The DSROutflowControl property determines whether data outflow control is enabled when there is a Data Set Ready (DSR) condition. ...

The DSROutflowControl property determines whether data outflow control is enabled when there is a Data Set Ready (DSR) condition. DSR signals that the connection has been established by the devices on the serial connection.
Values: TRUE or FALSE. If TRUE, DSR data transmission is suspended until DSR signal is given.