#Rs 232 connector generator
#Rs 232 connector serial

For short low-capacitance cables, data rates can be as high as several megabits per second with the appropriate drivers. The data rate is limited by the maximum allowed slew rate of 30 V/Вµs (volts per microsecond). Today, data rates are defined by the protocol used with the interface and can range as high as 115.2 kbits/s. A minimum rate was typically 75 bits/s, but rates of 150 and 300 bits/s were common. Originally, data rates for electromechanical equipment were very slow. Instead, a nine-pin connector called the DE-9 was defined, and today it is the de facto standard (Fig.

#Rs 232 connector serial

The standard defined a 25-pin connector called the DB-25, which was designed to carry a variety of control lines as well as the serial data transmit and receive lines.

#Rs 232 connector generator

Transmission lines require matched generator and load impedances to eliminate reflections that cause data corruption. Because of the low-speed data rates used with this interface, the cable generally isnвЂ™t treated as a formal transmission line. This limits the upper data rate to roughly 20 kbits/s.

Today the primary goal is to use a cable with no more than 2500 pF of capacitance between wires. However, much longer cable lengths can be used with low data rate conditions. The length of the cable determines the upper data rate and generally should not exceed 50 feet. The cable medium can be simple parallel wires or twisted pair. The transmitter and receiver configurations are single-ended (not differential) with a ground reference. In common practice, logic 0 and 1 levels are typically as low as В±5 V and as high as в‘2 or в‘5 V. Noise voltages in this range are rejected. Voltages between в“ V are invalid, providing a huge noise margin for the interface. Signal levels are commonly referred to as a mark for logic 1 and a space for logic 0. The standard defines a logic 1 and a voltage between вЂ“3 and вЂ“25 V and a logic 0 as a voltage level between +3 and + 25 V (Fig.

The standard is essentially the same as the International Telecommunications Union вЂ“ Telecommunications (ITU-T) specifications V.24 and V.28. The letter F designates the most recent standard modification and update. The official name of the standard is Electronic Industries Association/Telecommunications Industries Association EIA/TIA-232-F. Today, it is still widely used in embedded computer development systems, scientific instruments, and all sorts of industrial control equipment. The first personal computers included an RS-232 called a serial port for connection to a printer or other peripheral device. Over the years its use has included connections to video terminals, computers, and modems. It was originally established in 1962 as a method of connecting data terminal equipment (DTE) such as electromechanical teletypewriters to data communications equipment (DCE). One of the oldest serial interfaces is generically called RS-232. Any additional functions such as data handling is part of the media access control (MAC) layer or layer 2 of the OSI model. The definition of logic levels, medium, and connectors is part of the physical layer (PHY) or layer 1 of the Open Systems Interconnection (OSI) networking model. In some cases, they can perform serial-to-parallel and parallel-to-serial conversion or specify a basic data protocol. Serial interfaces can be used to provide standardized logic levels from transmitters to receivers, define the transmission medium and connectors, and specify timing and data rates. But with high-speed data so common today, a serial interface is the only practical option for communications over any distance greater than several feet.

Parallel buses are still used in some applications. The whole purpose of a serial interface is to provide a single path for data transmission wirelessly or over a cable. Both are still alive and well in many applications. These legacy interfaces arenвЂ™t obsolete or discontinued, though. Two of the oldest interfaces are RS-232 and RS-485. Then thereвЂ™s Ethernet and USB and other higher-speed serial interfaces like FireWire, HDMI, and Thunderbolt. A few have become universal, such as I 2C, CAN, LIN, SPI, Flex, MOST, and I 2S. Most have been developed for specific applications. This article is part of the Communication Series: WhatвЂ™s the Difference: Serial Communications 101Дozens of serial data interfaces are used today.