This pane provides for control of some of the most "gee-whiz" functions on the decoder. While fine-tuning the motor is important, and speed tables help add to the realism of operation, everyone notices the lights - especially when they change intensity, flicker, flash, or fade. They attract even more attention when, for example, the ditch lights that were steadily shining as the locomotive approached the crossing suddenly begin flashing alternately, then return to a steady glow; or when a locomotive pulls into a siding, stops, and dims its headlight for the approaching train.
The specific effects available differ widely between manufacturers, and even between different "families" of decoders from the same maker. The above example is from a Digitrax FX decoder. Some of the advanced features you will see in many decoders (though they may go by different but similar names) are Lamp keep-alive voltage, FX rate adjust, and Ditch light hold-over time.
The Lamp keep-alive voltage determines how dark a light gets between "full on" moments. This can let you adjust effects to give the impression of, for example, a marker light that also has a rotary beacon in the same housing. Play with this value and see what kind of results you get for your specific decoder.
FX rate adjust controls how fast an FX effect operates. The higher the number, the slower the frequency of flash or "rotation" of the effect. I use this to set subtle differences between my locomotives. As you can see from the panel above, I use twin alternating strobe lights on my engines. I vary the setting for the FX Rate slightly so that my locomotives flash at slightly different rates. This keeps MU'd units from looking too coordinated!
The Ditch light hold-over time CV establishes how long the ditchlight effect (alternating flashing) stays activated after you hit the F2 function key. Since the F2 key is non-latching (think of it as a momentary contact switch) it normally turns off when it is released. By raising the value of this CV you can make them stay on for up to 30 seconds from a single momentary activation.
The other lighting effects are highly variable between decoders. Check your specific decoder documentation for what the decoder is supposed to be capable of doing, and have fun playing with them. They are the most visually satisfying of all the capabilities of the decoders!
