requesttosend

Request To Send, often abbreviated as RTS, is a hardware flow control signal used in serial communication. It is part of the RS-232 standard, a widely adopted specification for serial binary data exchange between devices. RTS is one of two primary hardware flow control signals, the other being Clear To Send (CTS).

The purpose of RTS is for a data terminal equipment (DTE) device, such as a computer, to indicate to a data communications equipment (DCE) device, like a modem, that it is ready to send data. When the DTE asserts the RTS signal (typically by setting its voltage level to a specific state), it is signaling its readiness to transmit.

Conversely, the DCE device monitors the RTS signal. If the DCE is also ready to receive data from the DTE, it will assert the CTS signal in response. If the DCE is busy and cannot accept more data, it will de-assert CTS, thereby preventing the DTE from sending further data until it is ready again. This mechanism helps to prevent data overflow and ensures that data is transmitted only when both devices are prepared to handle it.

RTS and CTS work in tandem to manage the flow of data in serial communication, particularly in older systems or when software flow control is not feasible or desired. It is a fundamental component of ensuring reliable data transfer over serial links by preventing buffer overflows and lost data.