What is the difference between F1 and F2 Modes? Current USA - Support February 07, 2014 05:48 Updated Follow F1 = 15 minute ramp up/15 minute dim down F2 = Instant on/off Related articles What is the recommended schedule for turning lights on and off? Can I plug the Single Ramp Timer into an inline dimmer? Product Downloads - Manuals & Instructions What type of coral can the Orbit IC support? How do I program the Single Ramp Timer? Comments 0 comments Please sign in to leave a comment.