Our initial locomotive lighting control was either On or Off. In an upcoming software release you will now have the ability to change between On/Off, Flash, MARS/Gyrolite and Rule 19 lighting modes. On/Off was preserved from prior releases. Flash alternates the light between On and Off with a brief time delay. MARS/Gyrolite pulsates or adds a "breathing" effect - really smooth. Finally, Rule 19 quickly dims the light so oncoming locomotive engineers aren't blinded by the light.