The three Write Status attributes/properties are useful for observing the progress of your generation.
The Current Write Position is the place in the buffer where the next write begins if the Relative To attribute/property is Current Write Position and the Offset is 0. In any case, the Current Write Position is always where the last write left it.
Total Samples per Channel Generated is the total number of samples per channel generated by your device since the task started.
Space Available in Buffer is computed by first calculating the Current Write Position based on the settings of the Relative To and Offset attributes/properties and then subtracting this number from the sum of Total Samples per Channel Generated and the buffer size. If regeneration is allowed, the Space Available in Buffer value is capped at the buffer size and grows from 0 to the buffer size repeatedly.