DSR (Data Set Ready)

Data Set Ready (DSR) is a signal that is sent by a peripheral device to a computer or host system, indicating that it is ready to receive or transmit data. It is an important communication protocol used in computer systems, particularly in serial communication interfaces, such as RS-232, RS-485, and USB.

DSR is an electrical signal that is transmitted over a communication line or cable between a peripheral device and a computer or host system. It is a binary signal that can have two states: high or low. When DSR is high, it indicates that the peripheral device is ready to receive or transmit data, while when DSR is low, it indicates that the device is not ready.

DSR is one of the control signals that are used in serial communication interfaces. The other control signals are Data Terminal Ready (DTR), Request to Send (RTS), Clear to Send (CTS), and Carrier Detect (CD). These signals are used to establish and maintain the communication link between the peripheral device and the computer or host system.

DSR is typically used in conjunction with the DTR signal. When the computer or host system wants to communicate with the peripheral device, it sets the DTR signal to high, indicating that it is ready to transmit data. The peripheral device responds by setting the DSR signal to high, indicating that it is ready to receive data. The computer or host system can then send data to the peripheral device.

Similarly, when the peripheral device wants to communicate with the computer or host system, it sets the DTR signal to low, indicating that it is ready to receive data. The computer or host system responds by setting the DSR signal to low, indicating that it is not ready to receive data. The peripheral device can then wait until the DSR signal is high before sending data to the computer or host system.

DSR is also used as a flow control signal in some serial communication interfaces. In this case, it is used to prevent data loss due to overloading the receiver. When the receiver's buffer is full, it sets the DSR signal to low, indicating to the sender to stop sending data. When the receiver's buffer is empty, it sets the DSR signal to high, indicating to the sender to resume sending data.

DSR is an important signal in serial communication interfaces because it provides a mechanism for the peripheral device and the computer or host system to communicate and coordinate their actions. Without DSR, it would be difficult for the two devices to communicate effectively, and data loss and other errors could occur.

DSR is also used in other communication protocols, such as USB, where it is used to indicate that a device is ready to exchange data with the host. In USB, DSR is known as the Data Set Ready (DSR) handshake, and it is used to signal that a device is ready to receive or send data.

In summary, Data Set Ready (DSR) is a signal that is sent by a peripheral device to a computer or host system, indicating that it is ready to receive or transmit data. It is an important communication protocol used in serial communication interfaces, such as RS-232, RS-485, and USB, and is used to establish and maintain the communication link between the peripheral device and the computer or host system. DSR is also used as a flow control signal in some serial communication interfaces, and without it, data loss and other errors could occur.