Parallel I/O Control Capabilities of CVL

CVL provides the following capabilities for controlling parallel I/O output lines:

Enable/disable line. An output line can be enabled or disabled, but must be enabled before any use. Disabling a line may leave its state floating or undetermined. For a bidirectional TTL line, enabling with the output function sets the line as a TTL output line. On some frame grabbers, setting one bidirectional TTL line as an output line also sets all of that frame grabber’s bidirectional lines as output lines.
Set line state. You can set the state of an output line high (logic 1) or low (logic 0) by means of the ccOutputLine::set(polarity) member function. The effect of set(true) depends on whether the line is TTL or opto-isolated, as described in Enabling and Setting a ccOutputLine.
Get line state. You can request the status of an output line with the ccOutputLine::get() member function. A returned value of true indicates the line’s state is high.
Toggle line state. You can toggle the line’s state to its opposite state.
Pulse line. You can generate a pulse of specified polarity and width (subject to granularity limitations).

CVL provides the following capabilities for controlling parallel I/O input lines:

Enable/disable line. An input line can be enabled or disabled, but must be enabled before any use. Disabling a line may leave its state floating or undetermined. For a bidirectional TTL line, enabling with the input function sets the line as a TTL input line. On some frame grabbers, setting one bidirectional TTL line as an input line also sets all of that frame grabber’s bidirectional lines as input lines.
Get line state. You can request the status of an input line with the ccInputLine::get() member function. A returned value of true indicates the line’s state is high.
Enable callback. You can specify a callback function to be run on detection of a signal on an input line, and you can specify the incoming signal’s polarity state that qualifies as a detection.