RI data signal, in the context of communication and data transmission, usually refers to the "Ring Indicator" signal.
This is a control signal used to indicate that a remote communication device (such as a telephone line or modem) is sending a call signal (such as a ring signal) to a local device.
Specifically, the role and characteristics of the RI signal can be summarized as follows:
Definition and role
Definition: The RI signal is a control signal sent by a data communication device (DCE, such as a modem) to a data terminal device (DTE, such as a computer). It is used to indicate that the DCE has received a call signal from a remote communication device (such as a telephone network).
Role: When the DCE (such as a modem) receives a ring signal from a remote call, it sends a high-level signal (may be a low level in some systems, depending on the system design) to the DTE (such as a computer) through the RI signal line. After receiving this signal, the DTE can know that a remote call is coming and perform corresponding processing accordingly, such as starting the communication software, displaying a call prompt, etc.
Characteristics and implementation
Level characteristics: The RI signal usually exists in the form of a high level or a low level, depending on the system design. In most systems, the high level of the RI signal indicates that a remote call is coming.
Physical connection: The RI signal line is usually connected to the serial communication interface between the data communication equipment (DCE) and the data terminal equipment (DTE). It is a control line in the interface harness, and together with other control lines (such as DSR, DTR, RTS, CTS, etc.), it forms a complete communication control system.
Functional implementation: In the process of data communication, the implementation of the RI signal depends on the detection circuit and signal processing logic inside the DCE.
When the DCE detects a ringing signal from a remote communication device, it converts this signal into an RI signal through an internal circuit and sends it to the DTE through the RI signal line.
Application scenario
Telephone communication: In the scenario of data transmission over a telephone line, the RI signal is used to indicate a call signal on the telephone line.
When the modem receives a ringing signal from the telephone network, it notifies the computer or other data terminal equipment through the RI signal.
Remote access: In remote access systems (such as dial-up Internet access through a modem), the RI signal also plays an important role.
It helps users understand when a remote call is coming and start the corresponding communication software or application accordingly.
In summary, the RI data signal is a control signal sent by data communication equipment to data terminal equipment to indicate the arrival of a remote call.
It plays an important role in scenarios such as telephone communication and remote access, helping users to achieve reliable transmission and reception of data.