Talk:Asynchronous serial communication

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[edit] Stray paragraph

Why was this put in?

To limit cable costs, all telecommunication equipment employs multiplexing. For example Morse code employs a series of dots and dashes to represent a character. Dots are short pulses of electrical current compared to the longer dash pulses. Thus, short and long pulses are multiplexed on the same wire (circuit) over time. In modern telecommunications, pulses are usually the same duration and a group of pulses are sent together to represent one character code. A pulse can only be in one of two states but there are many names for the two states.

When on, circuit closed, low voltage, current flowing, or a logical zero, the pulse is said to be in the "space" condition.

When off, circuit open, high voltage, current stopped, or a logical one, the pulse is said to be in the "mark" condition. A character code begins with the data communication circuit in the space condition. If the mark condition appears, a logical one is recorded otherwise a logical zero.

This is a general discussion of electrical signalling and not really the point of this article. --Wtshymanski 17:45, 24 August 2007 (UTC)