MICROPROCESSOR FSK DATA COMMUNICATIONS MODULE

摘要

Title MICROPROCESSOR FSK DATA COMMUNICATIONS MODULE Inventors Mark E. Nurczyk Patrick J. Wilson Tony J. Wood A microprocessor-based frequency shift keying (FSK) data communications module. The microprocessor selectively modulates and demodulates data directly in terms of a square wave pulse train in which a first frequency is used to convey a binary "1" and a second frequency to convey a binary "O". An input and an output port on the microprocessor are selectively coupled to a transmission line through a transformer, by means of electronic switches. Also included are a bandpass filter for shaping the square waves into sine waves and for filtering noise, and means including a notch filter for generating a carrier detect signal input to the microprocessor, when incoming data is detected on the transmission line. Many of the components in the module are used for both transmitting and receiving data.