#Schema cavo seriale 9 pin dritto serial

Modem speeds of 300 baud were common and 1200 baud was seen as a high speed connection.ДЇor further control of the information flow, both devices have the ability to signal their status to the other side. The assumption is, that the DTE can always handle incomming information faster than the DCE can send it. A simple but useful mechanism allowing flow control in one direction. If the DCE cannot handle new requests, the CTS signal will go low. No information will be sent until the DCE grants permission by using the CTS line. CTS is the answering signal comming from the DCE.Д«efore sending a character, the DTE asks permission by setting its RTS output.

a computer communicating with a modem device) RTS is an output on the DTE and input on the DCE. These two pins are RTS, request to send and CTS, clear to send. When we look at the connector pinout of the RS232 port, we see two pins which are certainly used for flow control. If no flow control is implemented in the null modem connection, communication is only possible at speeds at which it is sure the receiving side can handle the amount information even under worst case conditions. High amounts of incomming data is allowed if the computer is capable to handle it, but not if it is busy performing other tasks. Handshaking can increase the maximum allowed communication speed because it gives the computers the ability to control the flow of information.

In most situations, the original modem signal lines are reused to perform some sort of handshaking.

#Schema cavo seriale 9 pin dritto serial

In history, practical solutions were developed to let two computers talk with each other using a null modem serial communication line. The terminology null modem for the situation where two computers communicate directly is so often used nowadays, that most people donвЂ™t realize anymore the origin of the phrase and that a null modem connection is an exception, not the rule. One of the main uses of serial communication today where no modem is involved-a serial null modem configuration with DTE/DTE communication-is not so well defined, especially when it comes to flow control. For your information, DTE means data terminal equipment (computers etc.) where DCE is the abbreviation of data communication equipment (modems). The standards show the use of DTE/DCE communication, the way a computer should communicate with a peripheral device like a modem. The way this type of communication can be performed is pretty well defined in standards. One of the oldest and most widely spread communication methods in computer world.