PortOpen Sets or Retrieves the state (open or closed) of the serial port. MSComm32 and SComm64 have the same syntax and functionality. Syntax:- SComm1.PortOpen = value   value:- A boolean expression indicating whether the port is open or closed   Example:- SComm1.PortOpen = True If SComm1.PortOpen = True    MessageBox.Show("Port is Open) Else    MessageBox.Show("Port is Closed") End If Remarks If you attempt to open a port that does not exist or a port that is already open then a trapable runtime error occurs.