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 When the programmed “on” time is reached, my light doesn’t ramp up but immediately goes to full brightness How do I program the Dual Ramp Timer? When I plug my LED lights into the timer, they blink on and off What is the recommended schedule for turning lights on and off? Can I plug the Single Ramp Timer into an inline splitter? Comments 0 comments Please sign in to leave a comment.