Physical I/O Line State

The physical state of the I/O line state does not only depend on the value reported when reading LineStatus but also on the following I/O block settings: LineFormat, LineMode, and LineInverter

LineFormat	LineMode	LineInverter/LineStatus	Physical I/O line state
DIFF	Input	False/False or True/True	(VIN+ - VIN-) < VThreshold
DIFF	Input	False/True or True/False	(VIN+ - VIN-) > VThreshold or unconnected I/O line
ISO	Input	False/False or True/True	Opto coupler is OFF. The line current is < 1 mA. Line may be left unconnected or connected with the wrong polarity.
ISO	Input	False/True or True/False	Opto coupler is ON. The line current is > 1 mA.
ISO	Output	False/False or True/True	Opto coupler is OFF
ISO	Output	False/True or True/False	Opto coupler is ON
TTL	Input	False/False or True/True	The line voltage is < 0.8 Volt.
TTL	Input	False/True or True/False	The line voltage is > 2.0 Volt.
TTL	Output	False/False or True/True	The line is driven LOW.
TTL	Output	False/True or True/False	The line is driven HIGH.
TTL	DriveLow	False/False or True/True	The line is driven LOW.
TTL	DriveLow	False/True or True/False	The line voltage is > 2.0 Volt.
TTL	DriveHigh	False/False or True/True	The line voltage is < 0.8 Volt.
TTL	DriveHigh	False/True or True/False	The line is driven HIGH.