FX Lighting allows you to simulate many lighting effects used on real railroads: Mars light, Gyralite, Rotary Beacon, Ditch Lights that blink when you press the horn button, and more.

FX is a term coined by Digitrax when they came out with their first special lighting effects decoders. But this type of lighting effects was not new at that time. Throttle Up! came out with a product called HyperLights (now discontinued) years earlier . HyperLights allowed you to install Mars and other special lighting effects on DC analog locos. While it worked, you just didn't have the on-the-fly on/off control like you have with DCC and they wouldn't work unless the track had voltage to make the loco go.

For about the same price you would have paid for HyperLights, you can buy a decoder that controls the loco's speed, direction, and lights ­ not only being able to turn the lights on and off any time you want (even when the loco is stopped), but you have the option to program them to any one of many different special effects.

Even though Throttle Up! was the first company to produce special lighting effects, it was Digitrax that put it on the map, calling it FX Lighting. Therefore, many companies that produce decoders with special lighting effects also call them FX or something similar. HyperLights still exist in many of Throttle Up!'s sound decoders, and are advertised as HyperLights.

The most extraordinary thing about FX Lighting effects is that they can all (except for Blinking Ditch Lights) be simulated with a single incandescent bulb. It will work with LEDs, but not quite as well. These effects are produced by manipulating the amount of voltage for the bulb to use. The more voltage for the bulb, the brighter the bulb will be. The less voltage for the bulb, the dimmer the bulb will be. By carefully controlling how fast the voltage ramps up and down, and how far up and down it ramps, the single bulb can amazingly simulate how a Mars light, Gyralite, Rotary beacon, or other light looks.

Let's take the Mars light for example. When looking at a real one head on, it appears to get really bright, then dim, then a little bit bright, then dim, then repeat the process over and over. To simulate this with a single 14-volt bulb (with HO scale, function outputs typically get a maximum of between 13 and 14 volts), the voltage would reach about 13 volts, then ramp down to about 6 volts, then back up to about 10 volts, then down to 6 volts, then back up to 13 volts to start the whole process over again.

The speed with which the voltage ramps up and down plays a big part in making the simulation realistic. Because of this, there is usually a CV to control the speed with which it works. This way any road's Mars light, Gyralite, Rotary Beacon, etc., can be simulated. These simulations are so amazingly realistic, many people abandon Life-Like's Mars light so they can use the FX Mars light instead.

Following is a complete list of Digitrax's FX simulations:

Random flicker (for steam fireboxes)
Mars light
Flashing Headlight
Single-pulse strobe
Double-pulse strobe
Rotary beacon
Gyralite
Rule 17 dimmable headlight (dims when Function 4 is turned on or loco direction is opposite)
FRED
Blinking Ditch Lights (starts blinking when Function 2 [the horn button] is pressed)

Various other companies pretty much provide the same list of effects. However, there are some variations. For example, Throttle Up! has two different types of Blinking Ditch Lights: one stops the blinking to the off state, the other stops the blinking to the on state.

Most of Digitrax's decoders have special effects. However, the ones ending with "2" generally do not produce properly timed Blinking Ditch Lights. The rest of the effects are OK so far as I know.

All of Train Control Systems' decoders have special effects. However, decoders with only two functions are limited as to what effects they offer - it doesn't make sense to offer Blinking Ditch Lights when that takes two functions by itself (no functions left for the headlight).

Most soundTraxx LC sound decoders have HyperLights, but having only two functions, they are naturally limited as to what can be done. There is at least one LC that has more than two functions, so check the LC sound decoder listing for more information. DSX has no light functions at all.

FX Lighting features usually reside in CV 49 and up. You'll need a system or other method to program those CVs with any number of values.

All of Digitrax's current systems can program any value into these CVs.

Once configured, lighting effects will work on any system that is capable of turning the function on. Not only that, with DC Analog Function Control, the special effect will even operate on a DC Analog layout once the track voltage is high enough to make it work. Digitrax decoders have this feature, Train Control Systems do not, and Throttle Up! SoundTraxx decoders won't work on analog at all.

All of Digitrax's current systems can control any function that the throttle can access. The DT200 and BT2 throttles can control functions 0 through 4, the UT1 and UT2 throttles can control functions 0 through 5, the DT100 and DT300 throttles can control 0 through 8, and the DT400 can control 0 through 12.

FX Lighting is not intrusive. You do not need to bother with it unless you want to use it.