xantech sr21 remote a b speaker relay module
the sr21 is an ir remote controlled a b speaker relay module . it allows the installer and user to switch the output of one stereo amplifier between two speaker pairs or to switch one speaker pair between the outputs of two stereo amplifiers . the switching is accomplished by way of infrared commands originating from a xantech rc68 or rc68 programmer . it can also be switched by a dc voltage applied between the ci control input and gnd terminals . the rc68 commands are taught to learning devices and passed to the ir in and gnd input terminals of the sr21 via xantech ir receivers keypads and connecting blocks .