Data Terminal Ready

Data Terminal Ready

Data Terminal Ready (DTR) signal

Data Terminal Ready (DTR) is a control signal used in serial communication protocols, such as RS-232, to indicate the readiness of a data terminal equipment (DTE) to establish a connection with a data communication equipment (DCE). It is one of the many control signals that facilitate the flow of data between devices.

Overview

The DTR signal is typically sent by the DTE to the DCE to indicate that it is ready to send or receive data. When the DTR signal is active, it signifies that the DTE is powered on and ready to establish a connection. Conversely, when the DTR signal is inactive, it indicates that the DTE is not ready or powered off.

Usage

The DTR signal is commonly used in scenarios where a DTE, such as a computer or a modem, needs to establish a connection with a DCE, such as a modem or a serial device. By asserting the DTR signal, the DTE informs the DCE that it is ready to initiate communication.

In some cases, the DTR signal is also used to control other aspects of the communication process. For example, in certain modem configurations, the DTR signal can be used to reset the modem or to indicate the end of a call.

Implementation

The DTR signal is typically implemented using a physical wire or pin in the serial communication interface. In RS-232, the DTR signal is represented by a voltage level, where a positive voltage indicates an active DTR signal and a negative voltage indicates an inactive DTR signal.

In software implementations, the DTR signal can be controlled using programming interfaces or libraries provided by the operating system or programming language. These interfaces allow developers to manipulate the DTR signal programmatically.

See Also

• RS-232 - a widely used serial communication standard
• Data Terminal Equipment (DTE) - a device that communicates with a DCE
• Data Communication Equipment (DCE) - a device that facilitates data communication
• Control Signal - signals used to control the flow of data in communication protocols