The vs0401 4 port vga switch with audio allows you to connect four audiovideo source computers to a single monitor or projector with full audio and quickly switch between the devices for use vs0401 features built in bi directional rs 232 serial port for high end system control and advanced rs 232 control with the ability to use high end serial control devices via rs 232 commands allows the vs0401 to be controlled by secondary systems with advanced functions such as port switching auto s