Keyboard video mouse switch for multiple chaining and a method for switching electrical signals thereof

A keyboard, video, mouse (KVM) switch, suitable for a plurality of signal output devices sharing a plurality of signal input devices by a plurality of KVM switches, the KVM switch comprising:

• a chain switching array having a plurality of chain input ports, a plurality of first chain output ports and a plurality of second chain output ports, wherein the chain input ports are connected to other second chain output ports of another first KVM switch, the first chain output ports are connected to the signal input devices, and the second chain output ports are connected to other chain input ports of another second KVM switch;
• and
• a local switching array having a plurality of local input ports, a plurality of first local output ports and a plurality of second local output ports, wherein the local input ports are connected to the signal output devices, the first local output ports are connected to the signal input devices, and the second local output ports are connected to the other chain input ports of the second KVM switch;
• wherein when destinations of the first chain output port and the first local output port are the same, the first chain output port and the first local output port are not allowed to transmit simultaneously, and when destinations of the second chain output port and the second local output port are the same, the second chain output port and the second local output port are not allowed to transmit simultaneously.