Rs 232 standards pdf

The RS standard provided an ideal method of connection and therefore it started to be used in a rather different way. However its use really started to take off when personal computers were first introduced. Here the RS standard provided an ideal method of linking the PC to the printer. The RS standard provided an ideal method of linking many other remote items to computers and data recorders. As a result, RS became an industry standard, used in a host of applications that were never conceived when it was first launched in The RS standard has a variety of updates and minor variations as a result of being taken on by a number of different bodies.

For the most part these different standards are interchangeable and RS and V24, for example are exactly the same for most applications. The standard has been in use for over half a century and in that time it has provided reliable and effective communications over a serial link.

RS standard variants There are number of different specifications and standards that relate to RS RSC: This was the designation given to the release of RS standard updated in to incorporate many of the device characteristics.

RSF: This version of the RS standard was released in to accommodate further revisions to the standard. Parallel communications are used.

Serial transmission involves the. In contrast, parallel communications. Serial transmission is beneficial. One of the advantages of a serial. The serial digital data can be. Officially, RS is defined as the. A modem cable has pin-to-pin. Selecting a Cable. In addition to communications. The major consideration in choosing. First, are you. As in the. However, many interface. Usually, it is recommended that the. Alternatively, the DTE device may be programmed to ignore this signal.

If the DCE device is a modem, the assertion of DTE Ready prepares the modem to be connected to the telephone circuit, and, once connected, maintains the connection. When DTE Ready is deasserted logic '1', negative voltage , the modem is switched to "on-hook" to terminate the connection.

If the DCE device for example, a printer is not responding, confirm that DTE Ready is asserted before you search for other explanations. It is asserted logic '0', positive voltage by the modem when the telephone line is "off-hook", a connection has been established, and an answer tone is being received from the remote modem. The signal is deasserted when no answer tone is being received, or when the answer tone is of inadequate quality to meet the local modem's requirements perhaps due to a noisy channel.

Pin 22 - Ring Indicator RI This signal is relevant when the DCE device is a modem, and is asserted logic '0', positive voltage when a ringing signal is being received from the telephone line.

The assertion time of this signal will approximately equal the duration of the ring signal, and it will be deasserted between rings or when no ringing is present.

The asserted condition logic '0', positive voltage selects the higher baud rate. NOTE: optical isolators may be used to achieve ground isolation, however, this option is not mentioned or included in the EIA specification. Voltage magnitudes will be slightly less when the generator and receiver are connected when the DTE and DCE devices are connected with a cable. Also note that some inexpensive EIA peripherals are powered directly from the signal lines to avoid using a power supply of their own.

Although this usually works without problems, keep the cable short, and be aware that noise immunity will be reduced. Short-Circuit Tolerance - The generator is designed to withstand an open-circuit unconnected condition, or short-circuit condition between its signal conductor and any other signal conductor, including ground, without sustaining damage to itself or causing damage to any associated circuitry. Keep the cable length as short as possible, and avoid running the cable near high-current switching loads like electric motors or relays.