SERIAL PORT REMOTE CONTROL CIRCUIT

A serial port remote control circuit includes a first interface circuit, a control circuit, an output circuit, and a power circuit. The first interface circuit converts recommended standard 232 (RS232) level signals to transistor-transistor logic (TTL) level signals or vice versa. The control circuit is connected to the first interface circuit, to convert the TTL level signals to physical bus signal or vice versa. The output circuit is connected to the control circuit, to convert the received physical bus signals from the control circuit to network bus signals or vice versa. The power circuit outputs a first voltage and a second voltage converted from the first voltage to the control circuit, the first interface circuit, and the output circuit.