Tech Info - RS232 Cables and Wiring. Brief tutorial and pinouts for RS-232, T1/E1 and V.35.
If you want to know more about RS 232 signals then this page may help - but you may also need to lie down in a darkened room afterwards. Contents RS-232 standards(EIA-232) are defined by EIA/TIA (Electronic Industries Alliance /Telecommunications Industry Association). RS-232 defines both the physical and electrical characteristics of the interface. RS-232 is practically identical to ITU V.24 (signal description and names) and V.28 (electrical). Signal = 0 (LOW) > +3.0V (SPACE)Signal = 1 (HIGH) < -3.0V (MARK) Notes: Signal voltages in the range >-3.0V to +3.0V are regarded as being in the 'dead area' (indeterminate value) and allow for absorption of noise.
DTE (PC) and DCE (Modem) In serial communications the terminal end (PC) is called the Data Terminal Equipment (DTE) and the modem end is called the Data Communications Equipment (DCE) as shown in the diagram below. Serial Communications with a modem NULL Modem Connections. The RS232 Standard. (renamed the "EIA232 Standard" in the early 1990's) Written by Christopher E.
Strangio Copyright © 1993-2012 by CAMI Research Inc., Acton, Massachusetts Send Us Your Comments . . . Contents What is EIA232? Pin Description Index References to EIA Publications Back to CableEye® Home Page What is EIA232? In the early 1960s, a standards committee, today known as the Electronic Industries Association, developed a common interface standard for data communications equipment.
Over the 40+ years since this standard was developed, the Electronic Industries Association published three modifications, the most recent being the EIA232F standard introduced in 1997. Likely Problems when Using an EIA232 Interface Next Topic | Previous Topic | TOC. Serial port, RS232 and RS485 software and shareware developer tools. RS-232 Bus Description and EIA232 Pinout. Interface Between Data Terminal Equipment and Data Circuit Terminating Equipment Employing Serial Binary Data Interchange [RS232 Description] [RS232 Standard Organizations] [RS232 Interface ICs] [RS232 Pin-Out] ['D' Connectors] [Home] EIA-232 Description The RS232 specification defines both the Mechanical, Electrical, and Functional characteristics of the interface.
RS232 is an Unbalanced (Single Ended), unidirectional (point-to-point) interface, with the signal referenced to ground. RS232 drivers feature a controlled slew rate. The RS232 interface is synchronous when the clocks are used (DA / DB), otherwise its asynchronous. The stop bit is used to bring [or insure] the signal rests at a logic high following the end of the frame; so when the next start bit arrives it will bring the bus from a high to low ~ remember we will invert, so on the RS232 cable the stop bit is low and the start bit will transition low to high.
RS-232 Voltage Levels EIA-232 Cable Distance vs. {RS232 Bus Index}