lighting Effects Configuration

When the decoder is in a CV 19 consist, the available function buttons can be enabled and disabled. For non-sound decoders, disabling a button number will disable any lighting effects tied to that function button. For WOWSound decoders, these CV's will disable sound functions in Sound Mode, and light functions in Light Mode.

Support - Lighting

Consist Light Control (F1-F8) Range of Values 0-255 Accepted Values 0-255 Default Value 0

NMRA CV 21 - Consist Lighting Control for Function 1 Through Function 8

This CV is used to configure what functions will respond to user input on the consist address. This particular CV affects F1-F8. For each Bit which is set, that the function will respond to instructions addressed to the consist address ONLY. Each bit which is cleared indicates that the function will only respond to instructions addressed to the locomotive's individual address. F1 is controlled by bit 0; F8 by bit 7.

To determine which functions are active, use the table below and combine the values of the functions you would like to have active, and program the sum into CV 21. By default, all functions are active on the consist address.

NOTE: WOWSound decoders prior to Version 5 and all non-sound decoders will always have all functions available on the Base Address. This CV, as well as CV 22 can be used only to deny the use of a function while in a consist when the consist address is selected.

Bit	Feature	Value	Default
0	Function 1	1	Control on Base Address
1	Function 2	2	Control on Base Address
2	Function 3	4	Control on Base Address
3	Function 4	8	Control on Base Address
4	Function 5	16	Control on Base Address
5	Function 6	32	Control on Base Address
6	Function 7	64	Control on Base Address
7	Function 8	128	Control on Base Address

Related:

• Consist Address
• Consist Lighting (Part 2)
• Consist Acceleration Adjustment
• Consist Deceleration Adjustment
• Dual Prime Mover Delay

Support - Lighting

Consist Light Ctrl. (F0, F9-F12) Range of Values 0-63 Accepted Values 0-255 Default Value 0

NMRA CV 22 - Consist Lighting Control for Function 0 and Function 9 through Function 12

This CV is used to configure what functions will respond to user input on the Consist Address. This particular CV affects F0 and F9-F12. For each Bit which is set, that function will respond to instructions addressed to the consist address. Each bit which is cleared indicates that the function will only respond to instructions addressed to the locomotive's base address. F0F is controlled by Bit 0, F0R by Bit 1, F9 by Bit 2, and F12 by Bit 5.

To determine which functions are active, use the table below and combine the values of the functions you would like to have active, and program the sum into CV22.

Bit	Feature	Value	Default
0	Function 0 Forward	1	Control on Base Address
1	Function 0 Reverse	2	Control on Base Address
2	Function 9	4	Control on Base Address
3	Function 10	8	Control on Base Address
4	Function 11	16	Control on Base Address
5	Function 12	32	Control on Base Address

Related:

• Consist Address
• Consist Lighting (Part 1)
• Consist Acceleration Adjustment
• Consist Deceleration Adjustment