Transmitter and monitoring system using the same

A monitoring system, comprising:

• a plurality of sensors configured to generate a plurality of sensor signals of a plurality of channels;
• a transmitter configured to comprise:
• a multi-to-one multiplexing switch configured to receive the plurality of sensor signals of the plurality of channels through a plurality of input terminals, select one sensor signal from the plurality of sensor signals, and output the selected sensor signal through a output terminal;
• a first variable gain amplifier configured to receive the selected sensor signal, amplify the selected sensor signal with a gain within a first gain range, and output the amplified sensor signal;
• a control parameter input terminal configured to receive an input control parameter from outside of the transmitter;
• and
• an operating and switching selector configured to perform operations according to the input control parameter, so as to control the multi-to-one multiplexing switch to select the one sensor signal and control the gain of the first variable gain amplifier;
• an analog/digital converter configured to receive the amplified sensor signals output from the transmitter, and convert the amplified sensor signals into digital sensor signals;
• an interface circuit configured to receive the digital sensor signals, and encode and capsulate the digital sensor signals into a digital output;
• and
• a central control unit configured to send the input control parameter to the transmitter, receive the digital output, and decapsulate and decode the digital output, so as to reproduce and display the plurality of sensor signals.