.portstate Property

Function:	Sets/returns the state of the currently selected I/O port (selection is made through the io.portnum property).
Type:	Byte
Value Range:	0-255. The default value is hardware-dependent.
See Also:	Line/Port Manipulation With Preselection, io.portenabled

Details

Each I/O port groups eight I/O lines. Each bit of this property's byte value corresponds to one "member" I/O line.

There are a few situations in which an exception may be thrown when getting or setting this property. For more information, see Handling Exceptions.

Getting the Property
Exception	Root Cause(s)
std::invalid_argument	The selected I/O port number is invalid. An I/O line number of the selected port number is invalid.
std::system_error	There was an error reading the value of an I/O line of the selected port.

Setting the Property
Exception	Root Cause(s)
std::invalid_argument	The selected I/O port number is invalid. An I/O line number of the selected port number is invalid.
std::system_error	The state of an I/O line of the selected port cannot be set because it is currently in use.