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.