Hall Research VS-2A - Manual (Page 6)

4
Model VS-2A
. Connection Diagram
4.0 Operation
. Switched Output
The switched output SELECT button is used to select between video &
audio input sources of PC 1 and PC 2. A solid-on LED is used to indicate
which input is selected.
Holding down the switched output SELECT button for 3 seconds will
blank the current selected input source (and mute the audio output). The
LED for the current selected input will start blinking to indicate the
blanking mode. Pressing the SELECT button again will un-blank the
output and un-mute the audio on the switched out.