Digital Communications

Network Protocols in Digital Communication: “Intelligent” (microprocessor-controlled) switching systems have become the hubs of intelligent networks. Terminal devices and line connection equipment have also been given microprocessor “brains,” and thus the introduction of intelligent devices into the data communications field has brought a sophistication to the interconnection possibilities. With terminals capable of establishing circuit connections […]

Switching Systems in Digital Communication: If only two sites are to be connected, switching is not required. The two facilities are interconnected on a point-to-point basis. However, switching is likely to be required where three or more sites need to be interconnected. The various types of Switching Systems in Digital Communication described earlier can all

Centralized Switched Telephone Network: Centralized Switched Telephone Network – As data systems have increased in number and complexity, it has become increasingly important to provide for their proper and orderly interconnection. Small, simple systems could dedicate individual lines for each piece of equipment which was connected in the system. For intraplant connections, this was a

Interconnection of Data Circuits: In the United States, a recent FCC ruling, in part 68 of the Rules and Regulations, permits for the first time non-telephone company interconnection to telephone company circuits. This ruling has placed the responsibility for much of the necessary Interconnection of Data Circuits on the manufacturer of data equipment, which must

RS 232 Interface Modem: In the United States, a standard interconnection between business machine and modem is supplied by the RS 232 Interface Modem. RS 232 Interface Modem has been defined by the Electronic Industries Association (EIA) to ensure compatibility between data sets and terminal equipment. The interface uses a 25-pin Cannon or Cinch plug,

Data Communication Circuit using Modem: Data Communication Circuit using Modem – The name modem is a contraction of the term MOdulator and DEModulator. As the name implies, both functions are included in a modem. When used in the transmitting mode, the modem accepts digital data and converts it to analog signals for use in modulating

Error Detection and Correction Codes: Error Detection and Correction Codes – Errors enter the data stream during transmission and are caused by noise and transmission system impairments. Because errors compromise the data and in some cases render it useless, procedures have been developed to detect and correct transmission errors. The processes involved with error correction

Digital Codes Types: Various Digital Codes Types of equipment are used in computer systems to send and receive data: keyboards, video terminals, printers, paper tape punches and readers, paper card punches and readers, and magnetic storage devices. Each of these types of equipment generates and receives data in the form of Digital Codes Types. The

Characteristics of Data Transmission Circuits: Bandwidth Requirements – Characteristics of Data Transmission Circuits is the most instances consists of pulse-type energy. The data stream is similar to a square-wave signal with rapid transitions from one voltage level to another, with the repetition rate depending on the binary representation of the data word. For instance, if

Digital Electronics Basics: Digital devices are based on Digital Electronics Basics circuits which can represent two states, ON or OFF. The ability to design integrated circuits consisting of thousands of transistors on wafer-thin; postage-stamp-sized chips has made Digital Electronics Basics both feasible and extraordinarily powerful. The chants are used to store, evaluate, manipulate and modify