Dtmf Encoder And Decoder Using Labview

In this paper, a laboratory experiment is presented for a senior technical elective course in telecommunications in the Electrical Engineering Technology Baccalaureate program at Penn State Erie, The Behrend College. For this experiment, students use LabVIEW and a PC-based data acquisition (DAQ) system to design a dual-tone multifrequency (DTMF) encoder and decoder. The user input for the encoder is from a 12-pushbutton external keypad used to simulate the touch-tone telephone keypad. The output of the decoder is a 7-segment display used to indicate the depressed pushbutton. The encoder and decoder are each implemented on a separate PC-based DAQ system. They are interconnected with a signal wire and a ground wire, simulating the telephone line.