ft232 cp2102 pl2303 usb rs232 serial cable ftdi cable rs232 for android stb to tv control
100-199 PiecesUS $6.60
>=200 PiecesUS $5.60
- Place brand on product (example) US $0.1 / Piece
- Place brand on package US $0.1 / Piece
- Brand Name:
- Model Number:
- Place of Origin:
Guangdong, China (Mainland)
Camera, Computer, Mobile Phone, MP3 / MP4 Player, Video Game Player, Android TV
- USB Type:
ft232 cp2102 pl2303 usb rs232 serial cable ftdi cable rs232
FT232RL USB RS232 to RJ9 4P4C
PL2303TA USB RS232 to RJ9 cable
CP2102 USB RS232 to RJ9 cable
TXD, RXD, CTS, RTS, GND optional
Support Win 7, Win 8, Win 10, Android, Mac, Linux, Win ce
In telecommunications, RS-232 is a standard for serial communication transmission of data. It formally defines the signals connecting between a DTE (data terminal equipment) such as a computer terminal, and a DCE (data circuit-terminating equipment or data communication equipment), such as a modem. The RS-232 standard is commonly used in computer serial ports. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. The current version of the standard is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997.
An RS-232 serial port was once a standard feature of a personal computer, used for connections to modems, printers, mice, data storage, uninterruptible power supplies, and other peripheral devices. However, RS-232, when compared to other serial interfaces such as RS-422, RS-485 and Ethernet, is hampered by low transmission speed, short maximum cable length, large voltage swing, large standard connectors, no multipoint capability and limited multidrop capability. In modern personal computers, USB has displaced RS-232 from most of its peripheral interface roles. Many computers no longer come equipped with RS-232 ports (although some motherboards come equipped with a COM port header that allows the user to install a bracket with a DE-9 port) and must use either an external USB-to-RS-232 converter or an internal expansion card with one or more serial ports to connect to RS-232 peripherals. Nevertheless, thanks to their simplicity and past ubiquity, RS-232 interfaces are still used—particularly in industrial machines, networking equipment, and scientific instruments where a short-range, point-to-point, low-speed wired data connection is adequate.
Scope of the standard
The Electronic Industries Association (EIA) standard RS-232-C as of 1969 defines:
Electrical signal characteristics such as voltage levels, signaling rate, timing, and slew-rate of signals, voltage withstand level, short-circuit behavior, and maximum load capacitance.
Interface mechanical characteristics, pluggable connectors and pin identification.
Functions of each circuit in the interface connector.
Standard subsets of interface circuits for selected telecom applications.
The standard does not define such elements as the character encoding (i.e. ASCII, EBCDIC, or others), the framing of characters (start or stop bits, etc.), transmission order of bits, or error detection protocols. The character format and transmission bit rate are set by the serial port hardware which may also contain circuits to convert the internal logic levels to RS-232 compatible signal levels. The standard does not define bit rates for transmission, except that it says it is intended for bit rates lower than 20,000 bits per second.
RS-232 was first introduced in 1960 by the Electronic Industries Association (EIA) as a Recommended Standard. The original DTEs were electromechanical teletypewriters, and the original DCEs were (usually) modems. When electronic terminals (smart and dumb) began to be used, they were often designed to be interchangeable with teletypewriters, and so supported RS-232. The C revision of the standard was issued in 1969 in part to accommodate the electrical characteristics of these devices.
Because the standard did not foresee the requirements of devices such as computers, printers, test instruments, POS terminals, and so on, designers implementing an RS-232 compatible interface on their equipment often interpreted the standard idiosyncratically. The resulting common problems were non-standard pin assignment of circuits on connectors, and incorrect or missing control signals. The lack of adherence to the standards produced a thriving industry of breakout boxes, patch boxes, test equipment, books, and other aids for the connection of disparate equipment. A common deviation from the standard was to drive the signals at a reduced voltage. Some manufacturers therefore built transmitters that supplied +5 V and −5 V and labeled them as "RS-232 compatible".
Later personal computers (and other devices) started to make use of the standard so that they could connect to existing equipment. For many years, an RS-232-compatible port was a standard feature for serial communications, such as modem connections, on many computers (with the computer acting as the DTE). It remained in widespread use into the late 1990s. In personal computer peripherals, it has largely been supplanted by other interface standards, such as USB. RS-232 is still used to connect older designs of peripherals, industrial equipment (such as PLCs), console ports, and special purpose equipment.
The standard has been renamed several times during its history as the sponsoring organization changed its name, and has been variously known as EIA RS-232, EIA 232, and, most recently as TIA 232. The standard continued to be revised and updated by the Electronic Industries Association and since 1988 by the Telecommunications Industry Association (TIA). Revision C was issued in a document dated August 1969. Revision D was issued in 1986. The current revision is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997. Changes since Revision C have been in timing and details intended to improve harmonization with the CCITT standard V.24, but equipment built to the current standard will interoperate with older versions.
Related ITU-T standards include V.24 (circuit identification) and V.28 (signal voltage and timing characteristics).
In revision D of EIA-232, the D-subminiature connector was formally included as part of the standard (it was only referenced in the appendix of RS-232-C). The voltage range was extended to ±25 volts, and the circuit capacitance limit was expressly stated as 2500 pF. Revision E of EIA-232 introduced a new, smaller, standard D-shell 26-pin "Alt A" connector, and made other changes to improve compatibility with CCITT standards V.24, V.28 and ISO 2110.
EIA RS-232 (May 1960) "Interface Between Data Terminal Equipment & Data"
EIA RS-232-A (October 1963)
EIA RS-232-B (October 1965)
EIA RS-232-C (August 1969) "Interface Between Data Terminal Equipment and Data Communication Equipment Employing Serial Binary Data Interchange"
EIA EIA-232-D (1986)
TIA TIA/EIA-232-E (1991) "Interface Between Data Terminal Equipment and Data Communications Equipment Employing Serial Binary Data Interchange"
TIA TIA/EIA-232-F (1997-10-01)
TIA TIA-232-F (R2012)
Limitations of the standard
Because RS-232 is used beyond the original purpose of interconnecting a terminal with a modem, successor standards have been developed to address the limitations. Issues with the RS-232 standard include:
The large voltage swings and requirement for positive and negative supplies increases power consumption of the interface and complicates power supply design. The voltage swing requirement also limits the upper speed of a compatible interface.
Single-ended signaling referred to a common signal ground limits the noise immunity and transmission distance.
Multi-drop connection among more than two devices is not defined. While multi-drop "work-arounds" have been devised, they have limitations in speed and compatibility.
For peripherals connecting to a PC, the PC is DTE, and the peripheral is DCE. If identical units need to interconnect then a cross-over or null-modem cable is needed.
The standard does not address the possibility of connecting a DTE directly to a DTE, or a DCE to a DCE. Null modem cables can be used to achieve these connections, but these are not defined by the standard, and some such cables use different connections than others.
The definitions of the two ends of the link are asymmetric. This makes the assignment of the role of a newly developed device problematic; the designer must decide on either a DTE-like or DCE-like interface and which connector pin assignments to use.
The handshaking and control lines of the interface are intended for the setup and takedown of a dial-up communication circuit; in particular, the use of handshake lines for flow control is not reliably implemented in many devices.
No method is specified for sending power to a device. While a small amount of current can be extracted from the DTR and RTS lines, this is only suitable for low-power devices such as mice.
The 25-pin D-sub connector recommended in the standard is large compared to current practice
Role in modern personal computers
In the book PC 97 Hardware Design Guide, Microsoft deprecated support for the RS-232 compatible serial port of the original IBM PC design. Today, RS-232 has mostly been replaced in personal computers by USB for local communications. Compared with RS-232, USB is faster, uses lower voltages, and has connectors that are simpler to connect and use. However, USB is limited by standard to no more than 5 meters of cable, thus favoring RS-232 when longer distances are needed. Both standards have software support in popular operating systems.
USB is designed to make it easy for device drivers to communicate with hardware. USB is more complex than the RS-232 standard because it includes a protocol for transferring data to devices. This requires more software to support the protocol used. There is no direct analog to the terminal emulator programs that let users communicate directly with serial ports.
Serial ports of personal computers are also sometimes used to directly control various hardware devices, such as relays or lamps. Personal computers may use a serial port to interface to devices such as uninterruptible power supplies. In some cases, serial data is not exchanged, but the control lines are used to signal conditions such as loss of power or low battery alarms. An application program can detect or change the state of RS-232 control lines in the registers of the serial hardware using only a few input/output instructions; by contrast, a USB interface requires software to decode the serial data.
Due to compatibility of various device driver programs for respective devices that convert between USB and RS-232, such devices do not work with every OS.[vague][dubious – discuss]
In fields such as laboratory automation or surveying, RS-232 devices may continue to be used. PLCs, VFDs, servo drives, and CNC equipment are programmable via RS-232. Some manufacturers have responded to this demand by re-introducing the DE-9M connector on their computers.
RS-232 ports are also commonly used to communicate to headless systems such as servers, where no monitor or keyboard is installed, during boot when operating system is not running yet and therefore no network connection is possible. A computer with an RS-232 serial port can communicate with the serial port of an embedded system (such as a router) as an alternative to monitoring over Ethernet.
In RS-232, user data is sent as a time-series of bits. Both synchronous and asynchronous transmissions are supported by the standard. In addition to the data circuits, the standard defines a number of control circuits used to manage the connection between the DTE and DCE. Each data or control circuit only operates in one direction, that is, signaling from a DTE to the attached DCE or the reverse. Because transmit data and receive data are separate circuits, the interface can operate in a full duplex manner, supporting concurrent data flow in both directions. The standard does not define character framing within the data stream, or character encoding.
Diagrammatic oscilloscope trace of voltage levels for an ASCII "K" character (0x4B) with 1 start bit, 8 data bits, 1 stop bit. This is typical for start-stop communications, but the standard does not dictate a character format or bit order.
RS-232 data line on the terminals of the receiver side (RxD) probed by an oscilloscope (for an ASCII "K" character (0x4B) with 1 start bit, 8 data bits, 1 stop bit, and no parity bits).
The RS-232 standard defines the voltage levels that correspond to logical one and logical zero levels for the data transmission and the control signal lines. Valid signals are either in the range of +3 to +15 volts or the range −3 to −15 volts with respect to the "Common Ground" (GND) pin; consequently, the range between −3 to +3 volts is not a valid RS-232 level. For data transmission lines (TxD, RxD, and their secondary channel equivalents), logic one is defined as a negative voltage, the signal condition is called "mark". Logic zero is positive and the signal condition is termed "space". Control signals have the opposite polarity: the asserted or active state is positive voltage and the deasserted or inactive state is negative voltage. Examples of control lines include request to send (RTS), clear to send (CTS), data terminal ready (DTR), and data set ready (DSR).
The standard specifies a maximum open-circuit voltage of 25 volts: signal levels of ±5 V, ±10 V, ±12 V, and ±15 V are all commonly seen depending on the voltages available to the line driver circuit. Some RS-232 driver chips have inbuilt circuitry to produce the required voltages from a 3 or 5 volt supply. RS-232 drivers and receivers must be able to withstand indefinite short circuit to ground or to any voltage level up to ±25 volts. The slew rate, or how fast the signal changes between levels, is also controlled.
Because the voltage levels are higher than logic levels typically used by integrated circuits, special intervening driver circuits are required to translate logic levels. These also protect the device's internal circuitry from short circuits or transients that may appear on the RS-232 interface, and provide sufficient current to comply with the slew rate requirements for data transmission.
Because both ends of the RS-232 circuit depend on the ground pin being zero volts, problems will occur when connecting machinery and computers where the voltage between the ground pin on one end, and the ground pin on the other is not zero. This may also cause a hazardous ground loop. Use of a common ground limits RS-232 to applications with relatively short cables. If the two devices are far enough apart or on separate power systems, the local ground connections at either end of the cable will have differing voltages; this difference will reduce the noise margin of the signals. Balanced, differential serial connections such as RS-422, RS-485, and USB can tolerate larger ground voltage differences because of the differential signaling.
Unused interface signals terminated to ground will have an undefined logic state. Where it is necessary to permanently set a control signal to a defined state, it must be connected to a voltage source that asserts the logic 1 or logic 0 level, for example with a pullup resistor. Some devices provide test voltages on their interface connectors for this purpose.
RS-232 devices may be classified as Data Terminal Equipment (DTE) or Data Circuit-terminating Equipment (DCE); this defines at each device which wires will be sending and receiving each signal. According to the standard, male connectors have DTE pin functions, and female connectors have DCE pin functions. Other devices may have any combination of connector gender and pin definitions. Many terminals were manufactured with female connectors but were sold with a cable with male connectors at each end; the terminal with its cable satisfied the recommendations in the standard.
The standard recommends the D-subminiature 25-pin connector, but does not make it mandatory. Most devices only implement or use a few of the twenty signals specified in the standard, so connectors and cables with fewer pins are sufficient for most connections, more compact, and less expensive. Personal computer manufacturers replaced the DB-25M connector with the smaller DE-9M connector. This connector, with a different pinout (see Serial port pinouts), is prevalent for personal computers and associated devices.
Presence of a 25-pin D-sub connector does not necessarily indicate an RS-232-C compliant interface. For example, on the original IBM PC, a male D-sub was an RS-232-C DTE port (with a non-standard current loop interface on reserved pins), but the female D-sub connector on the same PC model was used for the parallel "Centronics" printer port. Some personal computers put non-standard voltages or signals on some pins of their serial ports
The standard does not define a maximum cable length, but instead defines the maximum capacitance that a compliant drive circuit must tolerate. A widely used rule of thumb indicates that cables more than 15 m (50 ft) long will have too much capacitance, unless special cables are used. By using low-capacitance cables, full speed[clarification needed] communication can be maintained over larger distances up to about 300 m (1,000 ft). For longer distances, other signal standards are better suited to maintain high speed.
Since the standard definitions are not always correctly applied, it is often necessary to consult documentation, test connections with a breakout box, or use trial and error to find a cable that works when interconnecting two devices. Connecting a fully standard-compliant DCE device and DTE device would use a cable that connects identical pin numbers in each connector (a so-called "straight cable"). "Gender changers" are available to solve gender mismatches between cables and connectors. Connecting devices with different types of connectors requires a cable that connects the corresponding pins according to the table above. Cables with 9 pins on one end and 25 on the other are common. Manufacturers of equipment with 8P8C connectors usually provide a cable with either a DB-25 or DE-9 connector (or sometimes interchangeable connectors so they can work with multiple devices). Poor-quality cables can cause false signals by crosstalk between data and control lines (such as Ring Indicator).
If a given cable will not allow a data connection, especially if a gender changer is in use, a null modem cable may be necessary. Gender changers and null modem cables are not mentioned in the standard, so there is no officially sanctioned design for them.
3-wire and 5-wire RS-232
A minimal "3-wire" RS-232 connection consisting only of transmit data, receive data, and ground, is commonly used when the full facilities of RS-232 are not required. Even a two-wire connection (data and ground) can be used if the data flow is one way (for example, a digital postal scale that periodically sends a weight reading, or a GPS receiver that periodically sends position, if no configuration via RS-232 is necessary). When only hardware flow control is required in addition to two-way data, the RTS and CTS lines are added in a 5-wire version.
Shenzhen Sinforcon Electronics Ltd, established in 2002, is a private enterprise in usb serial cables manufacturing fields. The main business are ranging of usb rs232, usb ttl, usb rs485 cables manufacture and customized services. It has a 3000 square meters and 120 workers manufacture sites in Dongguan, China. The manufacturing capacity is 300000 ~ 500000 per month. And it was certificated by TUV, CE, ROHS, REACH, etc.
Q: Can I buy the cable online?
A: Yes, please buy it on aliexpress.com/store/401907, it support credit card payment.
Q: Does this cable need to install driver?
A: Yes, it need to install the USB serial drivers for different OS
Q: Where should I get the drivers?
A: From sinforcon.com/download or the chips supplier website or email us
FTDI drivers download link:
Driver installing guide:
FT232RL chip datasheet:
Q: How to install the USB RS232 drivers?
A: There is a driver installing guide on chip manufacture websites or email us.
Q: Does the cable support Win 7/8/10
A: Yes, all Sinforcon cables are supplrt Window 7/8/8.1/10
Q: What is the chip can support Android, Mac?
A: FT232RL FT231XS FT230XS PL2303HXD CP2102 support Mac, Android,WIN8/10
PL2303TA support Win8/10,not support Android, Mac
Q: Does the cable support invert RXD/TXD signals?
A: FT232RL chip cable support FT_prog.
Q: How to get fastest reply from Sinforcon?
A: By alibaba Trade manager, ID1: connectingcables or skype: richard90072000
Q: Does the cable with CE, RoHS, REACH certificate
A: Yes. if you need it, email us please