X3-SD, snap example code, Elapsed Time is always 0.0

[pitaro]

When performing data collections, the elapsed time is always displayed as 0.0 seconds. Is this meant to be the elapsed time of a single data collection, or is it perhaps the elapsed time of some message traffic?

[jhenderson]

To which "elapsed-time" are you referring? The initial input trigger always occurs at time=0, since the internal counter used by the alert mechanism is reset to zero at stream start. The timestamp rollover alert fires when this counter rolls from the max 32-bit value to zero.

[pitaro]

Status messages are displayed in the "Event Log" on the bottom pane of the snap UI. Snap is set for a single channel collection at 100,000 Hz sample rate and 100,000 samples length. When the collection is started, the following status messages are displayed in the Event Log.

Analog I/O started
Stream Mode started
Actual sampling rate: 99.9184 KHz

When the collection is finished, the following status messages are displayed in the Event Log.

Analog I/O Stopped
Stream Mode Stopped automatically
Elapsed (S): 0.000

My question was regarding the last entry in the Event Log. What is "Elapsed" meant to represent? If it is the collection length in seconds, I would expect it to read 1.000, give or take depending on the number of samples actually collected and the actual sample rate.

[jhenderson]

This appears to be a bug. It appears that the Innovative::Stopwatch object Clock is not started properly. To fix this, add the following line to following the call to Stream.Start within the StartStreaming method: