The D-RC4RU is a wall-box mounted remote module designed to directly control an RDL RU-SX4A Audio Switcher Module. The RU-SX4A provides solid state switching of one of four balanced/unbalanced audio inputs to a single balanced/ unbalanced audio output. The D-RC4RU connects directly to the power and SLAVE terminals of the RU-SX4A using a 3-pair cable (or a 6-conductor cable). The D-RC4RU may be used to directly control the RDL RU-VSX4 Video Switcher.

The front panel of the D-RC4RU features four pushbuttons with four associated LEDs. Upon initial application of power, source 1 is selected. Touching any of the other 3 buttons de-selects source 1 and immediately selects the source corresponding to the button pushed. An LED adjacent to each button shows which source is selected. There are 4 output terminals on the D-RC4RU. Each of these is an open-collector output, which is pulled to ground when the output is selected. For stereo installations, the D-RC4RU is capable of driving two RU-SX4As simultaneously.