Definitions for "Data Set Ready"
This is a control signal that says that says a modem is ready to begin initial stages of transmission (i.e., configuration).
(DSR) A member of the control signal category of the RS232-C DTE-DCE interface. DSR is used to indicate that the DCE is operational.
Modem interface signal defined in RS-232 which indicates to the attached terminal equipment that the modem is attached to the telephone circuit.