N-GEN
Communications Web-based Seminars ©NGCS
Seminar - An Overview of Communications Technologies
Seminar - An Overview of Communications Technologies
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Module 2 - Data Communications Basics and Legacy Technologies Slide 11 of 45 _________________ __________ Building Blocks - Data Transmission Methods
_________________ __________ Data transmission methods have evolved with the applications. The asynchronous data transmission method was devised to transfer information from a computer to a mechanical terminal and vice versa. The synchronous transmission method was devised for large data transmission. Isochronous transmission method was devised for alarm control. Asynchronous Data Transmission Method - A character by character transmission. Each character code has start and stop bits for the mechanical devices to adjust time to receive the next character. Synchronous Data Transmission Method - At the start and the end of the bulk data transmission, control characters are sent to synchronize the receiving clock and to signify the end of transmission. Error checking information is also added to the transmitted data. Isochronous Data Transmission Method - It is similar in nature to the asynchronous data transmission method except for fixed interval between two characters. It is designed to collect polled alarm information and send it in bulk.
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Asynchronous Data Transmission
