The LED signal indicator (RX), located on the front right side of a Receiver Switch unit below the antenna, provides a visual indicator of its current operating status.
Green LED
Flashes each time a transmitted signal is received by the Receiver Switch from the Transmitter at its update time.
Will flash for 60 minutes when it has received a valid time update
Will remain solid for 60 minutes if it has NOT received a valid time update.
Yellow LED
Continues to flash if the unit goes 48 hours without receiving a time update.