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It was first published in paperback by Davis Publications in November 1984, with a hardcover edition following from The Dial Press in December 1984 under the alternate title From Mind to Mind: Tales of Communication from Analog. [1] The book collects sixteen short stories, novelettes and novellas first published in Analog and its predecessor ...
Analog discrete-time signal processing is a technology based on electronic devices such as sample and hold circuits, analog time-division multiplexers, analog delay lines and analog feedback shift registers. This technology was a predecessor of digital signal processing (see below), and is still used in advanced processing of gigahertz signals. [7]
Analog transmission is a transmission method of conveying information using a continuous signal which varies in amplitude, phase, or some other property in proportion to that information. It could be the transfer of an analog signal, using an analog modulation method such as frequency modulation (FM) or amplitude modulation (AM), or no ...
Digitizing, or converting analog signals into digital form, was first developed in 1903 with the invention of pulse-code modulation (PCM) for telephone communications. [13] Electronic encryption, which allowed for the secure transmission of information over electronic channels, was developed between 1935 and 1945 and played a crucial role in ...
Analog current loops were historically occasionally carried between buildings by dry pairs in telephone cables leased from the local telephone company. 4–20 mA loops were more common in the days of analog telephony. These circuits require end-to-end direct current (DC) continuity, and unless a dedicated wire pair was hardwired, their use ...
The HART Communication Protocol (Highway Addressable Remote Transducer) is a hybrid analog+digital industrial automation open protocol. Its most notable advantage is that it can communicate over legacy 4–20 mA analog instrumentation current loops, sharing the pair of wires used by the analog-only host systems.
Pulse-amplitude modulation (PAM) is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. It is an analog pulse modulation scheme in which the amplitudes of a train of carrier pulses are varied according to the sample value of the message signal.
An analog signal uses some property of the medium to convey the signal's information. For example, an aneroid barometer uses rotary position as the signal to convey pressure information. In an electrical signal, the voltage , current , or frequency of the signal may be varied to represent the information.