RS232 Cable, Pinout, Uses, Speed
Table of Contents
A serial communication standard for devices is RS232 cable. Although it can also be found in other electronic devices like TVs and printers, it is frequently used to connect computer equipment. The RS232 connector’s pinout reveals that it has 9 pins.
What is the RS232 Protocol?
For serial data communications between computers and other devices, RS232 is the industry standard. The interface for the protocol is a straightforward three-wire setup with a transmit (TX), receive (RX), and ground (GND) line. Data is sent on the TX line serially, which means that each bit is sent one after the other. Data from the TX line is received using the receiving line. Because RS232 is an asynchronous protocol, data transfer is synchronized without the use of a clock signal. The RS232 interface is popular because of how easy it is to use in many different applications, such as industrial control, barcode scanners, and GPS receivers. Additionally, JTAG adapters and other debugging tools frequently use RS232.
RS232, which is an EIA standard, is also referred to as the EIA232 protocol.It is the industry’s most widely used serial communication protocol. The 1960s saw the introduction of RS232. Back then, printers, mice, and modems were typically connected to computers and Programmable Logic Controllers (PLC) using the RS232 protocol. However, modern technologies like Universal Serial Bus (USB) are now taking their place.
What does RS232 stand for?
Every EIA standard begins with RS.Recommended Standard is referred to as RS. However, there is no clear significance to the numbers. In this instance, the EIA has given the number “232” and the letters “RS” to signify the serial communication standard. As a result, serial communication using the RS232 interface is used to transmit binary data between DTEs and DCEs.
A 9-pin DB9 connector is used for the RS232 protocol. The male and female RS232 connectors’ pinouts are displayed below.
The description and arrangement of RS-232 male connector pins are given in the table below.
|1||DCD||Data Carrier Direct|
|4||DTR||Data Terminal Ready|
|6||DSR||Data Set Ready|
|7||RTS||Request To Send|
|8||CTS||Clear To Send|
RS232 Pinout Description
The nine pins of the RS232 connector are divided into three categories:
Data Pins– Through the data pins, the data is transmitted. The data pins are 2 and 3. RxD and TxD pins are these. The data pins are arranged differently on the DTE and DCE.
Control Pins– The interface between the devices is created using the control pins. Pins 1, 4, 6, 7, and 8 are considered control pins.
Reference Pin– The pin designated as the reference voltage is the reference pin. The reference pin, Pin 5, is connected to Ground.
Note: The signal is typically transmitted by a DTE device (male connector) and received by a DCE device (female connector). There are 9 pins on each port. The location of the transmit and receive pins is the only difference in their pinout. The receive pin of a DCE port is located where the transmit pin is in a DTE port.
What is the Speed and Baud rate of the RS232 Cable protocol?
The RS232 protocol can only reliably transfer data over distances of up to 20 meters. Up to 20 kbps (15–20 meters) of asynchronous transmission using the RS232 protocol is possible. The highest data rate, however, is 1Mbps (very short distance). Standard baud rates for cables up to 20 meters in length are 9600, 19200, and 38400. Higher baud rates might or might not be successful, but it’s conceivable. 38400 and 57600 Baud (bits/s), for instance.
What is RS232 Cable used for?
RS232 is primarily used in networks with PLCs, where a PLC uses the RS232 standard to transfer data to other devices. In this instance, the PLCs serve as DTEs while the other hardware, such as printers and modems, serve as DCEs. RS232 is frequently used in serial communication for the following reasons:
- Simple full-duplex communication with 2 pins.
- Systems that struggle to synchronize various clocks can be replaced by RS232 because it supports asynchronous communication.
- Systems that require greater accuracy can use it.
- The best option for instantaneous control of one unit at a time is RS232.
RS232 Cable and Connectors
To support serial data exchange, the RS232 protocol has dedicated cable and connector standards. Let’s learn more about the RS232 cable and connector.
The main purpose of the RS232 connector is to exchange serial data between the DTE and DCE. Typically, the computer and its peripherals will be the subject of this exchange. This protocol was developed to address the drawbacks of parallel data exchange techniques. As you can see, it is larger than the other connectors in terms of size. RS232’s earlier iteration had 25 pins. Later, this was cut down to the 9 pins that are currently in use.
The RS232 protocol’s cables give the terminals the required electrical connection so that data can be transferred. Therefore, regular cables should not be used to connect RS232 terminals. The RS232 standard is connected to using 9-pin DB9 cables. Pins are given a 1:1 order because the connection is between the DTE and DCE. To connect the Nth pin of DTE to the Nth pin of DCE, as a result, is what this means. Thus, in the RS232 protocol, there is no crossover connection.