System and methods for reducing redundant messages broadcast in an Automatic Dependent Surveillance-Broadcast system. The bus comprises an IMB slave CPU, at least two registers, and a three bit data connector, which connects the two registers. The optically switchable device includes electrodes. The passageway of one of the spool or the housing includes a first groove which extends parallel to the axis, but not substantially about said one of the spool or the housing. A delay locked loop is provided in the secondary side switch controller that turns on the catch transistor when the power switch is turned off and turns off the catch transistor at a predetermined time before the power switch is turned on.